Breakthrough Listen and TESS team up for SETI

Image via Breakthrough Listen / Danielle Futselaar/ SETI Institute.

In recent decades, missions to planets and moons in our solar system have been alert for signs of microbial life. Astronomers have found thousands of exoplanets, or worlds orbiting distance suns. There’ve been the traditional searches for intelligent radio signals (SETI), now including searches for light signals (optical SETI). Scientists now speak of technosignatures – signatures of advanced technologies – as distinct from biosignatures. Late last month, two major programs announced they’re joining forces in the search for intelligent life elsewhere in our galaxy. Breakthrough Listen, part of Breakthrough Initiatives, has announced it will collaborate with NASA’s Transiting Exoplanet Survey Satellite (TESS) mission. Breakthrough Listen has $100 million in funding and is using thousands of hours of dedicated telescope time on state-of-the-art earthly facilities – targeting a million nearby stars and the centers of 100 galaxies – in its search for technosignatures. TESS, meanwhile, uses a novel highly-elliptical orbit around Earth (at its farthest from us, it’s as far as the moon) in its task of seeking – and finding – new exoplanets, including smaller, rocky worlds like Earth.

The new initiative was announced at the International Astronautical Congress (IAC) in Washington, DC on October 23, 2019. It’ll be led by TESS Deputy Science Director Sara Seager, S. Pete Worden, Executive Director of Breakthrough Initiatives and Andrew Siemion, leader of the Breakthrough Listen science team.

The collaboration will allow Breakthrough Listen to focus on more specific targets, rocky planets like Earth that may be habitable. Using data from TESS, it is estimated that over 1,000 new “objects of interest” will be added to Breakthrough Listen’s target list. The project will utilize a wide range of telescopes, including Green Bank, Parkes Telescopes, MeerKAT2, Automated Planet Finder, VERITAS4, NenuFAR, FAST5, Murchison Widefield Array, LOFAR stations in Ireland and Sweden, Jodrell Bank Observatory, e-MERLIN6, Keck Observatory, Sardinia Radio Telescope and Allen Telescope Array7. Worden said:

It’s exciting that the world’s most powerful SETI search, with our partner facilities across the globe, will be collaborating with the TESS team and our most capable planet-hunting machine. We’re looking forward to working together as we try to answer one of the most profound questions about our place in the Universe: Are we alone?

Artist’s concept of a Dyson sphere, a hypothetical construction around a star to harness the star’s energy. This is one type of techno signature that could be detected by the new Breakthrough Listen/TESS project. Image via SentientDevelopments.com.

TESS is the planet-hunting successor to the Kepler Space Telescope. Like Kepler, it finds planets by detecting their transits in front of their stars. While Kepler focused on distant stars in certain patches of the sky, TESS looks at stars much closer to us, over about 85% of the sky – 400 times more than Kepler – with a prime focus on rocky worlds similar to Earth in size and mass. TESS was launched in April 2018, and has four wide-field cameras, each monitoring a region of sky 24 degrees across (about the width of your hand held at arm’s length). Light curves – how the brightness of stars changes over time – for 20,000 stars are measured every 2 minutes, and the brightness of every pixel in the cameras is recorded every 30 minutes.

Over 4,000 exoplanets have been confirmed so far in the past three decades, with many of those coming from Kepler. But TESS is now already quickly adding to that list, and is predicted to find at least 10,000 new exoplanets. Overall, scientists now estimate there are billions of planets in our galaxy alone!

To date, most searches for extraterrestrial intelligence have been limited to using radio telescopes to look for alien radio signals. Breakthrough Listen and the search for technosignatures will greatly expand on that. Image via sdecoret/Shutterstock/Discover.

TESS has a unique advantage in working together with Breakthrough Listen. All the planetary systems it discovers will be edge-on as viewed from Earth. The majority of radio signal leakage on Earth – about 70% – comes from the plane of Earth’s orbit. If an alien civilization had transmitters emitting radio signals in a similar manner, the best chance of detecting them is to view the planetary systems edge-on.

This, of course, has only to do with radio signals. As many scientists now suggest, there are other possibilities for detecting signs of an advanced alien civilization. If such a civilization was much further ahead technologically than us, it might not use radio at all anymore. Both Breakthrough Listen and TESS are capable of finding other kinds of anomalies as well, such as megastructures in orbit around a planet or star, perhaps resembling a Dyson sphere. Boyajian’s Star – aka Tabby’s Star – is a good example of a star exhibiting weird, potentially alien-related behavior, as Siemion noted:

The discovery by the Kepler spacecraft of Boyajian’s Star, an object with wild, and apparently random, variations in its light curve, sparked great excitement and a range of possible explanations, of which megastructures were just one. Follow-up observations have suggested that dust particles in orbit around the star are responsible for the dimming, but studies of anomalies like this are expanding our knowledge of astrophysics, as well as casting a wider net in the search for technosignatures.

Artist’s concept of a super-Earth exoplanet orbiting a nearby star. The TESS mission focuses on searching for rocky planets like this where life might be possible. Image via M. Kornmesser/ESO/MIT News.

For those of us hoping to find evidence of intelligent alien life, this new collaboration is exciting. It will help to better refine search efforts as we learn more about which planetary systems would be the best to focus on instead of the more random kinds of searches done in the past. TESS, and other future planet-hunting telescopes, will be invaluable in determining which exoplanets in our galaxy are the most likely to be habitable, allowing Breakthrough Listen and other SETI-type searches to focus more on such worlds as possible homes for alien intelligence. In Seager’s words:

We are very enthusiastic about joining the Breakthrough Listen SETI search. Out of all the exoplanet endeavors only SETI holds the promise for identifying signs of intelligent life.

Bottom line: Breakthrough Listen and NASA’s exoplanet-hunting mission TESS are teaming up in the search for advanced alien life.

Via Breakthrough Initiatives

from EarthSky https://ift.tt/2C6oEsh

Image via Breakthrough Listen / Danielle Futselaar/ SETI Institute.

