Are these 19 eccentric asteroids from other star systems?

Illustration depicting one of the Centaur asteroids, which the researchers think originated from interstellar space. It was orbiting the sun in an orbit highly perpendicular to the protoplanetary disk of dust and gas, and still maintains that orbit today. Image via NASA/ CNRS.

You likely heard about ‘Oumuamua, the strange asteroid-like object that entered our solar system from interstellar space in 2017. More recently, astronomers found a second interstellar object – definitely a comet this time, labeled 21/Borisov – in 2019. Both of those objects were only visitors to our solar system, passing through for a time before heading back out into interstellar space. Meanwhile, in 2018, with less fanfare, the asteroid 2015 BZ509 – nicknamed Bee-Zed, and officially named Ka’epaoka’wela – was also identified as being of interstellar origin. But this asteroid isn’t just passing through. It’s a permanent member of our solar system, orbiting the sun. Now, researchers from the French National Centre for Scientific Research (CNRS) say they’ve found the first known population of 19 interstellar asteroids, now-permanent members of our solar system that apparently originated from somewhere else in space.

Like 2015 BZ509, they are permanent residents of the solar system, belonging to a group of objects called Centaurs, small rocky bodies orbiting between the Trojan asteroids near Jupiter and the Kuiper Belt objects beyond Neptune.

The 19 new interstellar asteroids are in highly inclined orbits in contrast to other asteroids, comets or planets in our solar system.

The Centaurs (red dots) are small rocky objects generally between the Kuiper Belt beyond Neptune (N) and the Trojans near Jupiter (J). Image via WilyD/ Wikipedia.

The new peer-reviewed findings were published in the journal Monthly Notices of the Royal Astronomical Society (MNRAS) on April 23, 2020. The study was conducted by lead author Fathi Namouni, a CNRS researcher in the Laboratoire Lagrange and Helena Morais, researcher at UNESP in Brazil.

While these asteroids have been orbiting the sun for a long time, they did not originate here, according to the new research. Analysis indicates that they were not part of the original protoplanetary disk of dust and gas that surrounded our sun when it was first born 4.5 billion years ago, where the young planets were forming, so they must have come here from somewhere else. Namouni said in a statement:

The close proximity of the stars meant that they felt each others’ gravity much more strongly in those early days than they do today. This enabled asteroids to be pulled from one star system to another.

2015 BZ509, discovered in 2018, was the first permanent asteroid in the solar system (unlike ‘Oumuamua or 21/Borisov) determined to have originated from interstellar space. Image via Christian Veillet/ Large Binocular Telescope Observatory/ CNRS.

So how did Namouni and Morais determine the interstellar origin of these asteroids?

They developed a precise computer simulation of the orbits of these asteroids. By doing so, they could “go back in time” to find out what the positions of the asteroids were in the distant past. The simulations showed that, like now, the asteroids were eccentric, orbiting the sun highly perpendicularly to the orbits of the young planets and other objects at the time. They were also located far away from the protoplanetary disk itself. These two findings indicate that the asteroids did not form in the protoplanetary disk along with all the other objects in our solar system, but rather they must have originated from somewhere else, perhaps around another star, and were caught by the sun’s gravity early in the solar system’s history.

Morais commented:

The discovery of a whole population of asteroids of interstellar origin is an important step in understanding the physical and chemical similarities and differences between solar system-born and interstellar asteroids. This population will give us clues about the sun’s early birth cluster, how interstellar asteroid capture occurred, and the role that interstellar matter had in chemically enriching the solar system and shaping its evolution.

Artist’s concept of ‘Oumuamua, whose actual appearance is unknown. While it was actually the first rocky interstellar visitor identified, in 2017, it didn’t remain in our solar system like the asteroids discussed in the new study have. Image via ESO/ M. Kornmesser.

These asteroids are similar to 2015 BZ509, which shares an orbit with Jupiter, but is traveling in the opposite direction. In 2018, the same researchers, Namouni and Morais, found that the asteroid has always had that retrograde orbit, going back to the birth of the solar system. This suggested it came from a nearby star system, and was captured by Jupiter’s gravity. 2015 BZ509 was first spotted in the Pan-STARRS survey in 2015.

It’s still possible that there could be another explanation for asteroids like these, but as they explained in a recent Gizmodo article on April 23, 2020, Namouni and Morais seem confident in their conclusions. They’ve faced some skepticism from other scientists, but so far no peer-reviewed papers have been published refuting their results. Only time will tell if their results continue to stand up to scrutiny, but at the moment, it seems that they have established a good case for some Centaurs (and perhaps some other similar objects in the solar system?) having an extraterrestrial origin.

Fathi Namouni of CNRS, lead author of the new study. Image via OCA.

Objects like ‘Oumuamua and 21/Borisov were more difficult to study, since they were only in our solar system for a relatively short amount of time. But these other 19 asteroids, although far away from Earth, keep orbiting the sun, making it easier to observe them remotely over long time periods. If they truly are interstellar, then they offer a unique opportunity to examine asteroids that are alien to our solar system, and compare them to asteroids that were already here when the solar system began to form. Additional analysis could show how they differ in appearance or composition to asteroids that formed here, and provide valuable clues as to how asteroids and other rocky bodies form around other stars.

Bottom line: A new study from CNRS reveals that 19 asteroids in our solar system are actually of interstellar origin.

Source: An interstellar origin for high-inclination Centaurs

Via CNRS

Via RAS

from EarthSky https://ift.tt/2VHo2Ea

Illustration depicting one of the Centaur asteroids, which the researchers think originated from interstellar space. It was orbiting the sun in an orbit highly perpendicular to the protoplanetary disk of dust and gas, and still maintains that orbit today. Image via NASA/ CNRS.

You likely heard about ‘Oumuamua, the strange asteroid-like object that entered our solar system from interstellar space in 2017. More recently, astronomers found a second interstellar object – definitely a comet this time, labeled 21/Borisov – in 2019. Both of those objects were only visitors to our solar system, passing through for a time before heading back out into interstellar space. Meanwhile, in 2018, with less fanfare, the asteroid 2015 BZ509 – nicknamed Bee-Zed, and officially named Ka’epaoka’wela – was also identified as being of interstellar origin. But this asteroid isn’t just passing through. It’s a permanent member of our solar system, orbiting the sun. Now, researchers from the French National Centre for Scientific Research (CNRS) say they’ve found the first known population of 19 interstellar asteroids, now-permanent members of our solar system that apparently originated from somewhere else in space.

Like 2015 BZ509, they are permanent residents of the solar system, belonging to a group of objects called Centaurs, small rocky bodies orbiting between the Trojan asteroids near Jupiter and the Kuiper Belt objects beyond Neptune.

The 19 new interstellar asteroids are in highly inclined orbits in contrast to other asteroids, comets or planets in our solar system.

The Centaurs (red dots) are small rocky objects generally between the Kuiper Belt beyond Neptune (N) and the Trojans near Jupiter (J). Image via WilyD/ Wikipedia.

The new peer-reviewed findings were published in the journal Monthly Notices of the Royal Astronomical Society (MNRAS) on April 23, 2020. The study was conducted by lead author Fathi Namouni, a CNRS researcher in the Laboratoire Lagrange and Helena Morais, researcher at UNESP in Brazil.

While these asteroids have been orbiting the sun for a long time, they did not originate here, according to the new research. Analysis indicates that they were not part of the original protoplanetary disk of dust and gas that surrounded our sun when it was first born 4.5 billion years ago, where the young planets were forming, so they must have come here from somewhere else. Namouni said in a statement:

The close proximity of the stars meant that they felt each others’ gravity much more strongly in those early days than they do today. This enabled asteroids to be pulled from one star system to another.

2015 BZ509, discovered in 2018, was the first permanent asteroid in the solar system (unlike ‘Oumuamua or 21/Borisov) determined to have originated from interstellar space. Image via Christian Veillet/ Large Binocular Telescope Observatory/ CNRS.

So how did Namouni and Morais determine the interstellar origin of these asteroids?

They developed a precise computer simulation of the orbits of these asteroids. By doing so, they could “go back in time” to find out what the positions of the asteroids were in the distant past. The simulations showed that, like now, the asteroids were eccentric, orbiting the sun highly perpendicularly to the orbits of the young planets and other objects at the time. They were also located far away from the protoplanetary disk itself. These two findings indicate that the asteroids did not form in the protoplanetary disk along with all the other objects in our solar system, but rather they must have originated from somewhere else, perhaps around another star, and were caught by the sun’s gravity early in the solar system’s history.

Morais commented:

The discovery of a whole population of asteroids of interstellar origin is an important step in understanding the physical and chemical similarities and differences between solar system-born and interstellar asteroids. This population will give us clues about the sun’s early birth cluster, how interstellar asteroid capture occurred, and the role that interstellar matter had in chemically enriching the solar system and shaping its evolution.

Artist’s concept of ‘Oumuamua, whose actual appearance is unknown. While it was actually the first rocky interstellar visitor identified, in 2017, it didn’t remain in our solar system like the asteroids discussed in the new study have. Image via ESO/ M. Kornmesser.

These asteroids are similar to 2015 BZ509, which shares an orbit with Jupiter, but is traveling in the opposite direction. In 2018, the same researchers, Namouni and Morais, found that the asteroid has always had that retrograde orbit, going back to the birth of the solar system. This suggested it came from a nearby star system, and was captured by Jupiter’s gravity. 2015 BZ509 was first spotted in the Pan-STARRS survey in 2015.

