Stunning images of the night

View larger | Mihail Minkov captured this photo, which is titled Star Catcher. The photo is from the Black Sea Coast of Bulgaria. It’s the 1st-place winner in 2020’s IDA photo contest, in the Connecting to the Dark category.

The International Dark-Sky Association (IDA) held its first annual Capture the Dark photography competition during May 2020. The goal was to portray the meaning of the night for people around the world. Participants were invited to submit images in five categories: Connecting to the Dark, International Dark Sky Places, Impact of Light Pollution, Bright Side of Lighting, and Youth. In two weeks, IDA received nearly 450 submissions from people around the world. An international panel of judges made the final selections. The winning entries in each category are on this page.

See all winners’ and finalists’ photos here.

Category 1: Connecting to the Dark.

IDA explained:

Experiencing a natural night provides perspective, inspiration, and leads us to reflect on our humanity and place in the universe.

The winning entry in this category is Star Catcher, shown at the top of this post. Photographer Mihail Minkov said:

I have a 4-year-old daughter, who is really in love with the night sky … She is always asking to come with me when I go to shoot the Milky Way. So I decided to make her part of the process and try to show her what it’s like to be out under the dark sky, and see the beauty of the night sky. I hope that one day, she will remember that, and this memory will make her a good and decent person, who really takes care of the planet and the night sky.

View larger. | Jean-Francois Graffand captured this image at the Pic du Midi International Dark Sky Reserve in France. It’s the winner in the International Dark Sky Places category. The photo is titled Dark Night in Pyrénées Mountains.

Category 2: International Dark Sky Places.

IDA explained:

Over 130 protected lands and municipalities have been certified by IDA as an International Dark Sky Place creating havens for astrophotographers around the world.

Winning photographer Jean-Francois Graffand said:

A typical landscape of French Pyrénées mountains, taken inside the Pic du Midi Dark Sky Reserve, during a summer night. At 1,400-meters [4,600 feet] of altitude, the mountain torrent descends into the valley where absolutely no source of light is visible at night.

View larger. | Petr Horálek captured this image at the Great Wall of China. It’s the winner in the Impact of Light Pollution category. The photo is titled Remembering the Old Times.

Category 3: Impact of Light Pollution.

IDA explained:

Light pollution can have significant impacts on the environment, human health, and our access to the universe.

Winning photographer Petr Horálek said:

Stargazing on one of the most legendary ancient human creations, the Chinese Great Wall, makes you deeply think. A piece of deepest history meets current civilization, unfortunately producing the light pollution. Think about how wonderful skies looked for ancient Chinese people walking the wall.

View larger. | Jean-Francois Graffand captured this photo at the Pyrénées National Parc in France. It’s the winner in the Bright Side of Lighting category. It’s titled The Celestial River.

Category 4: Bright Side of Lighting.

IDA explained:

Light pollution can give lighting a bad rap. But lighting that follows IDA’s Principles for Responsible Outdoor Light can be beautiful, healthy, and functional.

Winning photographer Jean-Francois Graffand said:

Panoramic view of the Pont d’Espagne site, in the heart of the Pic du Midi Dark Sky Reserve … Surrounded by the mountains at 1500m [5,000 ft] of altitude, all the city lights in the valley are hidden. During the summer tourist season, the little restaurant hosts some employees, which can generate the only light source. Here only a faint warm bedside lamp is turned on in a room, but amplified by the long exposure and high iso, it seems to light up the place like a beacon and reveals the landscape.

View larger.| Nayana Rajesh, age 16, captured the winning entry in the Youth category. The photo is set in Ennis, Texas. It’s titled “The Barn.”

Category 5: Youth.

IDA explained:

Entrant must be 17 years old or younger.

Winning photographer Nayana Rajesh said:

One of my favorite things about living in Texas is the blooming of the bluebonnets each year. I went out to Ennis, Texas, to shoot the bluebonnets under the stars at a ranch owned by our friend Jim. It’s important to me to always be learning something new every time I shoot, so I spent the night learning how to focus stack manually and think through different compositions.

See all winners’ and finalists’ photos here.

Bottom line: Winning photos in the International Dark-Sky Association (IDA) 2020 photography contest.

Via International Dark-Sky Association

See all winners’ and finalists’ photos here.

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

View larger | Mihail Minkov captured this photo, which is titled Star Catcher. The photo is from the Black Sea Coast of Bulgaria. It’s the 1st-place winner in 2020’s IDA photo contest, in the Connecting to the Dark category.

The International Dark-Sky Association (IDA) held its first annual Capture the Dark photography competition during May 2020. The goal was to portray the meaning of the night for people around the world. Participants were invited to submit images in five categories: Connecting to the Dark, International Dark Sky Places, Impact of Light Pollution, Bright Side of Lighting, and Youth. In two weeks, IDA received nearly 450 submissions from people around the world. An international panel of judges made the final selections. The winning entries in each category are on this page.

See all winners’ and finalists’ photos here.

Category 1: Connecting to the Dark.

IDA explained:

Experiencing a natural night provides perspective, inspiration, and leads us to reflect on our humanity and place in the universe.

The winning entry in this category is Star Catcher, shown at the top of this post. Photographer Mihail Minkov said:

I have a 4-year-old daughter, who is really in love with the night sky … She is always asking to come with me when I go to shoot the Milky Way. So I decided to make her part of the process and try to show her what it’s like to be out under the dark sky, and see the beauty of the night sky. I hope that one day, she will remember that, and this memory will make her a good and decent person, who really takes care of the planet and the night sky.

View larger. | Jean-Francois Graffand captured this image at the Pic du Midi International Dark Sky Reserve in France. It’s the winner in the International Dark Sky Places category. The photo is titled Dark Night in Pyrénées Mountains.

Category 2: International Dark Sky Places.

IDA explained:

Over 130 protected lands and municipalities have been certified by IDA as an International Dark Sky Place creating havens for astrophotographers around the world.

Winning photographer Jean-Francois Graffand said:

A typical landscape of French Pyrénées mountains, taken inside the Pic du Midi Dark Sky Reserve, during a summer night. At 1,400-meters [4,600 feet] of altitude, the mountain torrent descends into the valley where absolutely no source of light is visible at night.

View larger. | Petr Horálek captured this image at the Great Wall of China. It’s the winner in the Impact of Light Pollution category. The photo is titled Remembering the Old Times.

Category 3: Impact of Light Pollution.

IDA explained:

Light pollution can have significant impacts on the environment, human health, and our access to the universe.

Winning photographer Petr Horálek said:

Stargazing on one of the most legendary ancient human creations, the Chinese Great Wall, makes you deeply think. A piece of deepest history meets current civilization, unfortunately producing the light pollution. Think about how wonderful skies looked for ancient Chinese people walking the wall.

View larger. | Jean-Francois Graffand captured this photo at the Pyrénées National Parc in France. It’s the winner in the Bright Side of Lighting category. It’s titled The Celestial River.

Category 4: Bright Side of Lighting.

IDA explained:

Light pollution can give lighting a bad rap. But lighting that follows IDA’s Principles for Responsible Outdoor Light can be beautiful, healthy, and functional.

Winning photographer Jean-Francois Graffand said:

Panoramic view of the Pont d’Espagne site, in the heart of the Pic du Midi Dark Sky Reserve … Surrounded by the mountains at 1500m [5,000 ft] of altitude, all the city lights in the valley are hidden. During the summer tourist season, the little restaurant hosts some employees, which can generate the only light source. Here only a faint warm bedside lamp is turned on in a room, but amplified by the long exposure and high iso, it seems to light up the place like a beacon and reveals the landscape.

View larger.| Nayana Rajesh, age 16, captured the winning entry in the Youth category. The photo is set in Ennis, Texas. It’s titled “The Barn.”

Category 5: Youth.

IDA explained:

Entrant must be 17 years old or younger.

Winning photographer Nayana Rajesh said:

One of my favorite things about living in Texas is the blooming of the bluebonnets each year. I went out to Ennis, Texas, to shoot the bluebonnets under the stars at a ranch owned by our friend Jim. It’s important to me to always be learning something new every time I shoot, so I spent the night learning how to focus stack manually and think through different compositions.

See all winners’ and finalists’ photos here.

Bottom line: Winning photos in the International Dark-Sky Association (IDA) 2020 photography contest.

Via International Dark-Sky Association

See all winners’ and finalists’ photos here.

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

Astronomers discover 6 possible new exomoons

Artist’s concept of a habitable exomoon orbiting a distant exoplanet similar to Saturn. Astronomers have now discovered what may be 6 more exomoons orbiting exoplanets ranging from 200 to 3,000 light-years away. There are hundreds of moons in our own solar system, and some of them have subsurface water oceans. How many similar ocean moons may be out there? Image via SpaceRef/ Astrobiology Web.