In recent decades, missions to planets and moons in our solar system have been alert for signs of microbial life. Astronomers have found thousands of exoplanets, or worlds orbiting distance suns. There’ve been the traditional searches for intelligent radio signals (SETI), now including searches for light signals (optical SETI). Scientists now speak of technosignatures – signatures of advanced technologies – as distinct from biosignatures. Late last month, two major programs announced they’re joining forces in the search for intelligent life elsewhere in our galaxy. Breakthrough Listen, part of Breakthrough Initiatives, has announced it will collaborate with NASA’s Transiting Exoplanet Survey Satellite (TESS) mission. Breakthrough Listen has $100 million in funding and is using thousands of hours of dedicated telescope time on state-of-the-art earthly facilities – targeting a million nearby stars and the centers of 100 galaxies – in its search for technosignatures. TESS, meanwhile, uses a novel highly-elliptical orbit around Earth (at its farthest from us, it’s as far as the moon) in its task of seeking – and finding – new exoplanets, including smaller, rocky worlds like Earth.

The new initiative was announced at the International Astronautical Congress (IAC) in Washington, DC on October 23, 2019. It’ll be led by TESS Deputy Science Director Sara Seager, S. Pete Worden, Executive Director of Breakthrough Initiatives and Andrew Siemion, leader of the Breakthrough Listen science team.

The collaboration will allow Breakthrough Listen to focus on more specific targets, rocky planets like Earth that may be habitable. Using data from TESS, it is estimated that over 1,000 new “objects of interest” will be added to Breakthrough Listen’s target list. The project will utilize a wide range of telescopes, including Green Bank, Parkes Telescopes, MeerKAT2, Automated Planet Finder, VERITAS4, NenuFAR, FAST5, Murchison Widefield Array, LOFAR stations in Ireland and Sweden, Jodrell Bank Observatory, e-MERLIN6, Keck Observatory, Sardinia Radio Telescope and Allen Telescope Array7. Worden said:

It’s exciting that the world’s most powerful SETI search, with our partner facilities across the globe, will be collaborating with the TESS team and our most capable planet-hunting machine. We’re looking forward to working together as we try to answer one of the most profound questions about our place in the Universe: Are we alone?

Artist’s concept of a Dyson sphere, a hypothetical construction around a star to harness the star’s energy. This is one type of techno signature that could be detected by the new Breakthrough Listen/TESS project. Image via SentientDevelopments.com.

TESS is the planet-hunting successor to the Kepler Space Telescope. Like Kepler, it finds planets by detecting their transits in front of their stars. While Kepler focused on distant stars in certain patches of the sky, TESS looks at stars much closer to us, over about 85% of the sky – 400 times more than Kepler – with a prime focus on rocky worlds similar to Earth in size and mass. TESS was launched in April 2018, and has four wide-field cameras, each monitoring a region of sky 24 degrees across (about the width of your hand held at arm’s length). Light curves – how the brightness of stars changes over time – for 20,000 stars are measured every 2 minutes, and the brightness of every pixel in the cameras is recorded every 30 minutes.

Over 4,000 exoplanets have been confirmed so far in the past three decades, with many of those coming from Kepler. But TESS is now already quickly adding to that list, and is predicted to find at least 10,000 new exoplanets. Overall, scientists now estimate there are billions of planets in our galaxy alone!

To date, most searches for extraterrestrial intelligence have been limited to using radio telescopes to look for alien radio signals. Breakthrough Listen and the search for technosignatures will greatly expand on that. Image via sdecoret/Shutterstock/Discover.

TESS has a unique advantage in working together with Breakthrough Listen. All the planetary systems it discovers will be edge-on as viewed from Earth. The majority of radio signal leakage on Earth – about 70% – comes from the plane of Earth’s orbit. If an alien civilization had transmitters emitting radio signals in a similar manner, the best chance of detecting them is to view the planetary systems edge-on.

This, of course, has only to do with radio signals. As many scientists now suggest, there are other possibilities for detecting signs of an advanced alien civilization. If such a civilization was much further ahead technologically than us, it might not use radio at all anymore. Both Breakthrough Listen and TESS are capable of finding other kinds of anomalies as well, such as megastructures in orbit around a planet or star, perhaps resembling a Dyson sphere. Boyajian’s Star – aka Tabby’s Star – is a good example of a star exhibiting weird, potentially alien-related behavior, as Siemion noted:

The discovery by the Kepler spacecraft of Boyajian’s Star, an object with wild, and apparently random, variations in its light curve, sparked great excitement and a range of possible explanations, of which megastructures were just one. Follow-up observations have suggested that dust particles in orbit around the star are responsible for the dimming, but studies of anomalies like this are expanding our knowledge of astrophysics, as well as casting a wider net in the search for technosignatures.

Artist’s concept of a super-Earth exoplanet orbiting a nearby star. The TESS mission focuses on searching for rocky planets like this where life might be possible. Image via M. Kornmesser/ESO/MIT News.

For those of us hoping to find evidence of intelligent alien life, this new collaboration is exciting. It will help to better refine search efforts as we learn more about which planetary systems would be the best to focus on instead of the more random kinds of searches done in the past. TESS, and other future planet-hunting telescopes, will be invaluable in determining which exoplanets in our galaxy are the most likely to be habitable, allowing Breakthrough Listen and other SETI-type searches to focus more on such worlds as possible homes for alien intelligence. In Seager’s words:

We are very enthusiastic about joining the Breakthrough Listen SETI search. Out of all the exoplanet endeavors only SETI holds the promise for identifying signs of intelligent life.

Bottom line: Breakthrough Listen and NASA’s exoplanet-hunting mission TESS are teaming up in the search for advanced alien life.

Via Breakthrough Initiatives

from EarthSky https://ift.tt/2C6oEsh

Video: Watch scientists excavate a giant anthill

We noticed this video clip – originally published at our site in 2013 – was getting a lot of notice today. It deserves it! It’s amazing.

This video clip, from a 2006 documentary (Ants! Natures Secret Power), shows the excavation of a giant colony of grass-cutter ants. Over the course of 3 days, scientists pumped 10 tons of cement into an abandoned ant hill. After weeks of digging, the colony’s intricate and impressive structure is revealed.