It’s still possible that there could be another explanation for asteroids like these, but as they explained in a recent Gizmodo article on April 23, 2020, Namouni and Morais seem confident in their conclusions. They’ve faced some skepticism from other scientists, but so far no peer-reviewed papers have been published refuting their results. Only time will tell if their results continue to stand up to scrutiny, but at the moment, it seems that they have established a good case for some Centaurs (and perhaps some other similar objects in the solar system?) having an extraterrestrial origin.

Fathi Namouni of CNRS, lead author of the new study. Image via OCA.

Objects like ‘Oumuamua and 21/Borisov were more difficult to study, since they were only in our solar system for a relatively short amount of time. But these other 19 asteroids, although far away from Earth, keep orbiting the sun, making it easier to observe them remotely over long time periods. If they truly are interstellar, then they offer a unique opportunity to examine asteroids that are alien to our solar system, and compare them to asteroids that were already here when the solar system began to form. Additional analysis could show how they differ in appearance or composition to asteroids that formed here, and provide valuable clues as to how asteroids and other rocky bodies form around other stars.

Bottom line: A new study from CNRS reveals that 19 asteroids in our solar system are actually of interstellar origin.

Source: An interstellar origin for high-inclination Centaurs

Via CNRS

Via RAS

from EarthSky https://ift.tt/2VHo2Ea

Are giant magnetic bubbles depleting Uranus’ atmosphere?

Animated GIF depicting Uranus’ magnetic field. Huge magnetic bubbles in that field are causing the planet’s atmosphere to slowly leak into space, according to a new study of old Voyager 2 data. Image via NASA/ Scientific Visualization Studio/ Tom Bridgman.

Uranus is an oddball planet in our solar system. It’s the only planet that rotates almost completely on its side, with respect to the flat plane in which the planets travel around our sun. Its sideways rotation is thought to be due to an ancient collision with another large body, a few billion years ago. In late March 2020, NASA announced that an analysis of data sent back by Voyager 2 – way back in 1986 – has revealed another intriguing secret about this ice giant world: the planet’s huge magnetic field appears to be siphoning its atmosphere off into space.

The finding was is based on a peer-reviewed paper first published in Geophysical Research Letters on August 9, 2019.

Voyager 2 conducted the first – and so far only – close flyby of Uranus on January 24, 1986, coming within 50,600 miles (81,433 km) of the ice giant’s cloud tops. The spacecraft made a number of important discoveries, including 11 new moons and two rings. It confirmed that temperatures on this distant world are bitterly cold, at minus 353 degrees Fahrenheit (minus 214 degrees Celsius).

The Voyager 2 data on Uranus – the only data on Uranus collected so far by a spacecraft – has kept scientists busy for decades. This newest research shows that, unknown at the time, that Voyager 2 flew through a giant magnetic bubble called a plasmoid. That bubble is also causing Uranus’ atmosphere to slowly leak into space, according to the new study.

Uranus as seen by Voyager 2 on January 14, 1986. Image via NASA/ JPL-Caltech.

Planetary atmospheres do leak slowly into space, over periods of billions of years. Earth’s atmosphere is no exception. Mars is another great example, as explained by Gina DiBraccio, space physicist at NASA’s Goddard Space Flight Center in a statement:

Mars used to be a wet planet with a thick atmosphere. It evolved over time to become the dry planet we see today.

These scientists said that a planet’s magnetic field has a lot of impact on how easily, or not, its atmosphere is able to escape. A strong magnetic field can either protect the atmosphere or actually enhance the escape process when different magnetic field lines become entangled with each other. But as Voyager 2 found, Uranus’ magnetic field was unique, weird even. According to DiBraccio:

The structure, the way that it moves … Uranus is really on its own.

Magnetometer data from Voyager 2’s flyby of Uranus in 1986. The zig-zag feature is where the spacecraft flew through a plasmoid. Image via NASA/ Dan Gershman.

So just what makes Uranus’ magnetic field so unusual?

It has to do with that sideways spin of Uranus on its axis, mentioned at the top of this post. As Uranus rotates – once about every 17 Earth-hours – the axis of its magnetic field points away from the axis of the planet itself by about 60 degrees. This causes the magnetic field to wobble, the scientists said, like a badly thrown football. DiBraccio was intrigued by this and, along with co-author Dan Gershman, took a closer look at the data from Voyager 2.

Voyager 2’s magnetometer readings would hold the clues leading to the scientists’ discovery. When the researchers zoomed into the readings, plotting a new datapoint every 1.92 seconds, they found something interesting: a small zig-zag on the graph in an otherwise smoother line. Gershman asked DiBraccio:

Do you think that could be … a plasmoid?

Plasmoids are huge bubbles of plasma – electrified gas – that are pinched off the end of a planet’s magnetotail. The magnetotail is part of the planetary magnetic field, blown back by the solar wind from the sun, kind of like a windsock. As plasmoids are pinched off and escape into space, they take ions from the atmosphere with them. This can even change the composition of the atmosphere. Earth has a magnetotail, as do some other planets, but it wasn’t known if Uranus did … until now.

But was this squiggle on the graph really a plasmoid? As DiBraccio concluded:

I think it definitely is.

The results showed that not only did Uranus have plasmoids, but that Voyager 2 actually flew right through one. It was a brief encounter, accounting for only 60 seconds of the 45 hours that the spacecraft was in encounter mode with Uranus. It might have just been a blip on the graph, but as Gershman noted, it had a real, defined shape to it:

But if you plotted it in 3D, it would look like a cylinder.

Further analysis of the data showed that the plasmoid was approximately 127,000 miles (204,000 km) long, and about 250,000 miles (400,000 km) across. This plasmoid was also different from some others; it had smooth, closed magnetic loops instead of a twisted internal magnetic field. This was a big clue pointing to how Uranus’ atmosphere leaks into space. These types of looped plasmoids  tend to form when bits of a planet’s atmosphere are siphoned off into space. According to Gershman:

Centrifugal forces take over, and the plasmoid pinches off.

The researchers estimate that anywhere from 15% to 50% of Uranus’ atmosphere could have been lost to space this way. That’s more than even Jupiter or Saturn. Unfortunately, the observations from Voyager 2 are the only close-up ones we have so far, so it’s hard to tell just how much Uranus’ atmosphere has been affected over its history.

Gina DiBraccio at NASA’s Goddard Space Flight Center (GSFC), one of the authors of the new paper. Image via GSFC.

According to DiBraccio:

Imagine if one spacecraft just flew through this room and tried to characterize the entire Earth. Obviously it’s not going to show you anything about what the Sahara or Antarctica is like. It’s why I love planetary science. You’re always going somewhere you don’t really know.

New missions to both Uranus and Neptune are being proposed, although they’re still only in the earliest stages, the proposal stages, right now. Only with new space missions can we learn more about just how Uranus’ magnetic field is affecting its atmosphere, and study its rings and moons in much more detail. And could the same kind of magnetic field and atmosphere interaction also be happening at Neptune, the other ice giant in our solar system? Uranus and Neptune appear similar at first glance, although they do have distinct differences, as well.

Seeing these two worlds up close again for the first time in decades would be an epic adventure.

Bottom line: Researchers looking at old data about Uranus from Voyager 2 have found evidence that plasmoids are slowly causing the planet’s atmosphere to leak into space.

Source: Voyager 2 constraints on plasmoid-based transport at Uranus

Via NASA

from EarthSky https://ift.tt/2YaMQ90

Animated GIF depicting Uranus’ magnetic field. Huge magnetic bubbles in that field are causing the planet’s atmosphere to slowly leak into space, according to a new study of old Voyager 2 data. Image via NASA/ Scientific Visualization Studio/ Tom Bridgman.

Uranus is an oddball planet in our solar system. It’s the only planet that rotates almost completely on its side, with respect to the flat plane in which the planets travel around our sun. Its sideways rotation is thought to be due to an ancient collision with another large body, a few billion years ago. In late March 2020, NASA announced that an analysis of data sent back by Voyager 2 – way back in 1986 – has revealed another intriguing secret about this ice giant world: the planet’s huge magnetic field appears to be siphoning its atmosphere off into space.

The finding was is based on a peer-reviewed paper first published in Geophysical Research Letters on August 9, 2019.

Voyager 2 conducted the first – and so far only – close flyby of Uranus on January 24, 1986, coming within 50,600 miles (81,433 km) of the ice giant’s cloud tops. The spacecraft made a number of important discoveries, including 11 new moons and two rings. It confirmed that temperatures on this distant world are bitterly cold, at minus 353 degrees Fahrenheit (minus 214 degrees Celsius).

The Voyager 2 data on Uranus – the only data on Uranus collected so far by a spacecraft – has kept scientists busy for decades. This newest research shows that, unknown at the time, that Voyager 2 flew through a giant magnetic bubble called a plasmoid. That bubble is also causing Uranus’ atmosphere to slowly leak into space, according to the new study.

Uranus as seen by Voyager 2 on January 14, 1986. Image via NASA/ JPL-Caltech.

Planetary atmospheres do leak slowly into space, over periods of billions of years. Earth’s atmosphere is no exception. Mars is another great example, as explained by Gina DiBraccio, space physicist at NASA’s Goddard Space Flight Center in a statement:

Mars used to be a wet planet with a thick atmosphere. It evolved over time to become the dry planet we see today.

These scientists said that a planet’s magnetic field has a lot of impact on how easily, or not, its atmosphere is able to escape. A strong magnetic field can either protect the atmosphere or actually enhance the escape process when different magnetic field lines become entangled with each other. But as Voyager 2 found, Uranus’ magnetic field was unique, weird even. According to DiBraccio:

The structure, the way that it moves … Uranus is really on its own.