Our solar system is filled with hundreds of moons, many more moons than planets. But what about distant solar systems? We now know of well over 4,000 confirmed exoplanets – or planets orbiting distant stars – 4,171 right now, to be exact. Yet there’ve been, so far, still only a few possible detections of exomoons. It makes sense, given that moons of planets tend to be smaller and thus more difficult to find than planets themselves. But now scientists at Western University in London, Ontario, Canada, have announced that they might have spotted six more exomoons!

The potentially exciting findings have been submitted in a new paper to the Monthly Notices of the Royal Astronomical Society, with a preprint version posted on arXiv on June 23, 2020.

The possible moons are not confirmed yet, but the results seem promising. As Paul Wiegert, co-author of the study, noted in a statement:

We know of thousands of exoplanets throughout our Milky Way galaxy, but we know of only a handful of exomoon candidates.

From the paper:

Here we explore eight systems from the Kepler data set to examine the exomoon hypothesis as an explanation for their transit timing variations, which we compare with the alternate hypothesis that the TTVs are caused by an non-transiting planet in the system. We find that the TTVs of six of these systems could be plausibly explained by an exomoon, the size of which would not be nominally detectable by Kepler. Though we also find that the TTVs could be equally well reproduced by the presence of a non-transiting planet in the system, the observations are nevertheless completely consistent with a existence of a dynamically stable moon small enough to fall below Kepler’s photometric threshold for transit detection, and these systems warrant further observation and analysis.

So where are these moons and how were they potentially found?

The moons are in data from the Kepler Space Telescope mission, which ended in 2018. The host planets range from about 200 to 3,000 light-years away, and were discovered by the transits that the planets made in front of their stars, which caused the star’s brightness to dim slightly and briefly. Most exoplanets are found using the transit method. But the moons are much smaller and dimmer, so they are very difficult to detect by any method. Wiegert said:

These exomoon candidates are so small that they can’t be seen from their own transits. Rather, their presence is given away by their gravitational influence on their parent planet.

The six moon candidates are (KOI) 268.01, Kepler 517b (KOI-303.01), Kepler 1000b (KOI-1888.01), Kepler 409b (KOI-1925.01), Kepler 1326b (KOI-2728.01) and Kepler 1442b (KOI-3220.01). KOI refers to Kepler Object of Interest.

So how might these moons reveal themselves?

Usually, the transit of a planet occurs precisely at regular timed intervals, the same as how planets orbit our own sun. But sometimes, that precise timing is actually variable. This means that the gravity of some other body, another planet or a moon, must be affecting it. These variations are called transit timing variations (TTVs). The results fit with what would be expected of exomoons, but could still possibly be explained by other planets in these systems instead. As Fox explained:

Because exoplanets are more massive than exomoons, most TTVs observed to date have been linked to the influence of other exoplanets. But now we’ve uncovered six Kepler exoplanet systems whose TTVs are equally well explained by exomoons as by exoplanets. That’s why we’re calling them exomoon ‘candidates’ at this point as they still need follow-up confirmation.

TTVs were also found for two other exoplanets, KOI-1503.01 and KOI-1980.01, but those are thought to be caused by other planets in the systems instead of moons and were ruled out.

Artist’s concept of the possible huge exomoon orbiting the exoplanet Kepler-1625b, found by the Hubble Space Telescope in 2018. Image via HubbleSite.

That confirmation may have to wait a while, however, since current telescopes can’t do it; it will require telescopes that are being planned and designed, but not built yet. Fox said:

We can say these six new systems are completely consistent with exomoons: their masses and orbits are such that they would be stable; they would be small enough that their own transits wouldn’t be seen; and they reproduce the pattern of TTVs seen throughout the entire Kepler data set. But we don’t have the technology to confirm them by imaging them directly. That will have to wait for further advancements.

It is exciting to contemplate what kinds of alien exomoons are out there. Just in our own solar system, there is a huge variety of these smaller worlds, from gray, cratered and moon-like, to Io, which kind of looks like a pizza and has the most active volcanoes of any object in the solar system, to ocean worlds like Europa, Enceladus and others. The icy moons with subsurface oceans are especially appealing, since they could be habitable by earthly standards. There are several of them in our solar system alone, so how many more might be out there? What kind of life might exist on such worlds? Chris Fox, who made the discoveries, said:

Our own solar system contains hundreds of moons. If moons are prolific around other stars, too, it greatly increases the potential places where life might be supported, and where humankind might one day venture.

Chris Fox at Western University, who discovered the possible new exomoons. Image via CBC.

Fox makes a very good point. Since our own solar system has hundreds of moons orbiting six out of the eight planets, is it not reasonable that many of the planets in other solar systems would also have their own moons? And as we are now discovering, a good number of the moons in our solar system are indeed potentially habitable, with their subsurface water oceans.

In 2018, Fox also discovered Kepler-159d, an exoplanet about the size of Saturn, which orbits its star in only 88 days.

In 2014, another possible exomoon, dubbed MOA-2011-BLG-262 exoplanet-exomoon system, was discovered, where the moon would be less massive than Earth and the planet would be more massive than Jupiter. In 2018, the Hubble Space Telescope (HST) found what may be a huge exomoon orbiting the gas giant planet Kepler-1625b. It’s also still not confirmed yet, but if real, is about the size of Neptune! If the new findings from Western University are any indication – and confirmed – then there may many more exomoon discoveries to look forward to.

Bottom line: Astronomers examining data from the Kepler Space Telescope appear to have discovered six more exomoons. Although the result awaits confirmation, it has the potential to be a big step forward in understanding distant solar systems.

Source: Exomoon Candidates from Transit Timing Variations: Six Kepler systems with TTVs explainable by photometrically unseen exomoons

Via Western News

from EarthSky https://ift.tt/2ZvIc4z

Artist’s concept of a habitable exomoon orbiting a distant exoplanet similar to Saturn. Astronomers have now discovered what may be 6 more exomoons orbiting exoplanets ranging from 200 to 3,000 light-years away. There are hundreds of moons in our own solar system, and some of them have subsurface water oceans. How many similar ocean moons may be out there? Image via SpaceRef/ Astrobiology Web.

Our solar system is filled with hundreds of moons, many more moons than planets. But what about distant solar systems? We now know of well over 4,000 confirmed exoplanets – or planets orbiting distant stars – 4,171 right now, to be exact. Yet there’ve been, so far, still only a few possible detections of exomoons. It makes sense, given that moons of planets tend to be smaller and thus more difficult to find than planets themselves. But now scientists at Western University in London, Ontario, Canada, have announced that they might have spotted six more exomoons!

The potentially exciting findings have been submitted in a new paper to the Monthly Notices of the Royal Astronomical Society, with a preprint version posted on arXiv on June 23, 2020.

The possible moons are not confirmed yet, but the results seem promising. As Paul Wiegert, co-author of the study, noted in a statement:

We know of thousands of exoplanets throughout our Milky Way galaxy, but we know of only a handful of exomoon candidates.

From the paper:

Here we explore eight systems from the Kepler data set to examine the exomoon hypothesis as an explanation for their transit timing variations, which we compare with the alternate hypothesis that the TTVs are caused by an non-transiting planet in the system. We find that the TTVs of six of these systems could be plausibly explained by an exomoon, the size of which would not be nominally detectable by Kepler. Though we also find that the TTVs could be equally well reproduced by the presence of a non-transiting planet in the system, the observations are nevertheless completely consistent with a existence of a dynamically stable moon small enough to fall below Kepler’s photometric threshold for transit detection, and these systems warrant further observation and analysis.

So where are these moons and how were they potentially found?

The moons are in data from the Kepler Space Telescope mission, which ended in 2018. The host planets range from about 200 to 3,000 light-years away, and were discovered by the transits that the planets made in front of their stars, which caused the star’s brightness to dim slightly and briefly. Most exoplanets are found using the transit method. But the moons are much smaller and dimmer, so they are very difficult to detect by any method. Wiegert said:

These exomoon candidates are so small that they can’t be seen from their own transits. Rather, their presence is given away by their gravitational influence on their parent planet.

The six moon candidates are (KOI) 268.01, Kepler 517b (KOI-303.01), Kepler 1000b (KOI-1888.01), Kepler 409b (KOI-1925.01), Kepler 1326b (KOI-2728.01) and Kepler 1442b (KOI-3220.01). KOI refers to Kepler Object of Interest.

So how might these moons reveal themselves?