If this clip piques your interest, know that you can also view the full-length documentary here. The documentary introduces us to the world of ants through the eyes of Bert Hölldobler, entomologist and friend of world-renowned scientist E.O. Wilson. Award-winning cinematographer Wolfgang Thaler captured the scene.

The more I learn about ants, the more my mind is blown.

Video still from Ants! Nature’s Secret Power

Bottom line: Video clip from Ants! Nature’s Secret Power by cameraman Wolfgang Thaler and entomologist Bert Hölldobler.

from EarthSky https://ift.tt/34nKTpJ

We noticed this video clip – originally published at our site in 2013 – was getting a lot of notice today. It deserves it! It’s amazing.

This video clip, from a 2006 documentary (Ants! Natures Secret Power), shows the excavation of a giant colony of grass-cutter ants. Over the course of 3 days, scientists pumped 10 tons of cement into an abandoned ant hill. After weeks of digging, the colony’s intricate and impressive structure is revealed.

If this clip piques your interest, know that you can also view the full-length documentary here. The documentary introduces us to the world of ants through the eyes of Bert Hölldobler, entomologist and friend of world-renowned scientist E.O. Wilson. Award-winning cinematographer Wolfgang Thaler captured the scene.

The more I learn about ants, the more my mind is blown.

Video still from Ants! Nature’s Secret Power

Bottom line: Video clip from Ants! Nature’s Secret Power by cameraman Wolfgang Thaler and entomologist Bert Hölldobler.

from EarthSky https://ift.tt/34nKTpJ

Year’s earliest solar noon on November 3

Solar noon isn’t necessarily a clock event, although clock noon and your solar noon do sometimes coincide. Solar noon is when the sun reaches its highest point for the day in your sky. Image via SolarZentochi.

November 3, 2019, ushers in the earliest solar noon – for the whole year and for the entire globe – by the clock. Solar noon is a natural rather than artificial construct, although our clocks and calendars measure its continual shift throughout the year. Solar noon – aka midday – refers to that passing instant when the sun reaches its highest point for the day, midway between sunrise and sunset. If you reside along the centerline of your time zone, then solar noon – or midday – comes at 11:44 a.m. by your clock every year in early November. If you’re not on your time zone’s centerline – and most of us aren’t – solar noon happens a bit earlier or later by your clock, depending on your offset from your time zone’s centerline.

Obscure? Possibly. But the shift in solar noon is tied to a phenomenon that many people around the world will notice in the coming weeks. That is, the earliest solar noon of the year is a prelude to the year’s earliest sunset in the Northern Hemisphere – and the year’s earliest sunrise in the Southern Hemisphere.

You thought the earliest sunset for the Northern Hemisphere came at the December solstice? It doesn’t. It happens well before that solstice, for a reason that’s related to the earliest solar noon on November 3.

EarthSky 2020 lunar calendars are available! They make great gifts. Order now. Going fast!

This is what’s called an analemma. It shows you the sun’s declination – angular distance north or south of the celestial equator – and the difference (in minutes) between the sun time and clock time for every day of the year. Visit Stanford Solar Center for more information on the analemma.

The meridian is the imaginary semicircle that arcs across the sky from due north to due south. The sun climbs to its highest point for the day when it crosses your meridian at solar noon.

Earliest and latest solar noons, and the length of the day. Starting on November 3, 2019, from everywhere worldwide, the days (as measured from one solar noon to the next) somewhat exceed 24 hours in duration. Day by day, solar noon comes later and later by the clock, lessening the discrepancy between sun time and clock time. At long last – on December 25, 2019 – the sun and the clock agree with one another, with solar noon coming at 12 noon by the clock (for those at the centerline of a given time zone).

Although the sun and clock will agree on December 25, 2019, the duration of the solar day – as measured from one solar noon to the next – will continue to exceed 24 hours each day for another six weeks.

Finally, the latest solar noon of the year will arrive on February 11, 2020, at 12:14 p.m. by the clock (at the time zone centerline).

And, for everyone, everywhere worldwide, solar noon comes some 30 minutes earlier by the clock on November 3, 2019, than it will on February 11, 2020.

Want to know the clock time for solar noon (midday) at your location? Visit Sunrise Sunset Calendars, remembering to check the solar noon box.

Want to know the time difference between sun and clock for any date? Go to AstroPixels.com and look under the equation of time column.

The equation of time graph shows the difference between sun and clock time. In early November, the clock is a maximum 16 minutes behind the sun (solar noon = 11:44 a.m. clock time). In February, the clock is a maximum of 14 minutes ahead of the sun (solar noon = 12:14 p.m. clock time). On or near April 15, June 15, September 1 and December 25, the sun and clock agree.

Solar noon and earliest sunset (and/or sunrise). So … November 3, 2019 marks the earliest solar noon of the year for the whole globe. What’s more, residents at the Earth’s equator have their earliest sunrise and sunset on November 3. That’s because, at the equator, the daylight hours remain virtually the same throughout the year – so the earliest sunrise, earliest solar noon and earliest sunset all fall on the same day.

Elsewhere – within the tropical and temperate regions of the world – the shortest period of daylight happens on the day of the winter solstice, and the longest period of daylight on the summer solstice. So if you live near the Arctic Circle, your earliest sunset doesn’t happen until around the December (winter) solstice; or if you live near the Antarctic Circle, your earliest sunrise doesn’t take place until around the December (summer) solstice.

That’s in spite of the earliest solar noon coming in early November all over the world.

Read more: December solstice starts shortest season

Stephen Aman shares his map of the United States that lists the dates of the year’s earliest sunset for various latitudes. Thank you, Stephen!

If you live north of the equator but south of the Arctic Circle, your earliest sunset occurs somewhere between November 3, 2019, and December 22, 2019. In the Northern Hemisphere, those living closer to the equator have an earlier date for their earliest sunset; and those lodging closer to the Arctic Circle have a later date for their earliest sunset.