Magnetometer data from Voyager 2’s flyby of Uranus in 1986. The zig-zag feature is where the spacecraft flew through a plasmoid. Image via NASA/ Dan Gershman.

So just what makes Uranus’ magnetic field so unusual?

It has to do with that sideways spin of Uranus on its axis, mentioned at the top of this post. As Uranus rotates – once about every 17 Earth-hours – the axis of its magnetic field points away from the axis of the planet itself by about 60 degrees. This causes the magnetic field to wobble, the scientists said, like a badly thrown football. DiBraccio was intrigued by this and, along with co-author Dan Gershman, took a closer look at the data from Voyager 2.

Voyager 2’s magnetometer readings would hold the clues leading to the scientists’ discovery. When the researchers zoomed into the readings, plotting a new datapoint every 1.92 seconds, they found something interesting: a small zig-zag on the graph in an otherwise smoother line. Gershman asked DiBraccio:

Do you think that could be … a plasmoid?

Plasmoids are huge bubbles of plasma – electrified gas – that are pinched off the end of a planet’s magnetotail. The magnetotail is part of the planetary magnetic field, blown back by the solar wind from the sun, kind of like a windsock. As plasmoids are pinched off and escape into space, they take ions from the atmosphere with them. This can even change the composition of the atmosphere. Earth has a magnetotail, as do some other planets, but it wasn’t known if Uranus did … until now.

But was this squiggle on the graph really a plasmoid? As DiBraccio concluded:

I think it definitely is.

The results showed that not only did Uranus have plasmoids, but that Voyager 2 actually flew right through one. It was a brief encounter, accounting for only 60 seconds of the 45 hours that the spacecraft was in encounter mode with Uranus. It might have just been a blip on the graph, but as Gershman noted, it had a real, defined shape to it:

But if you plotted it in 3D, it would look like a cylinder.

Further analysis of the data showed that the plasmoid was approximately 127,000 miles (204,000 km) long, and about 250,000 miles (400,000 km) across. This plasmoid was also different from some others; it had smooth, closed magnetic loops instead of a twisted internal magnetic field. This was a big clue pointing to how Uranus’ atmosphere leaks into space. These types of looped plasmoids  tend to form when bits of a planet’s atmosphere are siphoned off into space. According to Gershman:

Centrifugal forces take over, and the plasmoid pinches off.

The researchers estimate that anywhere from 15% to 50% of Uranus’ atmosphere could have been lost to space this way. That’s more than even Jupiter or Saturn. Unfortunately, the observations from Voyager 2 are the only close-up ones we have so far, so it’s hard to tell just how much Uranus’ atmosphere has been affected over its history.

Gina DiBraccio at NASA’s Goddard Space Flight Center (GSFC), one of the authors of the new paper. Image via GSFC.

According to DiBraccio:

Imagine if one spacecraft just flew through this room and tried to characterize the entire Earth. Obviously it’s not going to show you anything about what the Sahara or Antarctica is like. It’s why I love planetary science. You’re always going somewhere you don’t really know.

New missions to both Uranus and Neptune are being proposed, although they’re still only in the earliest stages, the proposal stages, right now. Only with new space missions can we learn more about just how Uranus’ magnetic field is affecting its atmosphere, and study its rings and moons in much more detail. And could the same kind of magnetic field and atmosphere interaction also be happening at Neptune, the other ice giant in our solar system? Uranus and Neptune appear similar at first glance, although they do have distinct differences, as well.

Seeing these two worlds up close again for the first time in decades would be an epic adventure.

Bottom line: Researchers looking at old data about Uranus from Voyager 2 have found evidence that plasmoids are slowly causing the planet’s atmosphere to leak into space.

Source: Voyager 2 constraints on plasmoid-based transport at Uranus

Via NASA

from EarthSky https://ift.tt/2YaMQ90

Coronavirus reports part 1: “I’m taking things week by week”

We caught up with people living with cancer across the country, to find out how the pandemic was affecting them, their families and their treatment.

Jean: “Never have I been so aware of the teamwork to look after people”

Jean getting ready to go to the hospital.

Jean was originally diagnosed with non-Hodgkin lymphoma in July 2006.

She’s had a number of different treatments since, and has just finished 4 rounds of chemotherapy in Southampton, which she started before the virus arrived in the UK.

Initially, her treatment began as planned, but as the coronavirus pandemic worsened it became clear that adjustments would have to be made. She says that COVID-19 has “taken over oncology” at Southampton General Hospital, where Jean usually has her treatment.

“I had my first round of chemo in the General Hospital, but oncology has moved to the Spire Hospital now – I have my 2nd, 3rd and 4th round there.”

The privately-run Spire Southampton Hospital, opposite the General Hospital, has been repurposed to allow some people to get cancer treatment, which has been a welcome change for Jean.

“When I went for the second round, I realised I had been scared going into the General and it felt safer at the Spire. But the staff have had to get used to the new surroundings.” Jean says she noticed an unease amongst staff, “they’re all amazing but it is unsettling for everyone”.

She had also been due to have a longer treatment of rituximab and bendamustine over 6 months, but this has been changed due to COVID-19.

“As bendamustine is known to attack the immune system, my treatment was changed to one day each week for a month using rituximab and no bendamustine, so that my immune system is as strong as possible.”

Outside treatment, Jean is relying on family to get her through the isolation, which she feels is “akin to having had cancer.”

It’s a worrying time. “When I have cancer treatment, the only places I feel safe are in oncology and at home.

“I feel fortunate to be looked at by my professor at the hospital and my husband at home.”

Alfred: “Those appointments are my lifesaver”

Alfred taking his daily exercise.

“There is a lot of misinformation out there. People are scared.” Alfred was diagnosed with advanced prostate cancer in 2012. He was due to have an appointment at Mount Vernon Hospital in Hillingdon in May, but it was cancelled.

“That’s a chronic pain relief appointment, the one for my bloods has been moved too. I will still go in the day before, but that will be in a different part of the building.” Alfred says he’ll likely get the results of the blood tests over the phone instead.

“Those appointments are my lifesaver. Take that away and I have worries.” Alfred’s also concerned for his partner, who works at a hospital. “She’s not in the ward, but she’s still so close and I worry so much.”

And he has changed his routes for his daily exercise too. “I was getting interrupted by coming across people who were not social distancing and I was in danger of getting into too many arguments – I have found a much quieter place to walk now!”

Cory: “I’m going to miss my next treatment cycle – for me it seemed like the right thing to do”

Cory in his garden.

“I went in a couple of weeks ago for treatment. They had asked me the week before if I still wanted to come in and I said that I was pleased that they asked, but I was happy to.” Cory, who was diagnosed in 2015 with Ewing’s sarcoma – a rare type of cancer that mainly affects children and young people – says that the UK-wide lockdown started just after that call.

“It all kicked off that weekend – there was a weird atmosphere on the ward. It’s a sterile environment anyway, but there was a lot of distancing.”

Since then, Cory’s doctors called him to see how he felt about the next cycle.

“I’m going to miss that – for me, realistically, it seemed the right thing to do – it was my decision and I have to be so conscious of the risk factors.

“If I get COVID19, that could be a real issue for me – that could be it.”

Having been on treatment for a long time, Cory felt ok with taking a break in the cycle. He plans to review the decision again for the next round of treatment. “I’m due to have a scan around then so I should have that.”

Beyond the hospital, Cory says that being in isolation “feels like old news”.

“It’s what my life has been like for years, with all the infection control and washing hands. If anything, it’s a relief that there is no pressure to go out – no one is inviting me to be anywhere, so I don’t have to say no at the moment.”

Nicky: “They said I would see them when I turned up in the car park of the cancer centre”

Nicky picking up her latest prescription.

Nicky was diagnosed with incurable breast cancer in 2018. “I’m on oral chemo at the moment and I have monthly bloods.” Nicky talked to her nurse team when the COVID-19 letters started to come out about her next blood test, which was due to be the following week.

“They said they would probably be doing drive-by bloods by then, as they were not letting anyone into the hospital unless they had to.” Nicky got a call the morning of her blood test and an email with more information about where to do. “They said I would see them when I turned up in the car park of the cancer centre.

“I drove in and two of them were there waving – they were in their apron and gloves and told me not to get out of the car. I wound down my window and put my arm out. It took just minutes.”

The nurses then told her to drive to pharmacy, which was in the same carpark. “I pulled up to a hatch and gave my name and my name and date of birth and I was off in 4 minutes!”

Later that week, Nicky got a call to say her bloods were normal. “I usually go into the clinic but had the appointment on the phone.”

Nicky says the temporary set up worked well for her, but she’s due a scan next month and doesn’t know how it will be affected.

“My biggest anxiety is that, as I’m stage 4, a month can make a big difference – a delay of a month can be the difference between life and death.”

She’s particularly worried about the impact coronavirus is having on clinical trials and research. “It’s a big concern. I live in the hope of new treatment lines being created. If that’s held being held up, it could potentially take years off my life.

“But the way I’ve dealt with having stage 4 cancer is that I try not to think too far ahead, instead focusing on the day in front of me.” For now, Nicky’s on oral chemo and feels ok. “I’m taking things week by week. I will deal with next month’s scans next month”

Nicky says it’s been interesting to see how people have reacted to the coronavirus pandemic. “Everyone else is now worrying about germs and infections and washing their hands – that’s how I’ve been living for a long time.”

Katie

Thanks to Jean, Alfred, Cory and Nicky for sharing their experiences. If you would like to share your story with us, please visit our website. 