Usually, the transit of a planet occurs precisely at regular timed intervals, the same as how planets orbit our own sun. But sometimes, that precise timing is actually variable. This means that the gravity of some other body, another planet or a moon, must be affecting it. These variations are called transit timing variations (TTVs). The results fit with what would be expected of exomoons, but could still possibly be explained by other planets in these systems instead. As Fox explained:

Because exoplanets are more massive than exomoons, most TTVs observed to date have been linked to the influence of other exoplanets. But now we’ve uncovered six Kepler exoplanet systems whose TTVs are equally well explained by exomoons as by exoplanets. That’s why we’re calling them exomoon ‘candidates’ at this point as they still need follow-up confirmation.

TTVs were also found for two other exoplanets, KOI-1503.01 and KOI-1980.01, but those are thought to be caused by other planets in the systems instead of moons and were ruled out.

Artist’s concept of the possible huge exomoon orbiting the exoplanet Kepler-1625b, found by the Hubble Space Telescope in 2018. Image via HubbleSite.

That confirmation may have to wait a while, however, since current telescopes can’t do it; it will require telescopes that are being planned and designed, but not built yet. Fox said:

We can say these six new systems are completely consistent with exomoons: their masses and orbits are such that they would be stable; they would be small enough that their own transits wouldn’t be seen; and they reproduce the pattern of TTVs seen throughout the entire Kepler data set. But we don’t have the technology to confirm them by imaging them directly. That will have to wait for further advancements.

It is exciting to contemplate what kinds of alien exomoons are out there. Just in our own solar system, there is a huge variety of these smaller worlds, from gray, cratered and moon-like, to Io, which kind of looks like a pizza and has the most active volcanoes of any object in the solar system, to ocean worlds like Europa, Enceladus and others. The icy moons with subsurface oceans are especially appealing, since they could be habitable by earthly standards. There are several of them in our solar system alone, so how many more might be out there? What kind of life might exist on such worlds? Chris Fox, who made the discoveries, said:

Our own solar system contains hundreds of moons. If moons are prolific around other stars, too, it greatly increases the potential places where life might be supported, and where humankind might one day venture.

Chris Fox at Western University, who discovered the possible new exomoons. Image via CBC.

Fox makes a very good point. Since our own solar system has hundreds of moons orbiting six out of the eight planets, is it not reasonable that many of the planets in other solar systems would also have their own moons? And as we are now discovering, a good number of the moons in our solar system are indeed potentially habitable, with their subsurface water oceans.

In 2018, Fox also discovered Kepler-159d, an exoplanet about the size of Saturn, which orbits its star in only 88 days.

In 2014, another possible exomoon, dubbed MOA-2011-BLG-262 exoplanet-exomoon system, was discovered, where the moon would be less massive than Earth and the planet would be more massive than Jupiter. In 2018, the Hubble Space Telescope (HST) found what may be a huge exomoon orbiting the gas giant planet Kepler-1625b. It’s also still not confirmed yet, but if real, is about the size of Neptune! If the new findings from Western University are any indication – and confirmed – then there may many more exomoon discoveries to look forward to.

Bottom line: Astronomers examining data from the Kepler Space Telescope appear to have discovered six more exomoons. Although the result awaits confirmation, it has the potential to be a big step forward in understanding distant solar systems.

Source: Exomoon Candidates from Transit Timing Variations: Six Kepler systems with TTVs explainable by photometrically unseen exomoons

Via Western News

from EarthSky https://ift.tt/2ZvIc4z

At least 2 super-Earths orbit this red dwarf star

Artist’s concept of Gliese 887b and Gliese 887c orbiting their red dwarf star. Image via Mark Garlick/ University of Göttingen.

Among the various types of exoplanets discovered so far, those larger than Earth but smaller than Neptune are among the most common. Astronomers call these worlds super-Earths. The nearby TRAPPIST-1 planetary system actually has seven known super-Earths orbiting its star! Now, RedDots researchers at the University of Göttingen in Germany have announced the discovery of another nearby planetary system with at least two super-Earths and possibly a third.

Details of the peer-reviewed findings have been published in the June 26, 2020, issue of the journal Science.

The two planets are orbiting the nearby red dwarf star called Gliese 887 (also known as GJ 887 or Lacaille 9352), which is only 11 light-years away. While not quite within the habitable zone, where liquid water could exist on the surface of rocky worlds, the planets are close to the inner edge of the zone. According to the abstract of the new paper:

The closest exoplanets to the sun provide opportunities for detailed characterization of planets outside the solar system. We report the discovery, using radial velocity measurements, of a compact multiplanet system of super-Earth exoplanets orbiting the nearby red dwarf star GJ 887. The two planets have orbital periods of 9.3 and 21.8 days. Assuming an Earth-like albedo, the equilibrium temperature of the 21.8-day planet is ~350 kelvin [-623 Celsius or -1,090 Fahrenheit]. The planets are interior to, but close to the inner edge of, the liquid-water habitable zone. We also detect an unconfirmed signal with a period of ~50 days, which could correspond to a third super-Earth in a more temperate orbit. Our observations show that GJ 887 has photometric variability below 500 parts per million, which is unusually quiet for a red dwarf.

Illustration depicting the size of a super-Earth called CoRoT-7b. Super-Earths are larger and more massive than Earth, but smaller and less massive than Neptune. Image via Aldaron/ Wikipedia.

Super-Earths are one of the most common types of planets in our galaxy. Some of them may be habitable for some kind of life to exist. Image via NASA/ JPL-Caltech/ R. Hurt (SSC-Caltech)/ Earth Magazine.

The temperature of Gliese 887c has been estimated at 158 degrees Fahrenheit (70 degrees Celsius). A bit hot, but perhaps not enough to render the planet uninhabitable. If the third planet does exist, it could have cooler temperatures since it is in a more temperate orbit within the habitable zone.

The planets were discovered using the “Doppler Wobble” technique, which enables the researchers to measure the tiny back and forth wobbles of the star caused by the gravitational pull of the planets. The researchers used the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph at the European Southern Observatory (ESO) in Chile.

Red dwarf stars, although smaller and dimmer than our sun, are known for typically being very active, emitting strong bursts of radiation that could strip close-in planets of their atmospheres and make conditions difficult or impossible for life to exist. But Gliese 887 has only a very few star spots and appears to be less active than most red dwarfs. That’s good news for the possibility of any of the planets retaining their atmospheres and perhaps being habitable.

In a related Perspective article, Melvyn Davies wrote:

If someone had to live around a red dwarf, they would want to choose a quieter star like GJ 887. If further observations confirm the presence of the third planet in the habitable zone, then GJ 887 could become one of the most studied planetary systems in the solar neighborhood.

Red dwarf stars are known for being very active, emitting powerful blasts of solar radiation, which can strip atmospheres off planets that are too close, as in this artist’s concept. But Gliese 887 is less active than most red dwarfs, increasing the chance that some of its planets might be potentially habitable. Image via NASA/ Ames/ JPL-Caltech/ HowStuffWorks.

The Gliese 887 worlds will also be ideal candidates for follow-up studies by the upcoming James Webb Space Telescope (JWST), not only because they are close by, but also because the brightness of the star is almost constant, making it easier to detect any atmospheres. As Sandra Jeffers, from the University of Göttingen and lead author of the study, said in a statement:

These planets will provide the best possibilities for more detailed studies, including the search for life outside our solar system.

The discovery reinforces two previous findings about exoplanets: one, super-Earth worlds are common (as well as Earth-sized planets), even though there isn’t one in our solar system (unless the elusive Planet Nine turns out to be one, as some scientists think), and two, exoplanets are abundant around red dwarf stars, which are the most common stars in our galaxy. This is exciting, since many, if not most, super-Earths are thought to be rocky like our own planet. But we still don’t know how habitable these kinds of worlds could be. Scientists think that some super-Earths could have extensive or even global oceans. Others might be dry and barren.

Sandra Jeffers at the University of Göttingen in Germany, lead author of the new study. Image via University of Göttingen.

New upcoming telescopes like JWST will be able to take a closer look at some of these worlds, and provide a much better idea of what the actual conditions are like. If there are millions or billions of them in our galaxy, as seems likely – and scientists now say there are more exoplanets in total than stars, including an estimated six billion ‘Earth-like’ planets – then it seems reasonable that some of them should be potentially habitable.

Bottom line: Astronomers have discovered two, and possibly three, super-Earth exoplanets orbiting a nearby red dwarf star.

Source: A multiplanet system of super-Earths orbiting the brightest red dwarf star GJ 887

Via University of Göttingen

Via EurekAlert!

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

Artist’s concept of Gliese 887b and Gliese 887c orbiting their red dwarf star. Image via Mark Garlick/ University of Göttingen.

Among the various types of exoplanets discovered so far, those larger than Earth but smaller than Neptune are among the most common. Astronomers call these worlds super-Earths. The nearby TRAPPIST-1 planetary system actually has seven known super-Earths orbiting its star! Now, RedDots researchers at the University of Göttingen in Germany have announced the discovery of another nearby planetary system with at least two super-Earths and possibly a third.