We give the approximate dates for the earliest sunset in the Northern Hemisphere:

15 degrees north latitude
Earliest sunset on or near November 23

30 degrees north latitude
Earliest sunset on or near December 1

45 degrees north latitude
Earliest sunset on or near December 10

60 degrees north latitude
Earliest sunset on or near December 17

In the Southern Hemisphere, it’s your earliest sunrise that takes place between November 3, 2019, and December 22, 2019. The closer you live to the equator, the earlier the date for the earliest sunrise; and the closer you live to the Antarctic Circle, the later the date for the earliest sunrise. Because comparable latitudes north/south of the equator have the same approximate dates for earliest sunset/earliest sunrise, the dates for the Southern Hemisphere’s earliest sunrises can be gleaned from the listing above.

In the Northern Hemisphere, the latest sunrise must wait till after the Northern Hemisphere’s December winter solstice; and in the Southern Hemisphere, it’s the latest sunset that must wait till after the Southern Hemisphere’s December summer solstice. Those living closer to the Arctic or Antarctic Circles have an earlier date for their latest sunrise/latest sunset; and those lodging closer to the Earth’s equator have a later date for their latest sunrise/latest sunset. Here are the approximate dates for the Northern Hemisphere’s latest sunrise/Southern Hemisphere’s latest sunset at various latitudes:

60 degrees latitude: December 27
45 degrees latitude: January 2
30 degrees latitude: January 11
15 degrees latitude: January 23

Two reasons account for the unequal length of the solar day over the year. First and foremost, the tilt of the Earth’s axis causes the solar day to be more than 24 hours long around the solstices yet less than 24 hours long around the equinoxes. However, Earth’s eccentric orbit plays a secondary role, either accentuating or lessening the effect. At the December solstice, the Earth is some 3 million miles (5 million km) closer to the sun, and moving more swiftly in its orbit, than on the June solstice. Therefore, the longer-than-average solar day at the December solstice (24 hours + 30 seconds) outlasts the longer-than-average solar day at the June solstice (24 hours + 13 seconds).

The solar day is longer than 24 hours at and around the solstices yet less than 24 hours at and around the equinoxes. Roughly midway between a solstice and an equinox, the solar day lasts for 24 hours. Table via Mathematical Astronomy Morsels by Jean Meeus (page 346).

Bottom line: November 3 brings the earliest noon of the year, by nature’s clock. Earliest solar noon is a harbinger of 2019’s earliest Northern Hemisphere sunset – and earliest Southern Hemisphere sunrise – both due between now and the December solstice.

Need a good sky almanac? Try these recommended almanacs

from EarthSky https://ift.tt/2C3W6Qh

Solar noon isn’t necessarily a clock event, although clock noon and your solar noon do sometimes coincide. Solar noon is when the sun reaches its highest point for the day in your sky. Image via SolarZentochi.

November 3, 2019, ushers in the earliest solar noon – for the whole year and for the entire globe – by the clock. Solar noon is a natural rather than artificial construct, although our clocks and calendars measure its continual shift throughout the year. Solar noon – aka midday – refers to that passing instant when the sun reaches its highest point for the day, midway between sunrise and sunset. If you reside along the centerline of your time zone, then solar noon – or midday – comes at 11:44 a.m. by your clock every year in early November. If you’re not on your time zone’s centerline – and most of us aren’t – solar noon happens a bit earlier or later by your clock, depending on your offset from your time zone’s centerline.

Obscure? Possibly. But the shift in solar noon is tied to a phenomenon that many people around the world will notice in the coming weeks. That is, the earliest solar noon of the year is a prelude to the year’s earliest sunset in the Northern Hemisphere – and the year’s earliest sunrise in the Southern Hemisphere.

You thought the earliest sunset for the Northern Hemisphere came at the December solstice? It doesn’t. It happens well before that solstice, for a reason that’s related to the earliest solar noon on November 3.

EarthSky 2020 lunar calendars are available! They make great gifts. Order now. Going fast!

This is what’s called an analemma. It shows you the sun’s declination – angular distance north or south of the celestial equator – and the difference (in minutes) between the sun time and clock time for every day of the year. Visit Stanford Solar Center for more information on the analemma.

The meridian is the imaginary semicircle that arcs across the sky from due north to due south. The sun climbs to its highest point for the day when it crosses your meridian at solar noon.

Earliest and latest solar noons, and the length of the day. Starting on November 3, 2019, from everywhere worldwide, the days (as measured from one solar noon to the next) somewhat exceed 24 hours in duration. Day by day, solar noon comes later and later by the clock, lessening the discrepancy between sun time and clock time. At long last – on December 25, 2019 – the sun and the clock agree with one another, with solar noon coming at 12 noon by the clock (for those at the centerline of a given time zone).

Although the sun and clock will agree on December 25, 2019, the duration of the solar day – as measured from one solar noon to the next – will continue to exceed 24 hours each day for another six weeks.

Finally, the latest solar noon of the year will arrive on February 11, 2020, at 12:14 p.m. by the clock (at the time zone centerline).

And, for everyone, everywhere worldwide, solar noon comes some 30 minutes earlier by the clock on November 3, 2019, than it will on February 11, 2020.

Want to know the clock time for solar noon (midday) at your location? Visit Sunrise Sunset Calendars, remembering to check the solar noon box.

Want to know the time difference between sun and clock for any date? Go to AstroPixels.com and look under the equation of time column.

The equation of time graph shows the difference between sun and clock time. In early November, the clock is a maximum 16 minutes behind the sun (solar noon = 11:44 a.m. clock time). In February, the clock is a maximum of 14 minutes ahead of the sun (solar noon = 12:14 p.m. clock time). On or near April 15, June 15, September 1 and December 25, the sun and clock agree.

Solar noon and earliest sunset (and/or sunrise). So … November 3, 2019 marks the earliest solar noon of the year for the whole globe. What’s more, residents at the Earth’s equator have their earliest sunrise and sunset on November 3. That’s because, at the equator, the daylight hours remain virtually the same throughout the year – so the earliest sunrise, earliest solar noon and earliest sunset all fall on the same day.