If you have questions about cancer, you can talk to our nurses Monday to Friday, 9-5pm, on freephone 0808 800 4040.

from Cancer Research UK – Science blog https://ift.tt/2VHpc2z

We caught up with people living with cancer across the country, to find out how the pandemic was affecting them, their families and their treatment.

Jean: “Never have I been so aware of the teamwork to look after people”

Jean getting ready to go to the hospital.

Jean was originally diagnosed with non-Hodgkin lymphoma in July 2006.

She’s had a number of different treatments since, and has just finished 4 rounds of chemotherapy in Southampton, which she started before the virus arrived in the UK.

Initially, her treatment began as planned, but as the coronavirus pandemic worsened it became clear that adjustments would have to be made. She says that COVID-19 has “taken over oncology” at Southampton General Hospital, where Jean usually has her treatment.

“I had my first round of chemo in the General Hospital, but oncology has moved to the Spire Hospital now – I have my 2nd, 3rd and 4th round there.”

The privately-run Spire Southampton Hospital, opposite the General Hospital, has been repurposed to allow some people to get cancer treatment, which has been a welcome change for Jean.

“When I went for the second round, I realised I had been scared going into the General and it felt safer at the Spire. But the staff have had to get used to the new surroundings.” Jean says she noticed an unease amongst staff, “they’re all amazing but it is unsettling for everyone”.

She had also been due to have a longer treatment of rituximab and bendamustine over 6 months, but this has been changed due to COVID-19.

“As bendamustine is known to attack the immune system, my treatment was changed to one day each week for a month using rituximab and no bendamustine, so that my immune system is as strong as possible.”

Outside treatment, Jean is relying on family to get her through the isolation, which she feels is “akin to having had cancer.”

It’s a worrying time. “When I have cancer treatment, the only places I feel safe are in oncology and at home.

“I feel fortunate to be looked at by my professor at the hospital and my husband at home.”

Alfred: “Those appointments are my lifesaver”

Alfred taking his daily exercise.

“There is a lot of misinformation out there. People are scared.” Alfred was diagnosed with advanced prostate cancer in 2012. He was due to have an appointment at Mount Vernon Hospital in Hillingdon in May, but it was cancelled.

“That’s a chronic pain relief appointment, the one for my bloods has been moved too. I will still go in the day before, but that will be in a different part of the building.” Alfred says he’ll likely get the results of the blood tests over the phone instead.

“Those appointments are my lifesaver. Take that away and I have worries.” Alfred’s also concerned for his partner, who works at a hospital. “She’s not in the ward, but she’s still so close and I worry so much.”

And he has changed his routes for his daily exercise too. “I was getting interrupted by coming across people who were not social distancing and I was in danger of getting into too many arguments – I have found a much quieter place to walk now!”

Cory: “I’m going to miss my next treatment cycle – for me it seemed like the right thing to do”

Cory in his garden.

“I went in a couple of weeks ago for treatment. They had asked me the week before if I still wanted to come in and I said that I was pleased that they asked, but I was happy to.” Cory, who was diagnosed in 2015 with Ewing’s sarcoma – a rare type of cancer that mainly affects children and young people – says that the UK-wide lockdown started just after that call.

“It all kicked off that weekend – there was a weird atmosphere on the ward. It’s a sterile environment anyway, but there was a lot of distancing.”

Since then, Cory’s doctors called him to see how he felt about the next cycle.

“I’m going to miss that – for me, realistically, it seemed the right thing to do – it was my decision and I have to be so conscious of the risk factors.

“If I get COVID19, that could be a real issue for me – that could be it.”

Having been on treatment for a long time, Cory felt ok with taking a break in the cycle. He plans to review the decision again for the next round of treatment. “I’m due to have a scan around then so I should have that.”

Beyond the hospital, Cory says that being in isolation “feels like old news”.

“It’s what my life has been like for years, with all the infection control and washing hands. If anything, it’s a relief that there is no pressure to go out – no one is inviting me to be anywhere, so I don’t have to say no at the moment.”

Nicky: “They said I would see them when I turned up in the car park of the cancer centre”

Nicky picking up her latest prescription.

Nicky was diagnosed with incurable breast cancer in 2018. “I’m on oral chemo at the moment and I have monthly bloods.” Nicky talked to her nurse team when the COVID-19 letters started to come out about her next blood test, which was due to be the following week.

“They said they would probably be doing drive-by bloods by then, as they were not letting anyone into the hospital unless they had to.” Nicky got a call the morning of her blood test and an email with more information about where to do. “They said I would see them when I turned up in the car park of the cancer centre.

“I drove in and two of them were there waving – they were in their apron and gloves and told me not to get out of the car. I wound down my window and put my arm out. It took just minutes.”

The nurses then told her to drive to pharmacy, which was in the same carpark. “I pulled up to a hatch and gave my name and my name and date of birth and I was off in 4 minutes!”

Later that week, Nicky got a call to say her bloods were normal. “I usually go into the clinic but had the appointment on the phone.”

Nicky says the temporary set up worked well for her, but she’s due a scan next month and doesn’t know how it will be affected.

“My biggest anxiety is that, as I’m stage 4, a month can make a big difference – a delay of a month can be the difference between life and death.”

She’s particularly worried about the impact coronavirus is having on clinical trials and research. “It’s a big concern. I live in the hope of new treatment lines being created. If that’s held being held up, it could potentially take years off my life.

“But the way I’ve dealt with having stage 4 cancer is that I try not to think too far ahead, instead focusing on the day in front of me.” For now, Nicky’s on oral chemo and feels ok. “I’m taking things week by week. I will deal with next month’s scans next month”

Nicky says it’s been interesting to see how people have reacted to the coronavirus pandemic. “Everyone else is now worrying about germs and infections and washing their hands – that’s how I’ve been living for a long time.”

Katie

Thanks to Jean, Alfred, Cory and Nicky for sharing their experiences. If you would like to share your story with us, please visit our website. 

If you have questions about cancer, you can talk to our nurses Monday to Friday, 9-5pm, on freephone 0808 800 4040.

from Cancer Research UK – Science blog https://ift.tt/2VHpc2z

All you need to know: Eta Aquariid meteors

The 2013 Eta Aquariid meteor shower was fantastic as viewed from Earth’s Southern Hemisphere. Colin Legg of Australia created this composite of his experience. He wrote, “Composite of approximately 50 images containing 26 meteors, meteor train, 17% moon, zodiacal light and Pilbara desert.”

In 2020, the forecast calls for the greatest number of Eta Aquariid meteors to fall before dawn on (or near) May 5. However, this shower has a rather broad maximum, so just as many meteors may be flying on the mornings before and after. There is one big bugaboo for watching the Eta Aquariids in 2020, though. The shower will have to contend with a nearly full waxing gibbous moon. That’s why we recommend you try watching for meteors before sunup on May 1, 2 and 3. Fewer meteors will be flying then, but there will be a larger moon-free window between moonset and dawn.

This shower favors the Southern Hemisphere, ranking as one of the finest showers of the year there, in a year when the moon isn’t obscuring the show. At mid-northern latitudes, these meteors don’t fall so abundantly, although southern states in the U.S., for example, tend to see more meteors than people at more northerly latitudes.

In a dark sky – when the moon is down – especially at more southerly latitudes, the Eta Aquariids can produce up to 20 to 40 meteors per hour. From mid-northern latitudes, you might only see about 10 meteors per hour.

Why more Eta Aquariid meteors in the Southern Hemisphere?

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Meteor captured over Mount Bromo, an active volcano in Indonesia, during the 2013 Eta Aquariid shower. Photo by Justin Ng of Singapore. See more photos by Justin Ng.

When and how should I watch the Eta Aquariids? Let’s talk for a minute about the fact the Eta Aquariid shower extends on either side of its peak morning of May 5, 2020. Writing for the International Meteor Organization in 2017, veteran meteor expert Robert Lunsford pointed out:

… There is no sharp peak for this shower, but rather a plateau of good rates that last approximately one week centered on May 6.

So, in 2020, we stand by our hope that some meteors will be flying in the early morning hours on May 1, 2 and 3. But, of course, you never know.

In general, the best time to watch these fast and often bright meteors is in the hours or two before the onset of morning twilight. Don’t know when twilight begins in your part of the world? Try this link and remember to check the astronomical twilight box.

Want to know the time of moonset in your area? Click here, remembering to check the moonrise and moonset box, to find out when the moon sets in your sky.

Give yourself at least an hour of viewing time for watching any meteor shower. Meteors tend to come in spurts that are interspersed by lulls. Also, it can take as long as 20 minutes for your eyes to adapt to the dark.

You need no special equipment to watch a meteor shower, but a little luck always helps. Find a dark, open sky away from artificial lights, and sprawl out on a reclining lawn chair. Meteor watching is a lot like fishing. Sometimes you catch a good number of them, and sometimes you don’t.

Radiant point of Eta Aquariid meteor shower. It’s in the constellation Aquarius, in the southeast before dawn on May mornings, as seen from mid-northern latitudes.

A Y-shaped asterism called the Water Jar marks the radiant of the Eta Aquariid meteor shower. It’s noticeable, if your sky is dark.

Radiant point of the Eta Aquariid shower. If you trace the paths of the Eta Aquariid meteors backward, they all seem to radiate from a certain point in front of the constellation Aquarius the Water Bearer. This point on the sky’s dome is called the radiant of the meteor shower, which nearly aligns with the faint star Eta Aquarii. Hence, this meteor shower is named in honor of this star.