Details of the peer-reviewed findings have been published in the June 26, 2020, issue of the journal Science.

The two planets are orbiting the nearby red dwarf star called Gliese 887 (also known as GJ 887 or Lacaille 9352), which is only 11 light-years away. While not quite within the habitable zone, where liquid water could exist on the surface of rocky worlds, the planets are close to the inner edge of the zone. According to the abstract of the new paper:

The closest exoplanets to the sun provide opportunities for detailed characterization of planets outside the solar system. We report the discovery, using radial velocity measurements, of a compact multiplanet system of super-Earth exoplanets orbiting the nearby red dwarf star GJ 887. The two planets have orbital periods of 9.3 and 21.8 days. Assuming an Earth-like albedo, the equilibrium temperature of the 21.8-day planet is ~350 kelvin [-623 Celsius or -1,090 Fahrenheit]. The planets are interior to, but close to the inner edge of, the liquid-water habitable zone. We also detect an unconfirmed signal with a period of ~50 days, which could correspond to a third super-Earth in a more temperate orbit. Our observations show that GJ 887 has photometric variability below 500 parts per million, which is unusually quiet for a red dwarf.

Illustration depicting the size of a super-Earth called CoRoT-7b. Super-Earths are larger and more massive than Earth, but smaller and less massive than Neptune. Image via Aldaron/ Wikipedia.

Super-Earths are one of the most common types of planets in our galaxy. Some of them may be habitable for some kind of life to exist. Image via NASA/ JPL-Caltech/ R. Hurt (SSC-Caltech)/ Earth Magazine.

The temperature of Gliese 887c has been estimated at 158 degrees Fahrenheit (70 degrees Celsius). A bit hot, but perhaps not enough to render the planet uninhabitable. If the third planet does exist, it could have cooler temperatures since it is in a more temperate orbit within the habitable zone.

The planets were discovered using the “Doppler Wobble” technique, which enables the researchers to measure the tiny back and forth wobbles of the star caused by the gravitational pull of the planets. The researchers used the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph at the European Southern Observatory (ESO) in Chile.

Red dwarf stars, although smaller and dimmer than our sun, are known for typically being very active, emitting strong bursts of radiation that could strip close-in planets of their atmospheres and make conditions difficult or impossible for life to exist. But Gliese 887 has only a very few star spots and appears to be less active than most red dwarfs. That’s good news for the possibility of any of the planets retaining their atmospheres and perhaps being habitable.

In a related Perspective article, Melvyn Davies wrote:

If someone had to live around a red dwarf, they would want to choose a quieter star like GJ 887. If further observations confirm the presence of the third planet in the habitable zone, then GJ 887 could become one of the most studied planetary systems in the solar neighborhood.

Red dwarf stars are known for being very active, emitting powerful blasts of solar radiation, which can strip atmospheres off planets that are too close, as in this artist’s concept. But Gliese 887 is less active than most red dwarfs, increasing the chance that some of its planets might be potentially habitable. Image via NASA/ Ames/ JPL-Caltech/ HowStuffWorks.

The Gliese 887 worlds will also be ideal candidates for follow-up studies by the upcoming James Webb Space Telescope (JWST), not only because they are close by, but also because the brightness of the star is almost constant, making it easier to detect any atmospheres. As Sandra Jeffers, from the University of Göttingen and lead author of the study, said in a statement:

These planets will provide the best possibilities for more detailed studies, including the search for life outside our solar system.

The discovery reinforces two previous findings about exoplanets: one, super-Earth worlds are common (as well as Earth-sized planets), even though there isn’t one in our solar system (unless the elusive Planet Nine turns out to be one, as some scientists think), and two, exoplanets are abundant around red dwarf stars, which are the most common stars in our galaxy. This is exciting, since many, if not most, super-Earths are thought to be rocky like our own planet. But we still don’t know how habitable these kinds of worlds could be. Scientists think that some super-Earths could have extensive or even global oceans. Others might be dry and barren.

Sandra Jeffers at the University of Göttingen in Germany, lead author of the new study. Image via University of Göttingen.

New upcoming telescopes like JWST will be able to take a closer look at some of these worlds, and provide a much better idea of what the actual conditions are like. If there are millions or billions of them in our galaxy, as seems likely – and scientists now say there are more exoplanets in total than stars, including an estimated six billion ‘Earth-like’ planets – then it seems reasonable that some of them should be potentially habitable.

Bottom line: Astronomers have discovered two, and possibly three, super-Earth exoplanets orbiting a nearby red dwarf star.

Source: A multiplanet system of super-Earths orbiting the brightest red dwarf star GJ 887

Via University of Göttingen

Via EurekAlert!

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

World Zoonoses Day: 'We have to act now to avoid even bigger catastrophes'

"The primary risks for future spillover of zoonotic diseases are deforestation of tropical environments and large-scale industrial farming of animals, specifically pigs and chickens at high density," says Emory disease ecologist Thomas Gillespie. (Getty Images)

By Carol Clark

On July 6 in 1885, Louis Pasteur successfully administered the first vaccine against rabies, one of the most feared diseases of that time. The bite of an infected animal transmits the rabies virus to humans, leading to an agonizing death without the vaccine.

World Zoonoses Day, held July 6 every year, marks this major breakthrough in the fight against zoonoses — diseases caused by germs that spread between animals and people. And yet, 135 years later, despite tremendous advances in science and medicine, the world is struggling to respond to the novel coronavirus — the latest devastating pathogen to spill over from animals.

“We are at a crisis point,” says Thomas Gillespie, associate professor in Emory University’s Department of Environmental Sciences and Rollins School of Public Health. “We have to act now. We cannot forsake this moment. If we don’t radically change our attitudes toward the natural world, things are going to get much, much worse. Pandemics will become increasingly common. What we are experiencing now will seem mild by comparison.”

Gillespie served as an expert reviewer for a report by the United Nations Environmental Program and partners, “Preventing future zoonotic disease outbreaks: Protecting the environment, animals and people in a post-COVID-19 world,” to be released July 6.

“The primary risks for future spillover of zoonotic diseases are deforestation of tropical environments and large-scale industrial farming of animals, specifically pigs and chickens at high density,” Gillespie says.

A disease ecologist, Gillespie studies how germs jump between wildlife, domesticated animals and people. Through this “One Health” approach, he aims to protect humans, ecosystems and biodiversity.

"We're all feeling the impact of the COVID-19 pandemic," Gillespie says. "That's created a sense of urgency that we haven't seen with past discussions of climate change and land-use change."

While vaccine development is important, pathogens can leap from animals to humans much faster than scientists can develop vaccines and treatments. “We also need complementary approaches that focus on the environment,” Gillespie notes. “It’s far cheaper to invest in the prevention of infectious disease outbreaks than to deal with the consequences of a pandemic.”

Gillespie is contributing his “One Health” expertise to an upcoming United Nations forum on the U.N. Sustainable Development Goals.

“The silos have broken down,” Gillespie says. “There is growing awareness that we don’t need a separate forum on climate change and another one for pandemics. Discussions about the environment and health should be integrated and not considered separately so that we can gain momentum. We really need to be sprinting right now. Climate change and the increase in pandemics are both signals that we have reached a tipping point.”

Genetic sequencing links the novel coronavirus that causes COVID-19 to horseshoe bats in China. The first detected outbreak sprang from a live animal market in Wuhan. Gillespie points out, however, that the coronavirus may have been circulating in remote, rural areas before it was detected in Wuhan, a city of 10 million where population density fueled rapid transmission.

He notes that no one has studied the ecological impacts of China’s Three Gorges Dam project. The world’s largest hydroelectric power station, it was built on the Yangtze River on what was previously a mix of secondary forest and agricultural land.

“Live animal markets are definitely dangerous places when it comes to spillover events,” Gillespie says, “but shutting all of them down won’t solve the bigger issue. The markets are just a small piece of a much bigger problem.”

Deforestation to make way for palm oil plantations, which changed the roosting habits of bats, was linked to a major Nipah virus outbreak in Malaysia. Evidence suggests that similar deforestation in West Africa for palm oil production may have played a role in outbreaks of Lassa fever and Ebola.

A meta-analysis by Gillespie and colleagues quantified how fragmentation of forests by agriculture facilitates the spread of pathogens from wildlife. Optimal rates of spillover occur once 40 percent of the forest cover disappears. “That opens a window where you’re going to see more germs jumping species,” Gillespie says. “And tropical environments are at primary risk for pathogen spillover due to simple mathematics — there is a much richer diversity of species living in the tropics than in other environments.”

In the developed world, and rapidly developing parts of the world, people are eating more animal protein and fried food than is recommended for human health. To meet the demand, corporations are clearing natural habitats for cattle ranches, for soybean fields to feed the cattle, and oil palm plantations for cooking oil.