Elsewhere – within the tropical and temperate regions of the world – the shortest period of daylight happens on the day of the winter solstice, and the longest period of daylight on the summer solstice. So if you live near the Arctic Circle, your earliest sunset doesn’t happen until around the December (winter) solstice; or if you live near the Antarctic Circle, your earliest sunrise doesn’t take place until around the December (summer) solstice.

That’s in spite of the earliest solar noon coming in early November all over the world.

Read more: December solstice starts shortest season

Stephen Aman shares his map of the United States that lists the dates of the year’s earliest sunset for various latitudes. Thank you, Stephen!

If you live north of the equator but south of the Arctic Circle, your earliest sunset occurs somewhere between November 3, 2019, and December 22, 2019. In the Northern Hemisphere, those living closer to the equator have an earlier date for their earliest sunset; and those lodging closer to the Arctic Circle have a later date for their earliest sunset.

We give the approximate dates for the earliest sunset in the Northern Hemisphere:

15 degrees north latitude
Earliest sunset on or near November 23

30 degrees north latitude
Earliest sunset on or near December 1

45 degrees north latitude
Earliest sunset on or near December 10

60 degrees north latitude
Earliest sunset on or near December 17

In the Southern Hemisphere, it’s your earliest sunrise that takes place between November 3, 2019, and December 22, 2019. The closer you live to the equator, the earlier the date for the earliest sunrise; and the closer you live to the Antarctic Circle, the later the date for the earliest sunrise. Because comparable latitudes north/south of the equator have the same approximate dates for earliest sunset/earliest sunrise, the dates for the Southern Hemisphere’s earliest sunrises can be gleaned from the listing above.

In the Northern Hemisphere, the latest sunrise must wait till after the Northern Hemisphere’s December winter solstice; and in the Southern Hemisphere, it’s the latest sunset that must wait till after the Southern Hemisphere’s December summer solstice. Those living closer to the Arctic or Antarctic Circles have an earlier date for their latest sunrise/latest sunset; and those lodging closer to the Earth’s equator have a later date for their latest sunrise/latest sunset. Here are the approximate dates for the Northern Hemisphere’s latest sunrise/Southern Hemisphere’s latest sunset at various latitudes:

60 degrees latitude: December 27
45 degrees latitude: January 2
30 degrees latitude: January 11
15 degrees latitude: January 23

Two reasons account for the unequal length of the solar day over the year. First and foremost, the tilt of the Earth’s axis causes the solar day to be more than 24 hours long around the solstices yet less than 24 hours long around the equinoxes. However, Earth’s eccentric orbit plays a secondary role, either accentuating or lessening the effect. At the December solstice, the Earth is some 3 million miles (5 million km) closer to the sun, and moving more swiftly in its orbit, than on the June solstice. Therefore, the longer-than-average solar day at the December solstice (24 hours + 30 seconds) outlasts the longer-than-average solar day at the June solstice (24 hours + 13 seconds).

The solar day is longer than 24 hours at and around the solstices yet less than 24 hours at and around the equinoxes. Roughly midway between a solstice and an equinox, the solar day lasts for 24 hours. Table via Mathematical Astronomy Morsels by Jean Meeus (page 346).

Bottom line: November 3 brings the earliest noon of the year, by nature’s clock. Earliest solar noon is a harbinger of 2019’s earliest Northern Hemisphere sunset – and earliest Southern Hemisphere sunrise – both due between now and the December solstice.

Need a good sky almanac? Try these recommended almanacs

from EarthSky https://ift.tt/2C3W6Qh

Around now, watch for Taurid fireballs

We haven’t heard from many people who’ve seen fireballs in either of the long-lasting South or North Taurid meteor showers this year. Still, it’s always worth keeping an eye out. Various sources give wildly different dates for the peak date of South Taurids (active from late September to late November). November 6, 2019, is one of those predicted dates. November 4 and 5, 2019, might be good nights to watch for meteors, too, possibly featuring a higher-than-average rate of South Taurid meteors. There is less moonlight tonight and tomorrow night – November 2 and 3, 2019 – so don’t discount these nights, either.

Click here for the moonset times in your sky, remembering to check the moonrise and moonset box.

Skywatchers are still remembering the Taurid fireballs they saw in 2015. The Taurids appear to have a 7-year cycle of bright fireballs, and 2015 was apparently a peak year! Read more about that, and see more fireball photos, here.

2019? Not so much. But you never know.

The moon sets at early evening on November 2, 2019, leaving dark skies for meteor watching. Will you see any? We can’t know. But we do know you won’t, if you don’t watch.

Both the South and North Taurids (which is active from late October to early December, and peaks somewhere around November 12) are long, spread-out showers with no well-defined peak. During the peak nights for the South Taurid meteor shower, you might see as many as five meteors per hour. But The American Meteor Society explains what – in some years – can be awesome about the Taurid meteor showers:

The Taurids (both branches) are rich in fireballs and are often responsible for increased number of fireball reports from September through November.

Fireballs are the name of the game for the Taurids.

Seeing a Taurid fireball – even if it’s just one – counts as a big thrill. And, by the way, a fireball is just another word for a particularly bright meteor.

Eliot Herman in Tuscon, Arizona, caught this bright Taurid on October 28, 2016. Go to his Flickr page if you want to see it larger. Nice colors!

On any given night, these rather slow-moving meteors produce the greatest numbers in the few hours after midnight. At that time, the moon will have set or will be close to setting. Because the waxing (increasing) moon will set an hour later with each passing night, you’ll have more moon-free viewing on November 2 and 3 than the two following nights (November 4 and 5).

So we’re guaranteed to have deliciously dark skies for the South Taurids in the wee hours after midnight tonight, to highlight any Taurid fireball that might come whizzing by.

Click here to find out when the moon sets in your sky, remembering to check the moonrise and moonset box.

You can see this meteor is radiating from the constellation Taurus the Bull. See that V-shaped pattern to the right of Orion? The three Belt stars of Orion point to it. That’s the Bull’s Face. Eliot Herman in Tucson caught this Taurid meteor, too, in 2015. The bright object was the moon! Thanks, Eliot.

The other Taurid shower – the North Taurids – should add a few more meteors to the mix from late night until dawn.