Eta Aquarii is one of the four stars making up the Y-shaped Water Jar asterism in the northern part of Aquarius. If you can find the Water Jar in the constellation Aquarius, you’ve as good as located the radiant point for the Eta Aquariid meteors. The alignment of the radiant and the star is of course coincidental. Eta Aquarii is some 170 light-years away – trillons upon trillions of miles away – while the Eta Aquariid meteors burn up about 60 miles (100 km) above Earth’s surface.

Meteor shower radiants are sometimes misunderstood by casual meteor-watchers. You don’t need to know where they are to watch a meteor shower. That’s because the meteors fly every which way across the sky, in front of numerous constellations. However, the higher a shower’s radiant appears in your sky, the more meteors you’re likely to see. For the Eta Aquariids, the radiant soars highest in the nighttime sky just before dawn. That’s why you can expect to see the most meteors in the wee morning hours.

You can see some Eta Aquariid meteors in late evening, before the radiant rises into your sky. In fact, late evening is the best time to see earthgrazers, meteors that make exceptionally long streaks across your sky. As the radiant rises higher – that is, as the hours of the night tick away to dawn – you’ll see shorter meteors, but more meteors.

Halley’s Comet, the parent of the May Eta Aquariid and October Orionid meteor showers. Image vuia NASA Blueshift. Dust from this comet will streak the nighttime as Eta Aquariid meteors on the mornings of May 5 and 6.

Halley’s Comet is the source of the Eta Aquariid meteor shower. Every year, our planet Earth crosses the orbital path of Halley’s Comet in late April and May, so bits and pieces from this comet light up the nighttime as Eta Aquariid meteors. This shower is said to be active from April 19 to May 20, although Earth plows most deeply into this stream of comet debris around May 5 or 6.

The comet dust smashes into Earth’s upper atmosphere at nearly 150,000 miles per hour (240,000 kilometers per hour). Roughly half of these swift-moving meteors leave persistent trains – ionized gas trails that glow for a few seconds after the meteor has passed.

Our planet also crosses the orbital path of Halley’s Comet at the other end of the year, giving rise to the Orionid meteor shower, which is usually at its best in the predawn hours on or near October 21.

Bottom line: What’s a good meteor shower for the Southern Hemisphere? It’s usually the Eta Aquariid shower. This year, 2020, a nearly full waxing gibbous moon interferes with the peak on the morning of May 5. Try watching after moonset and before dawn on the mornings of May 1, 2 and 3.

EarthSky’s meteor shower guide for 2020

from EarthSky https://ift.tt/1pRgiL8

The 2013 Eta Aquariid meteor shower was fantastic as viewed from Earth’s Southern Hemisphere. Colin Legg of Australia created this composite of his experience. He wrote, “Composite of approximately 50 images containing 26 meteors, meteor train, 17% moon, zodiacal light and Pilbara desert.”

In 2020, the forecast calls for the greatest number of Eta Aquariid meteors to fall before dawn on (or near) May 5. However, this shower has a rather broad maximum, so just as many meteors may be flying on the mornings before and after. There is one big bugaboo for watching the Eta Aquariids in 2020, though. The shower will have to contend with a nearly full waxing gibbous moon. That’s why we recommend you try watching for meteors before sunup on May 1, 2 and 3. Fewer meteors will be flying then, but there will be a larger moon-free window between moonset and dawn.

This shower favors the Southern Hemisphere, ranking as one of the finest showers of the year there, in a year when the moon isn’t obscuring the show. At mid-northern latitudes, these meteors don’t fall so abundantly, although southern states in the U.S., for example, tend to see more meteors than people at more northerly latitudes.

In a dark sky – when the moon is down – especially at more southerly latitudes, the Eta Aquariids can produce up to 20 to 40 meteors per hour. From mid-northern latitudes, you might only see about 10 meteors per hour.

Why more Eta Aquariid meteors in the Southern Hemisphere?

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Meteor captured over Mount Bromo, an active volcano in Indonesia, during the 2013 Eta Aquariid shower. Photo by Justin Ng of Singapore. See more photos by Justin Ng.

When and how should I watch the Eta Aquariids? Let’s talk for a minute about the fact the Eta Aquariid shower extends on either side of its peak morning of May 5, 2020. Writing for the International Meteor Organization in 2017, veteran meteor expert Robert Lunsford pointed out:

… There is no sharp peak for this shower, but rather a plateau of good rates that last approximately one week centered on May 6.

So, in 2020, we stand by our hope that some meteors will be flying in the early morning hours on May 1, 2 and 3. But, of course, you never know.

In general, the best time to watch these fast and often bright meteors is in the hours or two before the onset of morning twilight. Don’t know when twilight begins in your part of the world? Try this link and remember to check the astronomical twilight box.

Want to know the time of moonset in your area? Click here, remembering to check the moonrise and moonset box, to find out when the moon sets in your sky.

Give yourself at least an hour of viewing time for watching any meteor shower. Meteors tend to come in spurts that are interspersed by lulls. Also, it can take as long as 20 minutes for your eyes to adapt to the dark.

You need no special equipment to watch a meteor shower, but a little luck always helps. Find a dark, open sky away from artificial lights, and sprawl out on a reclining lawn chair. Meteor watching is a lot like fishing. Sometimes you catch a good number of them, and sometimes you don’t.

Radiant point of Eta Aquariid meteor shower. It’s in the constellation Aquarius, in the southeast before dawn on May mornings, as seen from mid-northern latitudes.

A Y-shaped asterism called the Water Jar marks the radiant of the Eta Aquariid meteor shower. It’s noticeable, if your sky is dark.

Radiant point of the Eta Aquariid shower. If you trace the paths of the Eta Aquariid meteors backward, they all seem to radiate from a certain point in front of the constellation Aquarius the Water Bearer. This point on the sky’s dome is called the radiant of the meteor shower, which nearly aligns with the faint star Eta Aquarii. Hence, this meteor shower is named in honor of this star.

Eta Aquarii is one of the four stars making up the Y-shaped Water Jar asterism in the northern part of Aquarius. If you can find the Water Jar in the constellation Aquarius, you’ve as good as located the radiant point for the Eta Aquariid meteors. The alignment of the radiant and the star is of course coincidental. Eta Aquarii is some 170 light-years away – trillons upon trillions of miles away – while the Eta Aquariid meteors burn up about 60 miles (100 km) above Earth’s surface.

Meteor shower radiants are sometimes misunderstood by casual meteor-watchers. You don’t need to know where they are to watch a meteor shower. That’s because the meteors fly every which way across the sky, in front of numerous constellations. However, the higher a shower’s radiant appears in your sky, the more meteors you’re likely to see. For the Eta Aquariids, the radiant soars highest in the nighttime sky just before dawn. That’s why you can expect to see the most meteors in the wee morning hours.

You can see some Eta Aquariid meteors in late evening, before the radiant rises into your sky. In fact, late evening is the best time to see earthgrazers, meteors that make exceptionally long streaks across your sky. As the radiant rises higher – that is, as the hours of the night tick away to dawn – you’ll see shorter meteors, but more meteors.

Halley’s Comet, the parent of the May Eta Aquariid and October Orionid meteor showers. Image vuia NASA Blueshift. Dust from this comet will streak the nighttime as Eta Aquariid meteors on the mornings of May 5 and 6.

Halley’s Comet is the source of the Eta Aquariid meteor shower. Every year, our planet Earth crosses the orbital path of Halley’s Comet in late April and May, so bits and pieces from this comet light up the nighttime as Eta Aquariid meteors. This shower is said to be active from April 19 to May 20, although Earth plows most deeply into this stream of comet debris around May 5 or 6.

The comet dust smashes into Earth’s upper atmosphere at nearly 150,000 miles per hour (240,000 kilometers per hour). Roughly half of these swift-moving meteors leave persistent trains – ionized gas trails that glow for a few seconds after the meteor has passed.

Our planet also crosses the orbital path of Halley’s Comet at the other end of the year, giving rise to the Orionid meteor shower, which is usually at its best in the predawn hours on or near October 21.

Bottom line: What’s a good meteor shower for the Southern Hemisphere? It’s usually the Eta Aquariid shower. This year, 2020, a nearly full waxing gibbous moon interferes with the peak on the morning of May 5. Try watching after moonset and before dawn on the mornings of May 1, 2 and 3.

EarthSky’s meteor shower guide for 2020

from EarthSky https://ift.tt/1pRgiL8

How coronavirus drifts through the air in microscopic droplets

Aerosols are everywhere. Image via slobo/ E+ / Getty Images.

Shelly Miller, University of Colorado Boulder

During the 1970s when I was growing up in Southern California, the air was so polluted that I was regularly sent home from high school to “shelter in place.” There might not seem to be much in common between staying home due to air pollution and staying home to fight the coronavirus pandemic, but fundamentally, both have a lot to do with aerosols.

Aerosols are the tiny floating pieces of pollution that make up Los Angeles’ famous smog, the dust particles you see floating in a ray of sunshine and also the small droplets of liquid that escape your mouth when you talk, cough or breathe. These small pieces of floating liquids can contain pieces of the coronavirus and can be a major contributor to its spread.

If you walk outside right now, chances are you will see people wearing masks and practicing social distancing. These actions are in large part meant to prevent people from spreading or inhaling aerosols.

I am a professor of mechanical engineering and study aerosols and air pollution. The more people understand how aerosols work, the better people can avoid getting or spreading the coronavirus.

Airborne and everywhere

An aerosol is a clump of small liquid or solid particles floating in the air. They are everywhere in the environment and can be made of anything small enough to float, like smoke, water or coronavirus-carrying saliva.