Many species are endangered by these actions. Habitat loss, poaching and disease are the primary threats to the remaining great apes, Gillespie says. COVOID-19 poses a particularly dire situation for apes in danger of extinction, he adds, including bonobos, chimpanzees, gorillas and orangutans. Due to genetic similarities, they are highly susceptible to human respiratory diseases. Gillespie serves as an adviser on great apes to the International Union for Conservation of Nature (IUCN), and has worked to develop IUCN guidelines during the pandemic to limit human contact with the animals while also protecting them from poachers. Gillespie and colleagues created the “Non-human Primate COVID-19 Information Hub” to serve as a real-time resource on the issue.

Current policies fail to factor in the costs of wholesale extraction of resources and the destruction of natural habitats, Gillespie warns. Nature will persist, he adds, even as biodiversity diminishes.

“Nature will push forward, evolution will happen, without regard to human suffering,” Gillespie says. “Meanwhile, we’re ignoring how dependent we are on nature and how fragile we are in the grand scheme of things.”

Gillespie starts off his undergraduate Conservation Biology class with a quiz. Among the questions: How many people are there on the planet? Has the world reached its human carrying capacity?

The last item on the quiz asks students to list 10 species that occur in Atlanta. “None of the students ever writes Homo Sapiens,” Gillespie says. “Many people don’t think of themselves as part of nature anymore. They have this artificial sense that we’re apart from it.”

The pandemic is shifting perspectives. “We’re all feeling the impact of the COVID-19 pandemic,” Gillespie says. “That’s created a sense of urgency that we haven’t seen with past discussions on climate change and land-use change. People are recognizing the linkages between our financial and agricultural systems, the environment and our health. It’s critical right now to make the message as understandable as possible to as many people as possible.”

Follow Thomas Gillespie on Twitter: @BiodiversHealth.

Related:
Great apes and COVID-19: Experts raise the alarm for endangered species
Spillover: Why germs jump species from animals to people
Bat ecology in the era of pandemics

from eScienceCommons https://ift.tt/3eQFQUh

"The primary risks for future spillover of zoonotic diseases are deforestation of tropical environments and large-scale industrial farming of animals, specifically pigs and chickens at high density," says Emory disease ecologist Thomas Gillespie. (Getty Images)

By Carol Clark

On July 6 in 1885, Louis Pasteur successfully administered the first vaccine against rabies, one of the most feared diseases of that time. The bite of an infected animal transmits the rabies virus to humans, leading to an agonizing death without the vaccine.

World Zoonoses Day, held July 6 every year, marks this major breakthrough in the fight against zoonoses — diseases caused by germs that spread between animals and people. And yet, 135 years later, despite tremendous advances in science and medicine, the world is struggling to respond to the novel coronavirus — the latest devastating pathogen to spill over from animals.

“We are at a crisis point,” says Thomas Gillespie, associate professor in Emory University’s Department of Environmental Sciences and Rollins School of Public Health. “We have to act now. We cannot forsake this moment. If we don’t radically change our attitudes toward the natural world, things are going to get much, much worse. Pandemics will become increasingly common. What we are experiencing now will seem mild by comparison.”

Gillespie served as an expert reviewer for a report by the United Nations Environmental Program and partners, “Preventing future zoonotic disease outbreaks: Protecting the environment, animals and people in a post-COVID-19 world,” to be released July 6.

“The primary risks for future spillover of zoonotic diseases are deforestation of tropical environments and large-scale industrial farming of animals, specifically pigs and chickens at high density,” Gillespie says.

A disease ecologist, Gillespie studies how germs jump between wildlife, domesticated animals and people. Through this “One Health” approach, he aims to protect humans, ecosystems and biodiversity.

"We're all feeling the impact of the COVID-19 pandemic," Gillespie says. "That's created a sense of urgency that we haven't seen with past discussions of climate change and land-use change."

While vaccine development is important, pathogens can leap from animals to humans much faster than scientists can develop vaccines and treatments. “We also need complementary approaches that focus on the environment,” Gillespie notes. “It’s far cheaper to invest in the prevention of infectious disease outbreaks than to deal with the consequences of a pandemic.”

Gillespie is contributing his “One Health” expertise to an upcoming United Nations forum on the U.N. Sustainable Development Goals.

“The silos have broken down,” Gillespie says. “There is growing awareness that we don’t need a separate forum on climate change and another one for pandemics. Discussions about the environment and health should be integrated and not considered separately so that we can gain momentum. We really need to be sprinting right now. Climate change and the increase in pandemics are both signals that we have reached a tipping point.”

Genetic sequencing links the novel coronavirus that causes COVID-19 to horseshoe bats in China. The first detected outbreak sprang from a live animal market in Wuhan. Gillespie points out, however, that the coronavirus may have been circulating in remote, rural areas before it was detected in Wuhan, a city of 10 million where population density fueled rapid transmission.

He notes that no one has studied the ecological impacts of China’s Three Gorges Dam project. The world’s largest hydroelectric power station, it was built on the Yangtze River on what was previously a mix of secondary forest and agricultural land.

“Live animal markets are definitely dangerous places when it comes to spillover events,” Gillespie says, “but shutting all of them down won’t solve the bigger issue. The markets are just a small piece of a much bigger problem.”

Deforestation to make way for palm oil plantations, which changed the roosting habits of bats, was linked to a major Nipah virus outbreak in Malaysia. Evidence suggests that similar deforestation in West Africa for palm oil production may have played a role in outbreaks of Lassa fever and Ebola.

A meta-analysis by Gillespie and colleagues quantified how fragmentation of forests by agriculture facilitates the spread of pathogens from wildlife. Optimal rates of spillover occur once 40 percent of the forest cover disappears. “That opens a window where you’re going to see more germs jumping species,” Gillespie says. “And tropical environments are at primary risk for pathogen spillover due to simple mathematics — there is a much richer diversity of species living in the tropics than in other environments.”

In the developed world, and rapidly developing parts of the world, people are eating more animal protein and fried food than is recommended for human health. To meet the demand, corporations are clearing natural habitats for cattle ranches, for soybean fields to feed the cattle, and oil palm plantations for cooking oil.

Many species are endangered by these actions. Habitat loss, poaching and disease are the primary threats to the remaining great apes, Gillespie says. COVOID-19 poses a particularly dire situation for apes in danger of extinction, he adds, including bonobos, chimpanzees, gorillas and orangutans. Due to genetic similarities, they are highly susceptible to human respiratory diseases. Gillespie serves as an adviser on great apes to the International Union for Conservation of Nature (IUCN), and has worked to develop IUCN guidelines during the pandemic to limit human contact with the animals while also protecting them from poachers. Gillespie and colleagues created the “Non-human Primate COVID-19 Information Hub” to serve as a real-time resource on the issue.

Current policies fail to factor in the costs of wholesale extraction of resources and the destruction of natural habitats, Gillespie warns. Nature will persist, he adds, even as biodiversity diminishes.

“Nature will push forward, evolution will happen, without regard to human suffering,” Gillespie says. “Meanwhile, we’re ignoring how dependent we are on nature and how fragile we are in the grand scheme of things.”

Gillespie starts off his undergraduate Conservation Biology class with a quiz. Among the questions: How many people are there on the planet? Has the world reached its human carrying capacity?

The last item on the quiz asks students to list 10 species that occur in Atlanta. “None of the students ever writes Homo Sapiens,” Gillespie says. “Many people don’t think of themselves as part of nature anymore. They have this artificial sense that we’re apart from it.”

The pandemic is shifting perspectives. “We’re all feeling the impact of the COVID-19 pandemic,” Gillespie says. “That’s created a sense of urgency that we haven’t seen with past discussions on climate change and land-use change. People are recognizing the linkages between our financial and agricultural systems, the environment and our health. It’s critical right now to make the message as understandable as possible to as many people as possible.”

Follow Thomas Gillespie on Twitter: @BiodiversHealth.

Related:
Great apes and COVID-19: Experts raise the alarm for endangered species
Spillover: Why germs jump species from animals to people
Bat ecology in the era of pandemics

from eScienceCommons https://ift.tt/3eQFQUh

Moon and Antares in early July

These next few evenings – July 1 and 2, 2020 – let the moon introduce you to Antares. It’s a red star and the brightest star in the constellation Scorpius the Scorpion. Look first for the moon, and the nearby bright star will be Antares.

Any red-looking star that you can see with the unaided eye is either a red giant or red supergiant star. Antares is a red supergiant. This star, which is in the autumn of its years, is expected to explode as a supernova one of these days. No telling when that will be, however. It could happen tomorrow or a million years from now.