And again … the Taurid showers do not exhibit strong peaks. So if you’re clouded out tonight and tomorrow, no problem. Just keep watching. The two Taurid showers tend to overlap and to plateau in activity during the first few weeks in November.

If you trace the South Taurid meteors backwards, they all appear to radiate from the constellation Taurus the Bull. As always, you don’t have to identify a meteor shower’s radiant point to watch the meteor shower. Just lie back comfortably and look up, in the hours between midnight and dawn.

By the way, the constellation Taurus itself is full of interesting things to see such as the Pleiades star cluster, the V-shaped Hyades cluster with bright Aldebaran in its midst.

Just be aware … you don’t need to find Taurus to watch the Taurid shower, for these meteors streak all over the sky.

Bottom line: The annual South Taurid meteor shower has been going on throughout October, and now the North Taurids have started as well. The peaks of these showers aren’t well defined, but the South Taurids might be peaking in the first week of November, 2019. Watch for them.

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

EarthSky’s meteor shower guide for 2019

See it! Best photos of 2015 Taurid fireballs

from EarthSky https://ift.tt/2OmUq7U

We haven’t heard from many people who’ve seen fireballs in either of the long-lasting South or North Taurid meteor showers this year. Still, it’s always worth keeping an eye out. Various sources give wildly different dates for the peak date of South Taurids (active from late September to late November). November 6, 2019, is one of those predicted dates. November 4 and 5, 2019, might be good nights to watch for meteors, too, possibly featuring a higher-than-average rate of South Taurid meteors. There is less moonlight tonight and tomorrow night – November 2 and 3, 2019 – so don’t discount these nights, either.

Click here for the moonset times in your sky, remembering to check the moonrise and moonset box.

Skywatchers are still remembering the Taurid fireballs they saw in 2015. The Taurids appear to have a 7-year cycle of bright fireballs, and 2015 was apparently a peak year! Read more about that, and see more fireball photos, here.

2019? Not so much. But you never know.

The moon sets at early evening on November 2, 2019, leaving dark skies for meteor watching. Will you see any? We can’t know. But we do know you won’t, if you don’t watch.

Both the South and North Taurids (which is active from late October to early December, and peaks somewhere around November 12) are long, spread-out showers with no well-defined peak. During the peak nights for the South Taurid meteor shower, you might see as many as five meteors per hour. But The American Meteor Society explains what – in some years – can be awesome about the Taurid meteor showers:

The Taurids (both branches) are rich in fireballs and are often responsible for increased number of fireball reports from September through November.

Fireballs are the name of the game for the Taurids.

Seeing a Taurid fireball – even if it’s just one – counts as a big thrill. And, by the way, a fireball is just another word for a particularly bright meteor.

Eliot Herman in Tuscon, Arizona, caught this bright Taurid on October 28, 2016. Go to his Flickr page if you want to see it larger. Nice colors!

On any given night, these rather slow-moving meteors produce the greatest numbers in the few hours after midnight. At that time, the moon will have set or will be close to setting. Because the waxing (increasing) moon will set an hour later with each passing night, you’ll have more moon-free viewing on November 2 and 3 than the two following nights (November 4 and 5).

So we’re guaranteed to have deliciously dark skies for the South Taurids in the wee hours after midnight tonight, to highlight any Taurid fireball that might come whizzing by.

Click here to find out when the moon sets in your sky, remembering to check the moonrise and moonset box.

You can see this meteor is radiating from the constellation Taurus the Bull. See that V-shaped pattern to the right of Orion? The three Belt stars of Orion point to it. That’s the Bull’s Face. Eliot Herman in Tucson caught this Taurid meteor, too, in 2015. The bright object was the moon! Thanks, Eliot.

The other Taurid shower – the North Taurids – should add a few more meteors to the mix from late night until dawn.

And again … the Taurid showers do not exhibit strong peaks. So if you’re clouded out tonight and tomorrow, no problem. Just keep watching. The two Taurid showers tend to overlap and to plateau in activity during the first few weeks in November.

If you trace the South Taurid meteors backwards, they all appear to radiate from the constellation Taurus the Bull. As always, you don’t have to identify a meteor shower’s radiant point to watch the meteor shower. Just lie back comfortably and look up, in the hours between midnight and dawn.

By the way, the constellation Taurus itself is full of interesting things to see such as the Pleiades star cluster, the V-shaped Hyades cluster with bright Aldebaran in its midst.

Just be aware … you don’t need to find Taurus to watch the Taurid shower, for these meteors streak all over the sky.

Bottom line: The annual South Taurid meteor shower has been going on throughout October, and now the North Taurids have started as well. The peaks of these showers aren’t well defined, but the South Taurids might be peaking in the first week of November, 2019. Watch for them.

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

EarthSky’s meteor shower guide for 2019

See it! Best photos of 2015 Taurid fireballs

from EarthSky https://ift.tt/2OmUq7U

Whoa! Check out this giant geode

A researcher stands inside the Pulpí geode, one of the largest documented geodes in the world, located at a depth of about 150 feet (50 meters) in a former silver mine in southeast Spain. Image via Hector Garrido.

Meet one of the largest documented geodes in the world – the Pulpí geode – discovered in 1999. It’s located deep within a mine in Spain, which is open to being viewed by tourists. The geode is a hollow, egg-shaped object, just like those you find in rock shops. But it’s 36 feet (11 meters) wide, like a room with crystal-paneled walls. Its individual crystals are up to two meters in size, and they’re so transparent they’re said to look like ice crystals. Scientists are continuing to study the Pulpí geode. A study published October 15, 2019 in the peer-reviewed journal Geology proposed that a slow and steady process involving temperature fluctuations grew the giant gypsum crystals inside it. Juan Manuel García-Ruiz is a professor at the Universidad de Granada in Spain and a study coauthor. He said at Phys.org:

To reveal their formation has been a very tough task because unlike in the case of the giant crystals of Naica in Mexico, where the hydrothermal system is still active, the large geode of Pulpí is a fossilized environment.