When a person coughs, talks or breathes, they throw anywhere between 900 to 300,000 liquid particles from their mouth. These particles range in size from microscopic – a thousandth the width of a hair – up to the size of a grain of fine beach sand. A cough can send them traveling at speeds up to 60 mph.

From your lungs into the air around you, aerosols carry coronavirus. Image via Peter Dazeley/ The Image Bank/ Getty Images.

Size of the particle and air currents affect how long they will stay in the air. In a still room, tiny particles like smoke can stay airborne for up to eight hours. Larger particles fall out of the air more quickly and land on surfaces after a few minutes.

By simply being near other people, you are coming into constant contact with aerosols from their mouth. During a pandemic this a little more concerning than normal. But the important question is not do exhaled aerosols exist, rather, how infectious are they?

The coronavirus is small and easily transported by airborne particles of saliva. Image via fotograzia/ Moment/ Getty Images.

Aerosols as virus delivery systems

The new coronavirus, SARS-CoV-2, is tiny, about 0.1 microns – roughly 4 millionths of an inch – in diameter. Aerosols produced by people when they breathe, talk and cough are generally between about 0.7 microns to around 10 microns – completely invisible to the naked eye and easily able to float in air. These particles are mostly biological fluids from people’s mouths and lungs and can contain bits of virus genetic material.

Researchers don’t yet know how many individual pieces of SARS-CoV-2 an aerosol produced by an infected person’s cough might hold. But in one preprint study, meaning it is currently under peer review, researchers used a model to estimate that a person standing and speaking in a room could release up to 114 infectious doses per hour. The researchers predict that these aerosolized bits of saliva would easily infect other people if this happened in public indoor spaces like a bank, restaurant or pharmacy.

Another thing to consider is how easy these particles are to inhale. In a recent computer model study, researchers found that people would most likely inhale aerosols from another person that is talking and coughing while sitting less than 6 feet away.

While this seems bad, the actual process from exposure to infection is a complicated numbers game. Often, viral particles found in aerosols are damaged. A study looking at the flu virus found that only 0.1% of viruses exhaled by a person are actually infectious. The coronavirus also starts to die off once it has left the body, remaining viable in the air for up to 3 hours. And of course, not every aerosol coming from an infected person will contain the coronavirus. There is a lot of chance involved.

Public health officials still don’t know whether direct contact, indirect contact through surfaces, or aerosols are the main pathway of transmission for the coronavirus. But everything experts like myself know about aerosols suggests that they could be a major pathway of transmission.

Aerosol-driven outbreaks have been linked to restaurants, shops and many other public places. Image via AP Photo/ Vincent Yu.

Evidence of aerosol transmission

It is almost impossible to study viral transmission in real time, so researchers have turned to environmental sampling and contact tracing to try to study the spread of the coronavirus in aerosols. This research is happening extremely fast and most of it is still under peer review, but these studies offer extremely interesting, if preliminary, information.

To test the environment, researchers simply sample the air. In Nebraska, scientists found airborne SARS-CoV-2 in a hospital. In China, scientists also found the virus in the air of a number of hospitals as well as a department store.

But environmental sampling alone cannot prove aerosol transmission. That requires contact tracing.

One restaurant in Guangzhou, China, was the site of a small outbreak on January 23 and offers direct evidence of aerosol transmission. Researchers believe that there was one infected but asymptomatic person sitting at a table in the restaurant. Because of the air currents circulating in the room due to air conditioning, people sitting at two other tables became infected, likely because of aerosols.

Overall, the evidence suggests that it is much more risky to be inside than outside. The reason is the lack of airflow. It takes between 15 minutes and 3 hours for an aerosol to be sucked outside by a ventilation system or float out an open window.

Another preprint study of outbreaks in Japan suggests that the chances of direct transmission are almost 20 times higher indoors compared to outdoors. In Singapore, researchers traced the first 3 outbreaks directly to a few shops, a banquet dinner and a church.

Once outside, these potentially infectious aerosols disappear in the expanse of the atmosphere and are much less of a worry. It is, of course, possible to catch the virus outside if you are in close contact with a sick person, but this seems very rare. Researchers in China found that only 1 of 314 outbreaks they examined could be traced back to outdoor contact.

There has been recent concern over aerosol transmission during running and biking. While the science is still developing on this, it is probably wise to give other bikers or runners a little more room than normal.

Wearing masks and social distancing reduce the risk of spreading or inhaling aerosols. Image via AP Photo/ Gerald Herbert.

How to reduce aerosol transmission

With all of this knowledge of how aerosols are produced, how they move and the role they play in this pandemic, an obvious question arises: what about masks?

The Centers for Disease Control and Prevention recommends wearing a face mask in any public setting where social distancing is hard to do. This is because homemade masks probably do a reasonable job of blocking aerosols from leaving your mouth. The evidence generally supports their use and more research is coming to show that masks can be very effective at reducing SARS-CoV-2 in air. Masks aren’t perfect and more studies are currently underway to learn how effective they really are, but taking this small precaution could help slow the pandemic.

Other than wearing a mask, follow common sense and the guidance of public health officials. Avoid crowded indoor spaces as much as possible. Practice social distancing both inside and outdoors. Wash your hands frequently. All of these things work to prevent the spread of the coronavirus and can help keep you from getting it. There is a significant amount of evidence that Covid-19 is transmitted by the inhalation of airborne particles, but by carefully following the advice of experts, individuals can minimize the risk they pose.

Shelly Miller, Professor of Mechanical and Environmental Engineering, University of Colorado Boulder

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: The science of how coronavirus drifts through the air in microscopic droplets.

from EarthSky https://ift.tt/3eWtAST

Aerosols are everywhere. Image via slobo/ E+ / Getty Images.

Shelly Miller, University of Colorado Boulder

During the 1970s when I was growing up in Southern California, the air was so polluted that I was regularly sent home from high school to “shelter in place.” There might not seem to be much in common between staying home due to air pollution and staying home to fight the coronavirus pandemic, but fundamentally, both have a lot to do with aerosols.

Aerosols are the tiny floating pieces of pollution that make up Los Angeles’ famous smog, the dust particles you see floating in a ray of sunshine and also the small droplets of liquid that escape your mouth when you talk, cough or breathe. These small pieces of floating liquids can contain pieces of the coronavirus and can be a major contributor to its spread.

If you walk outside right now, chances are you will see people wearing masks and practicing social distancing. These actions are in large part meant to prevent people from spreading or inhaling aerosols.

I am a professor of mechanical engineering and study aerosols and air pollution. The more people understand how aerosols work, the better people can avoid getting or spreading the coronavirus.

Airborne and everywhere

An aerosol is a clump of small liquid or solid particles floating in the air. They are everywhere in the environment and can be made of anything small enough to float, like smoke, water or coronavirus-carrying saliva.

When a person coughs, talks or breathes, they throw anywhere between 900 to 300,000 liquid particles from their mouth. These particles range in size from microscopic – a thousandth the width of a hair – up to the size of a grain of fine beach sand. A cough can send them traveling at speeds up to 60 mph.

From your lungs into the air around you, aerosols carry coronavirus. Image via Peter Dazeley/ The Image Bank/ Getty Images.

Size of the particle and air currents affect how long they will stay in the air. In a still room, tiny particles like smoke can stay airborne for up to eight hours. Larger particles fall out of the air more quickly and land on surfaces after a few minutes.

By simply being near other people, you are coming into constant contact with aerosols from their mouth. During a pandemic this a little more concerning than normal. But the important question is not do exhaled aerosols exist, rather, how infectious are they?

The coronavirus is small and easily transported by airborne particles of saliva. Image via fotograzia/ Moment/ Getty Images.

Aerosols as virus delivery systems

The new coronavirus, SARS-CoV-2, is tiny, about 0.1 microns – roughly 4 millionths of an inch – in diameter. Aerosols produced by people when they breathe, talk and cough are generally between about 0.7 microns to around 10 microns – completely invisible to the naked eye and easily able to float in air. These particles are mostly biological fluids from people’s mouths and lungs and can contain bits of virus genetic material.

Researchers don’t yet know how many individual pieces of SARS-CoV-2 an aerosol produced by an infected person’s cough might hold. But in one preprint study, meaning it is currently under peer review, researchers used a model to estimate that a person standing and speaking in a room could release up to 114 infectious doses per hour. The researchers predict that these aerosolized bits of saliva would easily infect other people if this happened in public indoor spaces like a bank, restaurant or pharmacy.

Another thing to consider is how easy these particles are to inhale. In a recent computer model study, researchers found that people would most likely inhale aerosols from another person that is talking and coughing while sitting less than 6 feet away.

While this seems bad, the actual process from exposure to infection is a complicated numbers game. Often, viral particles found in aerosols are damaged. A study looking at the flu virus found that only 0.1% of viruses exhaled by a person are actually infectious. The coronavirus also starts to die off once it has left the body, remaining viable in the air for up to 3 hours. And of course, not every aerosol coming from an infected person will contain the coronavirus. There is a lot of chance involved.

Public health officials still don’t know whether direct contact, indirect contact through surfaces, or aerosols are the main pathway of transmission for the coronavirus. But everything experts like myself know about aerosols suggests that they could be a major pathway of transmission.

Aerosol-driven outbreaks have been linked to restaurants, shops and many other public places. Image via AP Photo/ Vincent Yu.

Evidence of aerosol transmission

It is almost impossible to study viral transmission in real time, so researchers have turned to environmental sampling and contact tracing to try to study the spread of the coronavirus in aerosols. This research is happening extremely fast and most of it is still under peer review, but these studies offer extremely interesting, if preliminary, information.

To test the environment, researchers simply sample the air. In Nebraska, scientists found airborne SARS-CoV-2 in a hospital. In China, scientists also found the virus in the air of a number of hospitals as well as a department store.