Although Antares lies way out there, at some 600 light-years distant, this star easily shines at 1st-magnitude brightness. In order to beam so brightly in our sky, this star must be extremely luminous, that is, intrinsically very brilliant as opposed to merely appearing bright because of a nearer distance.

Antares’ red color indicates a relatively cool surface temperature, and cool stars shine less brilliantly than hot stars of the same size. But Antares is just so big! Its sheer size makes this star more luminous than many stars with higher surface temperatures.

If Antares replaced the sun in our solar system, its circumference would extend beyond the orbit of the fourth planet, Mars. In this illustration, Antares is shown in contrast to another star, Arcturus, and our sun. Image via Wikimedia Commons.

Just how large is this incredible star? It’s not known with absolute certainty, but its radius is thought to be about three times the Earth’s distance from the sun (3 astronomical units). That’s about 3/5 the way from the sun to the orbit of Jupiter, the fifth planet outward from the sun. The radius of Antares is the equivalent of approximately 650 solar radii.

Presuming a radius of 650 solar radii and therefore a diameter of 650 solar diameters, that means the surface area of Antares exceeds that of our sun by some 122,500 times (Antares’ surface area = 650 x 650 = 122,500 solar). But Antares’ volume is actually a few hundred million times greater than the sun’s (Antares’ volume = 650 x 650 x 650 = 271,630,000 solar). And just to think that the sun has the volume of 1,300,000 Earths!

This artist’s concept shows the red supergiant star Antares in the constellation Scorpius. Image via ESO/ M. Kornmesser.

Bottom line: These next two evenings – July 1 and 2, 2020 – let the moon be your guide to Antares, a red supergiant star whose humongous size is truly difficult to fathom!

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

These next few evenings – July 1 and 2, 2020 – let the moon introduce you to Antares. It’s a red star and the brightest star in the constellation Scorpius the Scorpion. Look first for the moon, and the nearby bright star will be Antares.

Any red-looking star that you can see with the unaided eye is either a red giant or red supergiant star. Antares is a red supergiant. This star, which is in the autumn of its years, is expected to explode as a supernova one of these days. No telling when that will be, however. It could happen tomorrow or a million years from now.

Although Antares lies way out there, at some 600 light-years distant, this star easily shines at 1st-magnitude brightness. In order to beam so brightly in our sky, this star must be extremely luminous, that is, intrinsically very brilliant as opposed to merely appearing bright because of a nearer distance.

Antares’ red color indicates a relatively cool surface temperature, and cool stars shine less brilliantly than hot stars of the same size. But Antares is just so big! Its sheer size makes this star more luminous than many stars with higher surface temperatures.

If Antares replaced the sun in our solar system, its circumference would extend beyond the orbit of the fourth planet, Mars. In this illustration, Antares is shown in contrast to another star, Arcturus, and our sun. Image via Wikimedia Commons.

Just how large is this incredible star? It’s not known with absolute certainty, but its radius is thought to be about three times the Earth’s distance from the sun (3 astronomical units). That’s about 3/5 the way from the sun to the orbit of Jupiter, the fifth planet outward from the sun. The radius of Antares is the equivalent of approximately 650 solar radii.

Presuming a radius of 650 solar radii and therefore a diameter of 650 solar diameters, that means the surface area of Antares exceeds that of our sun by some 122,500 times (Antares’ surface area = 650 x 650 = 122,500 solar). But Antares’ volume is actually a few hundred million times greater than the sun’s (Antares’ volume = 650 x 650 x 650 = 271,630,000 solar). And just to think that the sun has the volume of 1,300,000 Earths!

This artist’s concept shows the red supergiant star Antares in the constellation Scorpius. Image via ESO/ M. Kornmesser.

Bottom line: These next two evenings – July 1 and 2, 2020 – let the moon be your guide to Antares, a red supergiant star whose humongous size is truly difficult to fathom!

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

How dust could make some exoplanets more habitable

Three computer simulations depicting how airborne dust can be distributed by winds on rocky exoplanets like Earth. Image via Denis Sergeev/ University of Exeter/ ScienceAlert.

What makes a planet habitable? Various factors can affect a planet’s ability to sustain life, such as temperature, amount of water, composition of both the planet and its atmosphere and the amount of radiation from the host star. Last month, researchers in the U.K. said they’ve found that a common component of atmospheres – dust – could increase the habitability of some exoplanets.

The peer-reviewed results were published in Nature Communications on June 9, 2020.

This is a significant finding, since it suggests that planets with a lot of dust in their atmospheres could have habitable conditions farther from their stars than previously thought. This would, in effect, expand the habitable zone, which is basically the region around a star where temperatures on a rocky could allow liquid water to exist.

Researchers from the University of Exeter, the Met Office and the University of East Anglia (UEA) were involved in the new study.

Effects of dust on the climate of planets. For a tidally locked planet (a) and non-tidally locked planet (b), panels a–d show the base state of the planets, e–h show the short- (stellar) and long-wave (infra-red) forcing (change in surface energy balance) introduced by dust and i–j show the resultant effect of the forcing on the surface temperature. Blue arrows show the motion of the planet around the star, and green arrows show the rotation of the planet relative to the star. Image via Boutle et al./ Nature Communications.

From the paper:

Identification of habitable planets beyond our solar system is a key goal of current and future space missions. Yet habitability depends not only on the stellar irradiance, but equally on constituent parts of the planetary atmosphere. Here we show, for the first time, that radiatively active mineral dust will have a significant impact on the habitability of Earth-like exoplanets.

In our own solar system, Mars typically comes to mind when we think of a dusty world, yet it remains a cold, dry planet on the surface due to its very thin atmosphere. But for some exoplanets, especially those that are tidally locked to their stars, it could be a different situation. Ian Boutle, from both the Met Office and University of Exeter and lead author of the study, said in a statement:

On Earth and Mars, dust storms have both cooling and warming effects on the surface, with the cooling effect typically winning out. But these ‘synchronised orbit’ planets are very different. Here, the dark sides of these planets are in perpetual night, and the warming effect wins out, whereas on the dayside, the cooling effect wins out. The effect is to moderate the temperature extremes, thus making the planet more habitable.

The dust factor is especially significant for planets orbiting red dwarf stars, the most common type of star in our galaxy. Many planets around those stars are likely to be tidally locked, orbiting with one side of the planet always facing the star, just as the moon always keeps one side facing Earth. Those planets would have one side always in daylight, and the other always in darkness. If there is a lot of dust, that could help cool down the hotter day side, and warm the colder night side.

Artist’s concept of a cloudy and rocky exoplanet orbiting a red dwarf star. Dust in the atmospheres of planets like this could moderate the temperature extremes if the planets are tidally locked, helping to make them more habitable. Image via L. Hustak/ J. Olmsted (STScI)/ NASA.

In an interesting scenario, dust could help hot planets retain their surface water, if they have any. A planet that is really hot, like Venus, could be cooled down by enough dust in the atmosphere. The amount of dust would then increase as water starts to be lost on the planet’s surface, which, ironically, in a process called negative climate feedback, would then slow down the loss of water. From the paper:

On tidally-locked planets, dust cools the day-side and warms the night-side, significantly widening the habitable zone. Independent of orbital configuration, we suggest that airborne dust can postpone planetary water loss at the inner edge of the habitable zone, through a feedback involving decreasing ocean coverage and increased dust loading.

The amount of energy a planet receives from its star is an important part of assessing habitability, but as Manoj Joshi from UEA noted, the composition of the atmosphere, including dust, is also very important:

Airborne dust is something that might keep planets habitable, but also obscures our ability to find signs of life on these planets. These effects need to be considered in future research.

The researchers performed a series of simulations of rocky Earth-sized planets and found that naturally occurring mineral dust can have a big impact on the habitability of such planets.

Mars is a very dusty place, and massive dust storms are common, but the dust doesn’t warm the planet much since the atmosphere is so thin. Image via SA/ Roscosmos/ CaSSIS/ CC BY-SA 3.0 IGO/ New Scientist.

Duncan Lyster, who ran an undergraduate experiment as part of the overall study (and now builds his own surfboards), also said:

It’s exciting to see the results of the practical research in my final year of study paying off. I was working on a fascinating exoplanet atmosphere simulation project, and was lucky enough to be part of a group who could take it on to the level of world-class research.

The researchers also point out that dust in a planet’s atmosphere must be taken into account when searching for possible biomarkers in that atmosphere. Those biomarkers could include gases such as oxygen, methane and ozone, and if there also was enough dust, the dust could obscure the detection of them, producing a false negative result. If potential biomarkers were missed in that way, the planet might be erroneously characterized as uninhabitable. Such biomarkers, which will be searched for with upcoming space telescopes like the James Webb Space Telescope (JWST) and others, will be a crucial aspect of the search for evidence of life beyond our solar system. Identifying them is already a challenge due to the extreme distances to these worlds, so knowing the amount of dust in a planetary atmosphere will be important as well. From the paper:

The inclusion of dust significantly obscures key biomarker gases (e.g. ozone, methane) in simulated transmission spectra, implying an important influence on the interpretation of observations. We demonstrate that future observational and theoretical studies of terrestrial exoplanets must consider the effect of dust.