The scientists performed a study of the geology and geochemistry of the abandoned mine where the geode was found:

… including a detailed mapping of the underground mining works, which has been used to allow the tourist visits in the mine.

They found that the large crystals had trapped a few fluid inclusions, which gave the scientists information about conditions at the time the crystals formed. The team measured the sulfur and oxygen isotope ratios of those inclusions and found that the gypsum likely stabilized at a temperature of about 20 degrees Celsius (68 degrees Fahrenheit).

That was a clue to the crystals’ history. Most areas that have grown giant gypsum crystals are attached to inactive hydrothermal systems. However, the finding that the crystals stabilized at 20 degrees C. suggested they might have formed closer to Earth’s surface, where climate fluctuations might also have played a role.

Also, 20 degrees C. is lower than the maximum soluble temperature for gypsum of 45 degrees C. And – according to these scientists – that fact suggested the crystals had grown over a long period of time from a slow, steady drip of a concentrated calcium sulfate solution. An article in EOS explained:

With a relatively stable temperature, many smaller gypsum crystals dissolved to form fewer, larger ones in a process called Ostwald ripening.

García-Ruiz said:

This is somewhat like the temperature cycles in crystal quality control in industrial processes.

Read more about the study via EOS: Giant geode grew slow and steady

Read more about the study via Phys.org: The giant geode of Pulpí

The researchers found that the rock that encompasses the geode is made of layered carbonate from the Triassic period (201–251 million years ago). The geode, however, is only between 60 thousand and 2 million years old. Lines in the Pulpí geode’s clear gypsum crystals track growth periods. Image via Hector Garrido.

As for visiting the geode, we snagged the comment and photos below from a page at TripAdvisor.com. It looks like a very interesting place to go!

A tunnel, in the mine system leading to the geode of Pulpí. Image via TripAdvisor.com.

Apparently, tourists can get up close and personal with the geode, too. Image via TripAdvisor.com.

Bottom line: Scientists recently studied the formation of the giant crystals inside the geode of Pulpí, located in a mine in Spain. They found that temperature fluctuations – maybe from climate or maybe from geothermal systems – amplified a natural process that grew the crystals, ripening them over thousands of years.

Source: The origin of large gypsum crystals in the Geode of Pulpí (Almería, Spain)

from EarthSky https://ift.tt/329nczK

A researcher stands inside the Pulpí geode, one of the largest documented geodes in the world, located at a depth of about 150 feet (50 meters) in a former silver mine in southeast Spain. Image via Hector Garrido.

Meet one of the largest documented geodes in the world – the Pulpí geode – discovered in 1999. It’s located deep within a mine in Spain, which is open to being viewed by tourists. The geode is a hollow, egg-shaped object, just like those you find in rock shops. But it’s 36 feet (11 meters) wide, like a room with crystal-paneled walls. Its individual crystals are up to two meters in size, and they’re so transparent they’re said to look like ice crystals. Scientists are continuing to study the Pulpí geode. A study published October 15, 2019 in the peer-reviewed journal Geology proposed that a slow and steady process involving temperature fluctuations grew the giant gypsum crystals inside it. Juan Manuel García-Ruiz is a professor at the Universidad de Granada in Spain and a study coauthor. He said at Phys.org:

To reveal their formation has been a very tough task because unlike in the case of the giant crystals of Naica in Mexico, where the hydrothermal system is still active, the large geode of Pulpí is a fossilized environment.

The scientists performed a study of the geology and geochemistry of the abandoned mine where the geode was found:

… including a detailed mapping of the underground mining works, which has been used to allow the tourist visits in the mine.

They found that the large crystals had trapped a few fluid inclusions, which gave the scientists information about conditions at the time the crystals formed. The team measured the sulfur and oxygen isotope ratios of those inclusions and found that the gypsum likely stabilized at a temperature of about 20 degrees Celsius (68 degrees Fahrenheit).

That was a clue to the crystals’ history. Most areas that have grown giant gypsum crystals are attached to inactive hydrothermal systems. However, the finding that the crystals stabilized at 20 degrees C. suggested they might have formed closer to Earth’s surface, where climate fluctuations might also have played a role.

Also, 20 degrees C. is lower than the maximum soluble temperature for gypsum of 45 degrees C. And – according to these scientists – that fact suggested the crystals had grown over a long period of time from a slow, steady drip of a concentrated calcium sulfate solution. An article in EOS explained:

With a relatively stable temperature, many smaller gypsum crystals dissolved to form fewer, larger ones in a process called Ostwald ripening.

García-Ruiz said:

This is somewhat like the temperature cycles in crystal quality control in industrial processes.

Read more about the study via EOS: Giant geode grew slow and steady

Read more about the study via Phys.org: The giant geode of Pulpí

The researchers found that the rock that encompasses the geode is made of layered carbonate from the Triassic period (201–251 million years ago). The geode, however, is only between 60 thousand and 2 million years old. Lines in the Pulpí geode’s clear gypsum crystals track growth periods. Image via Hector Garrido.

As for visiting the geode, we snagged the comment and photos below from a page at TripAdvisor.com. It looks like a very interesting place to go!

A tunnel, in the mine system leading to the geode of Pulpí. Image via TripAdvisor.com.

Apparently, tourists can get up close and personal with the geode, too. Image via TripAdvisor.com.

Bottom line: Scientists recently studied the formation of the giant crystals inside the geode of Pulpí, located in a mine in Spain. They found that temperature fluctuations – maybe from climate or maybe from geothermal systems – amplified a natural process that grew the crystals, ripening them over thousands of years.

Source: The origin of large gypsum crystals in the Geode of Pulpí (Almería, Spain)

from EarthSky https://ift.tt/329nczK

News digest – liver cancer death rates, snacking culture, barriers to screening and fact checking NHS claims

Increase in liver cancer deaths partly down to rising obesity

Our new stats reveal deaths from liver cancer in the UK have risen by around 80% between 2007 and 2017. The Guardian reports that while rising levels of obesity and the fact that more people are being diagnosed are both contributing factors, liver cancer survival is notoriously low. Our press release has the full story.