But environmental sampling alone cannot prove aerosol transmission. That requires contact tracing.

One restaurant in Guangzhou, China, was the site of a small outbreak on January 23 and offers direct evidence of aerosol transmission. Researchers believe that there was one infected but asymptomatic person sitting at a table in the restaurant. Because of the air currents circulating in the room due to air conditioning, people sitting at two other tables became infected, likely because of aerosols.

Overall, the evidence suggests that it is much more risky to be inside than outside. The reason is the lack of airflow. It takes between 15 minutes and 3 hours for an aerosol to be sucked outside by a ventilation system or float out an open window.

Another preprint study of outbreaks in Japan suggests that the chances of direct transmission are almost 20 times higher indoors compared to outdoors. In Singapore, researchers traced the first 3 outbreaks directly to a few shops, a banquet dinner and a church.

Once outside, these potentially infectious aerosols disappear in the expanse of the atmosphere and are much less of a worry. It is, of course, possible to catch the virus outside if you are in close contact with a sick person, but this seems very rare. Researchers in China found that only 1 of 314 outbreaks they examined could be traced back to outdoor contact.

There has been recent concern over aerosol transmission during running and biking. While the science is still developing on this, it is probably wise to give other bikers or runners a little more room than normal.

Wearing masks and social distancing reduce the risk of spreading or inhaling aerosols. Image via AP Photo/ Gerald Herbert.

How to reduce aerosol transmission

With all of this knowledge of how aerosols are produced, how they move and the role they play in this pandemic, an obvious question arises: what about masks?

The Centers for Disease Control and Prevention recommends wearing a face mask in any public setting where social distancing is hard to do. This is because homemade masks probably do a reasonable job of blocking aerosols from leaving your mouth. The evidence generally supports their use and more research is coming to show that masks can be very effective at reducing SARS-CoV-2 in air. Masks aren’t perfect and more studies are currently underway to learn how effective they really are, but taking this small precaution could help slow the pandemic.

Other than wearing a mask, follow common sense and the guidance of public health officials. Avoid crowded indoor spaces as much as possible. Practice social distancing both inside and outdoors. Wash your hands frequently. All of these things work to prevent the spread of the coronavirus and can help keep you from getting it. There is a significant amount of evidence that Covid-19 is transmitted by the inhalation of airborne particles, but by carefully following the advice of experts, individuals can minimize the risk they pose.

Shelly Miller, Professor of Mechanical and Environmental Engineering, University of Colorado Boulder

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: The science of how coronavirus drifts through the air in microscopic droplets.

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Venus at its brightest in late April

Late April offers the planet Venus at its brightest in the evening sky for all of 2020, a glorious evening “star.” No matter where you live, look west after sunset for this bright planet. Venus is now nearly 3 times brighter than it was at its faintest some months ago. And that’s saying something, because Venus always ranks as the second-brightest heavenly body in the night sky (after the moon). It easily outshines all other planets and stars.

Venus will reach its greatest illuminated extent – when the lighted portion of the planet covers the greatest area of our sky’s dome – on April 28, 2020 at 01:00 Universal Time (April 27 at 8 p.m. CDT). It’s at or near greatest illuminated extent that Venus shines most brightly.

Venus’ reign in the evening sky started on August 14, 2019, and will come to an end on June 3, 2020. We know you might have seen Venus already. But watch for it these next several days, at dusk and early evening. Venus will dazzle you!

Chart by Guy Ottewell via his blog. The chart depicts Venus’ disk size and phase in the evening sky from superior conjunction (August 14, 2019) to inferior conjunction (June 3, 2020).

Did you know that Venus shows phases, just as the moon does? It might be hard to believe, but Venus shines at its brightest in our sky when displaying a crescent phase (approximately 25 percent illuminated). It’s as a crescent that Venus’ daytime side, or illuminated side, covers the maximum area of sky (greatest illuminated extent).

Although you need a telescope to view Venus’ disk and changing phases, the planet is always smallest (covers the smallest area of our sky’s dome) when Venus first enters the evening sky. That’s despite the fact that Venus is then at the full phase, just past superior conjunction or located across the solar system from us, just peeking out after being behind the sun as viewed from Earth. See the diagram at the bottom of this post. Superior conjunction last happened last August. Then Venus was on the far side of the sun from us, and farthest from Earth.

Superior conjunction – when Venus swept behind the sun from Earth – last happened on August 14, 2019. Just before and after that time, we saw a nearly full Venus. Inferior conjunction – when Venus will sweep between us and the sun – will happen next on June 3, 2020. Just before and after, we’ll see a crescent Venus. Image via UCLA.

Venus’ disk is largest when Venus leaves the evening sky some 292 days after superior conjunction. That’s how long it takes for Venus – in its smaller, faster orbit – to travel around in its orbit of the sun, until it sweeps between the sun and Earth at inferior conjunction. Then – phase-wise – Venus is at new phase.

When at inferior conjunction, the night side of Venus is facing Earth, and Venus is again lost in the sun’s glare. Thus we don’t see the planet (usually).

Inferior conjunction will next happen on June 3.

View larger at EarthSky Community Photos. | Did you think this was the moon? Aurelian Neacsu zoomed in on planet Venus from Visina, Romania, on April 24, 2020. Aurelian wrote: “The brightest planet during daytime … Phase 30%, 40 days before inferior conjunction.” Thank you, Aurelian.

This collection of Venus images from December 2016 to February 2017 shows how the size and phase of Venus changes as the planet nears its time of inferior conjunction, that is, its time of passing more or less between the sun and Earth. Image via our friend Tom Wildoner at the Dark Side Observatory.

Venus’ greatest illuminated extent in the evening sky – happening now – always happens about 36 days after Venus reaches greatest eastern (evening) elongation (in this case March 24, 2020), and some 36 days before Venus sweeps to inferior conjunction (June 3, 2020). At its greatest elongation, in either the evening or morning sky, Venus’ disk is approximately 50 percent covered over in sunshine.

On the other hand, Venus’ greatest illuminated extent in the morning sky (July 10, 2020) comes some 36 days after inferior conjunction (June 3, 2020) yet 36 days before reaching greatest western (morning) elongation (August 13, 2020). Isn’t it great how orderly the heavens are?

Let the golden triangle help you to remember these Venus’ milestones. The two base angles equal 72 degrees and the apex angle equals 36 degrees. Quite by coincidence, Venus’ greatest elongations happen some 72 days before and after inferior conjunction, and Venus’ greatest illuminated extent happens some 36 days before and after inferior conjunction.

Earth and Venus orbit the sun counterclockwise as seen from the north side of the solar system. Venus reaches its greatest eastern elongation in the evening sky about 72 days before inferior conjunction and its greatest western elongation in the morning sky about 72 days after inferior conjunction. Greatest illuminated extent for Venus comes midway between a greatest elongation and an inferior conjunction.

The Golden Triangle, with the apex angle = 36 degrees and base angles = 72 degrees

Bottom line: Look west after sunset in the days (and weeks) around April 27 and 28, 2020 to behold dazzling Venus, the sky’s brightest planet shining at her brightest best in the evening sky!

from EarthSky https://ift.tt/2KEP6O1

Late April offers the planet Venus at its brightest in the evening sky for all of 2020, a glorious evening “star.” No matter where you live, look west after sunset for this bright planet. Venus is now nearly 3 times brighter than it was at its faintest some months ago. And that’s saying something, because Venus always ranks as the second-brightest heavenly body in the night sky (after the moon). It easily outshines all other planets and stars.

Venus will reach its greatest illuminated extent – when the lighted portion of the planet covers the greatest area of our sky’s dome – on April 28, 2020 at 01:00 Universal Time (April 27 at 8 p.m. CDT). It’s at or near greatest illuminated extent that Venus shines most brightly.

Venus’ reign in the evening sky started on August 14, 2019, and will come to an end on June 3, 2020. We know you might have seen Venus already. But watch for it these next several days, at dusk and early evening. Venus will dazzle you!

Chart by Guy Ottewell via his blog. The chart depicts Venus’ disk size and phase in the evening sky from superior conjunction (August 14, 2019) to inferior conjunction (June 3, 2020).

Did you know that Venus shows phases, just as the moon does? It might be hard to believe, but Venus shines at its brightest in our sky when displaying a crescent phase (approximately 25 percent illuminated). It’s as a crescent that Venus’ daytime side, or illuminated side, covers the maximum area of sky (greatest illuminated extent).

Although you need a telescope to view Venus’ disk and changing phases, the planet is always smallest (covers the smallest area of our sky’s dome) when Venus first enters the evening sky. That’s despite the fact that Venus is then at the full phase, just past superior conjunction or located across the solar system from us, just peeking out after being behind the sun as viewed from Earth. See the diagram at the bottom of this post. Superior conjunction last happened last August. Then Venus was on the far side of the sun from us, and farthest from Earth.

Superior conjunction – when Venus swept behind the sun from Earth – last happened on August 14, 2019. Just before and after that time, we saw a nearly full Venus. Inferior conjunction – when Venus will sweep between us and the sun – will happen next on June 3, 2020. Just before and after, we’ll see a crescent Venus. Image via UCLA.

Venus’ disk is largest when Venus leaves the evening sky some 292 days after superior conjunction. That’s how long it takes for Venus – in its smaller, faster orbit – to travel around in its orbit of the sun, until it sweeps between the sun and Earth at inferior conjunction. Then – phase-wise – Venus is at new phase.