Ian Boutle at the Met Office and University of Exeter, lead author of the new study. Image via Google Scholar.

Nathan Mayne from the University of Exeter, who assisted with the study, also noted how astrophysics in general will play a large role. He said:

Research such as this is only possible by crossing disciplines and combing the excellent understanding and techniques developed to study our own planet’s climate, with cutting edge astrophysics. To be able to involve undergraduate physics students in this, and other projects, also provides an excellent opportunity for those studying with us to directly develop the skills needed in such technical and collaborative projects. With game-changing facilities such as the JWST and E-ELT, becoming available in the near future, and set to provide a huge leap forward in the study of exoplanets, now is a great time to study physics!

The new assessment regarding exoplanetary dust will be very beneficial to scientists who will be looking for biomarkers and other evidence for habitable exoworlds, as well as studying how dust can affect a planet’s climate and environment overall.

Bottom line: Atmospheric dust could increase the habitability of some exoplanets.

Source: Mineral dust increases the habitability of terrestrial planets but confounds biomarker detection

Via University of Exeter

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

Three computer simulations depicting how airborne dust can be distributed by winds on rocky exoplanets like Earth. Image via Denis Sergeev/ University of Exeter/ ScienceAlert.

What makes a planet habitable? Various factors can affect a planet’s ability to sustain life, such as temperature, amount of water, composition of both the planet and its atmosphere and the amount of radiation from the host star. Last month, researchers in the U.K. said they’ve found that a common component of atmospheres – dust – could increase the habitability of some exoplanets.

The peer-reviewed results were published in Nature Communications on June 9, 2020.

This is a significant finding, since it suggests that planets with a lot of dust in their atmospheres could have habitable conditions farther from their stars than previously thought. This would, in effect, expand the habitable zone, which is basically the region around a star where temperatures on a rocky could allow liquid water to exist.

Researchers from the University of Exeter, the Met Office and the University of East Anglia (UEA) were involved in the new study.

Effects of dust on the climate of planets. For a tidally locked planet (a) and non-tidally locked planet (b), panels a–d show the base state of the planets, e–h show the short- (stellar) and long-wave (infra-red) forcing (change in surface energy balance) introduced by dust and i–j show the resultant effect of the forcing on the surface temperature. Blue arrows show the motion of the planet around the star, and green arrows show the rotation of the planet relative to the star. Image via Boutle et al./ Nature Communications.

From the paper:

Identification of habitable planets beyond our solar system is a key goal of current and future space missions. Yet habitability depends not only on the stellar irradiance, but equally on constituent parts of the planetary atmosphere. Here we show, for the first time, that radiatively active mineral dust will have a significant impact on the habitability of Earth-like exoplanets.

In our own solar system, Mars typically comes to mind when we think of a dusty world, yet it remains a cold, dry planet on the surface due to its very thin atmosphere. But for some exoplanets, especially those that are tidally locked to their stars, it could be a different situation. Ian Boutle, from both the Met Office and University of Exeter and lead author of the study, said in a statement:

On Earth and Mars, dust storms have both cooling and warming effects on the surface, with the cooling effect typically winning out. But these ‘synchronised orbit’ planets are very different. Here, the dark sides of these planets are in perpetual night, and the warming effect wins out, whereas on the dayside, the cooling effect wins out. The effect is to moderate the temperature extremes, thus making the planet more habitable.

The dust factor is especially significant for planets orbiting red dwarf stars, the most common type of star in our galaxy. Many planets around those stars are likely to be tidally locked, orbiting with one side of the planet always facing the star, just as the moon always keeps one side facing Earth. Those planets would have one side always in daylight, and the other always in darkness. If there is a lot of dust, that could help cool down the hotter day side, and warm the colder night side.

Artist’s concept of a cloudy and rocky exoplanet orbiting a red dwarf star. Dust in the atmospheres of planets like this could moderate the temperature extremes if the planets are tidally locked, helping to make them more habitable. Image via L. Hustak/ J. Olmsted (STScI)/ NASA.

In an interesting scenario, dust could help hot planets retain their surface water, if they have any. A planet that is really hot, like Venus, could be cooled down by enough dust in the atmosphere. The amount of dust would then increase as water starts to be lost on the planet’s surface, which, ironically, in a process called negative climate feedback, would then slow down the loss of water. From the paper:

On tidally-locked planets, dust cools the day-side and warms the night-side, significantly widening the habitable zone. Independent of orbital configuration, we suggest that airborne dust can postpone planetary water loss at the inner edge of the habitable zone, through a feedback involving decreasing ocean coverage and increased dust loading.

The amount of energy a planet receives from its star is an important part of assessing habitability, but as Manoj Joshi from UEA noted, the composition of the atmosphere, including dust, is also very important:

Airborne dust is something that might keep planets habitable, but also obscures our ability to find signs of life on these planets. These effects need to be considered in future research.

The researchers performed a series of simulations of rocky Earth-sized planets and found that naturally occurring mineral dust can have a big impact on the habitability of such planets.

Mars is a very dusty place, and massive dust storms are common, but the dust doesn’t warm the planet much since the atmosphere is so thin. Image via SA/ Roscosmos/ CaSSIS/ CC BY-SA 3.0 IGO/ New Scientist.

Duncan Lyster, who ran an undergraduate experiment as part of the overall study (and now builds his own surfboards), also said:

It’s exciting to see the results of the practical research in my final year of study paying off. I was working on a fascinating exoplanet atmosphere simulation project, and was lucky enough to be part of a group who could take it on to the level of world-class research.

The researchers also point out that dust in a planet’s atmosphere must be taken into account when searching for possible biomarkers in that atmosphere. Those biomarkers could include gases such as oxygen, methane and ozone, and if there also was enough dust, the dust could obscure the detection of them, producing a false negative result. If potential biomarkers were missed in that way, the planet might be erroneously characterized as uninhabitable. Such biomarkers, which will be searched for with upcoming space telescopes like the James Webb Space Telescope (JWST) and others, will be a crucial aspect of the search for evidence of life beyond our solar system. Identifying them is already a challenge due to the extreme distances to these worlds, so knowing the amount of dust in a planetary atmosphere will be important as well. From the paper:

The inclusion of dust significantly obscures key biomarker gases (e.g. ozone, methane) in simulated transmission spectra, implying an important influence on the interpretation of observations. We demonstrate that future observational and theoretical studies of terrestrial exoplanets must consider the effect of dust.

Ian Boutle at the Met Office and University of Exeter, lead author of the new study. Image via Google Scholar.

Nathan Mayne from the University of Exeter, who assisted with the study, also noted how astrophysics in general will play a large role. He said:

Research such as this is only possible by crossing disciplines and combing the excellent understanding and techniques developed to study our own planet’s climate, with cutting edge astrophysics. To be able to involve undergraduate physics students in this, and other projects, also provides an excellent opportunity for those studying with us to directly develop the skills needed in such technical and collaborative projects. With game-changing facilities such as the JWST and E-ELT, becoming available in the near future, and set to provide a huge leap forward in the study of exoplanets, now is a great time to study physics!

The new assessment regarding exoplanetary dust will be very beneficial to scientists who will be looking for biomarkers and other evidence for habitable exoworlds, as well as studying how dust can affect a planet’s climate and environment overall.

Bottom line: Atmospheric dust could increase the habitability of some exoplanets.

Source: Mineral dust increases the habitability of terrestrial planets but confounds biomarker detection

Via University of Exeter

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

COVID-19: “It could take months to build research up again”

There’s an atmosphere of excitement in Cambridge. After months of not being able to get into labs for anything other than COVID-19 research, universities are beginning to discuss how to reopen facilities.

It’s a conversation that Professor Richard Gilbertson, a children’s cancer researcher and director of the Cancer Research UK Cambridge Centre, is particularly pleased to be having.

Professor Richard Gilbertson.

“Lockdown has meant that lab research is essentially halted.” With universities and other institutions closing their facilities at the beginning of lockdown to all but COVID-19 research, scientists haven’t been able to get in the lab for a few months.

As many researchers in the centre work with cells to study cancer, Gilbertson says their work has quite literally been frozen in time.

“When you shutdown, you have to take the cells and freeze them to minus 80. And then they stay in suspended animation for the period of the lockdown.”

And while a lot of researchers have been able to analyse results and plan future experiments at home during lockdown, they’re itching to get back in the lab. Which is starting to become a reality. Universities are now looking at how to reopen facilities as lockdown rules relax, but it’s going to take scientists a while to get back up and running.

“A lot of experiments can take up to a year to build up again. So the shutdown is pretty devastating.”

Gilbertson says the cells researchers use to study cancer can take weeks or months to grow. “It’s a bit like a garden, you plant seeds and tend the garden and watch things grow in it, and only then are you ready to harvest.”

Scientists have to carefully grow their cellular garden, making sure they’re healthy before they begin their experiments. And while they still have the seeds for their research in the freezer, it will take a while before they’re ready.

“That’s why shutting down and then reopening is not an on off thing, it will take us a while to get back to previous productivity.”

This lag time is particularly problematic for early career researchers, who train in short bursts. “Your average PhD is somewhere between 3 and 4 years, so you can imagine why a year out of that can be absolutely devastating for someone’s training.”

Uncertain times

But it’s not just lab research that’s been affected, it’s everything. “Patients are always first and foremost in our minds,” says Gilbertson, which is why the impact of COVID-19 on clinical trials is particularly worrying.

“Most clinical trials stopped with COVID-19, we stopped enrolling patients onto clinical trials. And that was partly because the ‘machine’ that supports clinical trials was switched to COVID-19, and partly because of the capacity of hospitals. So that’s had a devastating effect for patients who would benefit from those trials.”

And while the immediate impact of COVID-19 on labs, clinical trials and cancer services is clear, it’s likely to be just the beginning.

“Another obvious area of impact is the economy,” says Gilbertson. We announced last week that because of the devasting impact of COVID-19 on our income, we could be forced to cut £150 million per year from our research funding.

“We live in a country that has fabulous cancer research, which is why I moved back here from the US. And yet most of that is funded by the generosity of the public. So periods like this can be devastating, because it can have a long-term knock on effect.”

And this uncertainty could have unseen consequences. “If you’re a new junior investigator, or a post doc, you’re getting to a point in your career where you need to decide if you’re going to stay in science,” says Gilbertson. “In a time of uncertainty, when you don’t know whether there will be grants available, that could sway people’s decisions, and they may go after a different career paths.”

This could mean some of the brightest scientists leave academic research, which would be a huge loss to cancer research.

“If you put all those things together, you can start to see how potentially devastating the pandemic has been for cancer research and cancer patients.”

Together we will still beat cancer

While there’s still a lot of uncertainty, Gilbertson is extremely excited to get the Centre back up and running, even if it’s not at full capacity at first. “With social distancing rules, we’re having to work back from how many people different departments can accommodate at any one time.”

Gilbertson and his colleagues now discussing which work to prioritise when the labs reopen. “We’re starting to think about who should be in the building and why they should be in the building. And that’s not a bad thing – COVID-19 has really made us think hard about prioritising the most important experiments.”

For Gilbertson, he’s particularly excited about two projects. “I’ve been going after a particular type of brain tumour – medulloblastoma – for 30 years, ever since I first saw a child die of it. We’re on the cusp of developing a kinder treatment that we hope would spare children getting radiotherapy, which would be absolutely fantastic. So we’re really chomping at the bit to get that going.”

The other project is a study that aims to understand more about how and why tumours spread to other parts of the body. “We think we’ve uncovered a mechanism that governs metastasis, which would be really exciting.”

But Gilbertson knows that getting these projects back up and running doesn’t just rely on getting scientists back in the lab. It also relies on the generosity of our supporters.

“I don’t think people hear it enough from researchers, but thank you so much for your support. The money you give helps to keep the lights on, keep our machines running, it means we can do those clinical trials, to find new treatments.

“If it wasn’t for that pound you were giving, none of that would happen, it would all go away. And with COVID-19, there’s a possibility that some of it could go away, so we need your support now more than ever.”

Katie 

COVID-19 has slowed us down, but we will never stop. 

> Donate today to help continue life-saving research.

from Cancer Research UK – Science blog https://ift.tt/2Akb9YP

There’s an atmosphere of excitement in Cambridge. After months of not being able to get into labs for anything other than COVID-19 research, universities are beginning to discuss how to reopen facilities.

It’s a conversation that Professor Richard Gilbertson, a children’s cancer researcher and director of the Cancer Research UK Cambridge Centre, is particularly pleased to be having.

Professor Richard Gilbertson.

“Lockdown has meant that lab research is essentially halted.” With universities and other institutions closing their facilities at the beginning of lockdown to all but COVID-19 research, scientists haven’t been able to get in the lab for a few months.

As many researchers in the centre work with cells to study cancer, Gilbertson says their work has quite literally been frozen in time.

“When you shutdown, you have to take the cells and freeze them to minus 80. And then they stay in suspended animation for the period of the lockdown.”

And while a lot of researchers have been able to analyse results and plan future experiments at home during lockdown, they’re itching to get back in the lab. Which is starting to become a reality. Universities are now looking at how to reopen facilities as lockdown rules relax, but it’s going to take scientists a while to get back up and running.

“A lot of experiments can take up to a year to build up again. So the shutdown is pretty devastating.”

Gilbertson says the cells researchers use to study cancer can take weeks or months to grow. “It’s a bit like a garden, you plant seeds and tend the garden and watch things grow in it, and only then are you ready to harvest.”

Scientists have to carefully grow their cellular garden, making sure they’re healthy before they begin their experiments. And while they still have the seeds for their research in the freezer, it will take a while before they’re ready.

“That’s why shutting down and then reopening is not an on off thing, it will take us a while to get back to previous productivity.”

This lag time is particularly problematic for early career researchers, who train in short bursts. “Your average PhD is somewhere between 3 and 4 years, so you can imagine why a year out of that can be absolutely devastating for someone’s training.”

Uncertain times

But it’s not just lab research that’s been affected, it’s everything. “Patients are always first and foremost in our minds,” says Gilbertson, which is why the impact of COVID-19 on clinical trials is particularly worrying.

“Most clinical trials stopped with COVID-19, we stopped enrolling patients onto clinical trials. And that was partly because the ‘machine’ that supports clinical trials was switched to COVID-19, and partly because of the capacity of hospitals. So that’s had a devastating effect for patients who would benefit from those trials.”

And while the immediate impact of COVID-19 on labs, clinical trials and cancer services is clear, it’s likely to be just the beginning.

“Another obvious area of impact is the economy,” says Gilbertson. We announced last week that because of the devasting impact of COVID-19 on our income, we could be forced to cut £150 million per year from our research funding.

“We live in a country that has fabulous cancer research, which is why I moved back here from the US. And yet most of that is funded by the generosity of the public. So periods like this can be devastating, because it can have a long-term knock on effect.”

And this uncertainty could have unseen consequences. “If you’re a new junior investigator, or a post doc, you’re getting to a point in your career where you need to decide if you’re going to stay in science,” says Gilbertson. “In a time of uncertainty, when you don’t know whether there will be grants available, that could sway people’s decisions, and they may go after a different career paths.”

This could mean some of the brightest scientists leave academic research, which would be a huge loss to cancer research.

“If you put all those things together, you can start to see how potentially devastating the pandemic has been for cancer research and cancer patients.”

Together we will still beat cancer

While there’s still a lot of uncertainty, Gilbertson is extremely excited to get the Centre back up and running, even if it’s not at full capacity at first. “With social distancing rules, we’re having to work back from how many people different departments can accommodate at any one time.”

Gilbertson and his colleagues now discussing which work to prioritise when the labs reopen. “We’re starting to think about who should be in the building and why they should be in the building. And that’s not a bad thing – COVID-19 has really made us think hard about prioritising the most important experiments.”

For Gilbertson, he’s particularly excited about two projects. “I’ve been going after a particular type of brain tumour – medulloblastoma – for 30 years, ever since I first saw a child die of it. We’re on the cusp of developing a kinder treatment that we hope would spare children getting radiotherapy, which would be absolutely fantastic. So we’re really chomping at the bit to get that going.”

The other project is a study that aims to understand more about how and why tumours spread to other parts of the body. “We think we’ve uncovered a mechanism that governs metastasis, which would be really exciting.”

But Gilbertson knows that getting these projects back up and running doesn’t just rely on getting scientists back in the lab. It also relies on the generosity of our supporters.

“I don’t think people hear it enough from researchers, but thank you so much for your support. The money you give helps to keep the lights on, keep our machines running, it means we can do those clinical trials, to find new treatments.

“If it wasn’t for that pound you were giving, none of that would happen, it would all go away. And with COVID-19, there’s a possibility that some of it could go away, so we need your support now more than ever.”

Katie 

COVID-19 has slowed us down, but we will never stop. 

> Donate today to help continue life-saving research.

from Cancer Research UK – Science blog https://ift.tt/2Akb9YP