When at inferior conjunction, the night side of Venus is facing Earth, and Venus is again lost in the sun’s glare. Thus we don’t see the planet (usually).

Inferior conjunction will next happen on June 3.

View larger at EarthSky Community Photos. | Did you think this was the moon? Aurelian Neacsu zoomed in on planet Venus from Visina, Romania, on April 24, 2020. Aurelian wrote: “The brightest planet during daytime … Phase 30%, 40 days before inferior conjunction.” Thank you, Aurelian.

This collection of Venus images from December 2016 to February 2017 shows how the size and phase of Venus changes as the planet nears its time of inferior conjunction, that is, its time of passing more or less between the sun and Earth. Image via our friend Tom Wildoner at the Dark Side Observatory.

Venus’ greatest illuminated extent in the evening sky – happening now – always happens about 36 days after Venus reaches greatest eastern (evening) elongation (in this case March 24, 2020), and some 36 days before Venus sweeps to inferior conjunction (June 3, 2020). At its greatest elongation, in either the evening or morning sky, Venus’ disk is approximately 50 percent covered over in sunshine.

On the other hand, Venus’ greatest illuminated extent in the morning sky (July 10, 2020) comes some 36 days after inferior conjunction (June 3, 2020) yet 36 days before reaching greatest western (morning) elongation (August 13, 2020). Isn’t it great how orderly the heavens are?

Let the golden triangle help you to remember these Venus’ milestones. The two base angles equal 72 degrees and the apex angle equals 36 degrees. Quite by coincidence, Venus’ greatest elongations happen some 72 days before and after inferior conjunction, and Venus’ greatest illuminated extent happens some 36 days before and after inferior conjunction.

Earth and Venus orbit the sun counterclockwise as seen from the north side of the solar system. Venus reaches its greatest eastern elongation in the evening sky about 72 days before inferior conjunction and its greatest western elongation in the morning sky about 72 days after inferior conjunction. Greatest illuminated extent for Venus comes midway between a greatest elongation and an inferior conjunction.

The Golden Triangle, with the apex angle = 36 degrees and base angles = 72 degrees

Bottom line: Look west after sunset in the days (and weeks) around April 27 and 28, 2020 to behold dazzling Venus, the sky’s brightest planet shining at her brightest best in the evening sky!

from EarthSky https://ift.tt/2KEP6O1

Young moon and Venus: Favorite photos

View at EarthSky Community Photos. | Dr Ski in Valencia, Philippines captured this image during the day, at around 2:30 in the afternoon. He wrote: “The 3 day old crescent moon transits the meridian with Venus in tow. Finding Venus in the daytime is easier when the moon is nearby. The 9% crescent is 25 times brighter than Venus. They are 8° apart in this image.” Thank you, Dr Ski.

View at EarthSky Community Photos. | Frank Lu in Arlington, Texas caught thin clouds – and stars, the moon and a planet behind the clouds – in this 10-second exposure on April 25, 2020. He wrote: “The long exposure reveals a rush of clouds against the fixed universe, highlighted by the crescent Moon and Venus. Also clearly visible is the belt of Orion and various prominent stars.” Thank you, Frank.

View at EarthSky Community Photos. | Astrophotographer Riste Spiroski of the Ohrid Astronomy Association in Ohrid, North Macedonia said he caught the April 24, 2020 waxing crescent moon and Venus from his balcony. Thank you, Riste!

View at EarthSky Community Photos. | Fred Espenak captured the moon on April 24 and wrote: “The 2-day old crescent moon illuminated in Earthshine made a compelling sight as it set over Limestone Mountain (Portal, AZ). This time lapse captured the setting moon every 2.25 minutes.” Thank you, Fred.

Helio Vital in Rio de Janeiro, Brazil caught the very slender young moon in a bright twilight sky on April 24, 2020. Thank you, Helio.

View larger at EarthSky Community Photos. | Idriss Dhoparee caught the young moon from London, England, April 24, 2020. Idriss wrote: “Waxing crescent moon at 2.5% illumination. Rare catch considering the not so brilliant UK weather most of the time. We have had a long spell of sunshine. This moon in Islamic calender is the Ramadan, heralding a month of fasting.”

View larger at EarthSky Community Photos. | Chuck Reinhart in Vincennes, Indiana, caught the young crescent moon on April 24, 2020. He wrote: “Shortly after sunset I was able to photograph the crescent moon. I had to act fast as the clouds were rolling in.” Thanks, Chuck.

View larger at EarthSky Community Photos. | Mohamed Mohamed of Tripoli, Libya, captured the very young moon on April 24, 2020. Thanks, Mohamed!

View larger at EarthSky Community Photos. | Kevin Rundle caught the young moon and Venus from Santee, California on April 24, 2020, with an iPhone 7. Thanks, Kevin!

View larger at EarthSky Community Photos. | Peter Lowenstein caught the young moon and bright Venus from Mutare, Zimbabwe, on April 24, 2020. He wrote: “Venus and Aldebaran (top) with the Pleiades and Young Moon setting below at 6.15 pm. On Friday evening clear visibility and a cloudless sky promised to provide a perfect view of the Young Crescent Moon (only 18 hours old) setting below the local horizon to the north of Christmas Pass. However sunset at a quarter past five was followed by the development of a large sunset stratospheric aerosol twilight arch which was so bright that it prevented the thin young Moon from becoming clearly visible to the naked eye for almost three quarters of an hour. This left only twenty minutes to watch it setting. Just before it did I managed to capture this splendid image with planet Venus, stars and young moon present.” Thanks, Peter!

View larger at EarthSky Community Photos. | This is not the moon! Aurelian Neacsu zoomed in on the crescent planet Venus from Visina, Romania, on April 24. Aurelian wrote: “The brightest planet during daytime … Phase: 30%, 40 days before inferior conjunction.” Thanks, Aurelian.

Bottom line: The moon is sweeping past Venus on these late April 2020 evenings. The EarthSky Community is catching them, and sharing their photos. Thanks to all who submitted.

from EarthSky https://ift.tt/2W1EyNY

View at EarthSky Community Photos. | Dr Ski in Valencia, Philippines captured this image during the day, at around 2:30 in the afternoon. He wrote: “The 3 day old crescent moon transits the meridian with Venus in tow. Finding Venus in the daytime is easier when the moon is nearby. The 9% crescent is 25 times brighter than Venus. They are 8° apart in this image.” Thank you, Dr Ski.

View at EarthSky Community Photos. | Frank Lu in Arlington, Texas caught thin clouds – and stars, the moon and a planet behind the clouds – in this 10-second exposure on April 25, 2020. He wrote: “The long exposure reveals a rush of clouds against the fixed universe, highlighted by the crescent Moon and Venus. Also clearly visible is the belt of Orion and various prominent stars.” Thank you, Frank.

View at EarthSky Community Photos. | Astrophotographer Riste Spiroski of the Ohrid Astronomy Association in Ohrid, North Macedonia said he caught the April 24, 2020 waxing crescent moon and Venus from his balcony. Thank you, Riste!

View at EarthSky Community Photos. | Fred Espenak captured the moon on April 24 and wrote: “The 2-day old crescent moon illuminated in Earthshine made a compelling sight as it set over Limestone Mountain (Portal, AZ). This time lapse captured the setting moon every 2.25 minutes.” Thank you, Fred.

Helio Vital in Rio de Janeiro, Brazil caught the very slender young moon in a bright twilight sky on April 24, 2020. Thank you, Helio.

View larger at EarthSky Community Photos. | Idriss Dhoparee caught the young moon from London, England, April 24, 2020. Idriss wrote: “Waxing crescent moon at 2.5% illumination. Rare catch considering the not so brilliant UK weather most of the time. We have had a long spell of sunshine. This moon in Islamic calender is the Ramadan, heralding a month of fasting.”

View larger at EarthSky Community Photos. | Chuck Reinhart in Vincennes, Indiana, caught the young crescent moon on April 24, 2020. He wrote: “Shortly after sunset I was able to photograph the crescent moon. I had to act fast as the clouds were rolling in.” Thanks, Chuck.

View larger at EarthSky Community Photos. | Mohamed Mohamed of Tripoli, Libya, captured the very young moon on April 24, 2020. Thanks, Mohamed!

View larger at EarthSky Community Photos. | Kevin Rundle caught the young moon and Venus from Santee, California on April 24, 2020, with an iPhone 7. Thanks, Kevin!

View larger at EarthSky Community Photos. | Peter Lowenstein caught the young moon and bright Venus from Mutare, Zimbabwe, on April 24, 2020. He wrote: “Venus and Aldebaran (top) with the Pleiades and Young Moon setting below at 6.15 pm. On Friday evening clear visibility and a cloudless sky promised to provide a perfect view of the Young Crescent Moon (only 18 hours old) setting below the local horizon to the north of Christmas Pass. However sunset at a quarter past five was followed by the development of a large sunset stratospheric aerosol twilight arch which was so bright that it prevented the thin young Moon from becoming clearly visible to the naked eye for almost three quarters of an hour. This left only twenty minutes to watch it setting. Just before it did I managed to capture this splendid image with planet Venus, stars and young moon present.” Thanks, Peter!

View larger at EarthSky Community Photos. | This is not the moon! Aurelian Neacsu zoomed in on the crescent planet Venus from Visina, Romania, on April 24. Aurelian wrote: “The brightest planet during daytime … Phase: 30%, 40 days before inferior conjunction.” Thanks, Aurelian.

Bottom line: The moon is sweeping past Venus on these late April 2020 evenings. The EarthSky Community is catching them, and sharing their photos. Thanks to all who submitted.

from EarthSky https://ift.tt/2W1EyNY