Liver cancer death rates have increased by around 50% in the last decade, and have tripled since records began. Progress has been made, but there’s more to do, which is why we’re funding more research into better and more effective treatments. Learn more: https://t.co/hwCCuTbyHb pic.twitter.com/4KJ9hCQfci

— Cancer Research UK (@CR_UK) November 1, 2019

High levels of two hormones increase prostate cancer risk

New research suggests a link between men with higher levels of testosterone and a certain growth hormone in their blood and a greater risk of developing prostate cancer. The study included more than 200,000 men, but while these findings help us understand the disease better, more research is needed before we can use this information to help more men survive the disease. Read more about this on ITV News.

‘Britain must become more like France’ to tackle obesity, says top UK doctor

According to Government findings, only 5 out of 100 children in Paris are obese compared to 22 in 100 in London. We don’t know exactly what’s behind the difference, but as highlighted by Dame Sally Davies in The Telegraph, snacking habits do differ in the two countries.

Experimental cancer drug show promise

An experimental cancer drug, which targets a common genetic fault found in cancer cells, has shown early signs of promise in people with lung cancer. The new drug, AMG 510, shrunk tumours in two of the four patients tested. It’s a positive step towards targeting a previously ‘undruggable’ protein that drives cancer growth, but it’s still early days. The drug now needs to be tested in much larger groups. Mail Online has this one.

Pakistani woman hid breast cancer from relatives because of fear of stigma

Saj Dar hid a cancerous lump from her relatives for weeks, for fear of how they would take the news. And data from Macmillan suggests she’s not alone. Statistics show the uptake of cancer screening is much lower among black and Asian people than in the Caucasian population. This is thought to be due to lack of conversation, language barriers and cultural sensitivities in minority communities. Read more of Saj’s story at BBC News.

The future of AI could revolutionise drug discovery

Right now, only around 1 in 7 of drugs successfully go from being tested in mid-sized, phase 2 trials to being approved for patient use. But researchers hope this can be significantly improved with the help of artificial intelligence (AI). Learn more about AI’s potential for drug discovery in this Stat News article.

And finally…

If this week’s Prime Minister’s Questions are anything to go by, the NHS and its future could become a key issue in the upcoming election campaign. BBC News takes a closer look at some of the claims made during the exchange, including pledges for new hospitals and recognising the rise in waiting times for cancer treatments.

from Cancer Research UK – Science blog https://ift.tt/2qdyd5Z

Increase in liver cancer deaths partly down to rising obesity

Our new stats reveal deaths from liver cancer in the UK have risen by around 80% between 2007 and 2017. The Guardian reports that while rising levels of obesity and the fact that more people are being diagnosed are both contributing factors, liver cancer survival is notoriously low. Our press release has the full story.

Liver cancer death rates have increased by around 50% in the last decade, and have tripled since records began. Progress has been made, but there’s more to do, which is why we’re funding more research into better and more effective treatments. Learn more: https://t.co/hwCCuTbyHb pic.twitter.com/4KJ9hCQfci

— Cancer Research UK (@CR_UK) November 1, 2019

High levels of two hormones increase prostate cancer risk

New research suggests a link between men with higher levels of testosterone and a certain growth hormone in their blood and a greater risk of developing prostate cancer. The study included more than 200,000 men, but while these findings help us understand the disease better, more research is needed before we can use this information to help more men survive the disease. Read more about this on ITV News.

‘Britain must become more like France’ to tackle obesity, says top UK doctor

According to Government findings, only 5 out of 100 children in Paris are obese compared to 22 in 100 in London. We don’t know exactly what’s behind the difference, but as highlighted by Dame Sally Davies in The Telegraph, snacking habits do differ in the two countries.

Experimental cancer drug show promise

An experimental cancer drug, which targets a common genetic fault found in cancer cells, has shown early signs of promise in people with lung cancer. The new drug, AMG 510, shrunk tumours in two of the four patients tested. It’s a positive step towards targeting a previously ‘undruggable’ protein that drives cancer growth, but it’s still early days. The drug now needs to be tested in much larger groups. Mail Online has this one.

Pakistani woman hid breast cancer from relatives because of fear of stigma

Saj Dar hid a cancerous lump from her relatives for weeks, for fear of how they would take the news. And data from Macmillan suggests she’s not alone. Statistics show the uptake of cancer screening is much lower among black and Asian people than in the Caucasian population. This is thought to be due to lack of conversation, language barriers and cultural sensitivities in minority communities. Read more of Saj’s story at BBC News.

The future of AI could revolutionise drug discovery

Right now, only around 1 in 7 of drugs successfully go from being tested in mid-sized, phase 2 trials to being approved for patient use. But researchers hope this can be significantly improved with the help of artificial intelligence (AI). Learn more about AI’s potential for drug discovery in this Stat News article.

And finally…

If this week’s Prime Minister’s Questions are anything to go by, the NHS and its future could become a key issue in the upcoming election campaign. BBC News takes a closer look at some of the claims made during the exchange, including pledges for new hospitals and recognising the rise in waiting times for cancer treatments.

from Cancer Research UK – Science blog https://ift.tt/2qdyd5Z

Small asteroid C0PPEV1 paid a heavy price for almost striking Earth yesterday

Artist’s concept of an asteroid approaching Earth.

I happened to catch this post on Twitter this morning, from Tony Dunn (@tony873004), an amateur astronomer and physics teacher who knows how to create simulations of asteroids’ orbits. Tony tweeted:

Newly-discovered #asteroid C0PPEV1 paid a heavy price for almost striking Earth this morning.
Earth's gravity bent its trajectory, sending its aphelion out to the asteroid belt.https://t.co/q4qKuaUHjb pic.twitter.com/vzx5zpxGBG

— Tony Dunn (@tony873004) October 31, 2019

He’s talking about near-Earth asteroid C0PPEV1, spotted in the early morning hours of October 31, 2019 by the Catalina Sky Survey in Arizona, and by other observatories soon afterwards. This small asteroid came incredibly close yesterday. According to simulations, it passed above southern Africa within 3,852 miles (6,200 km) at the moment of closest approach, around 13:45 UTC (9:45 a.m. EDT; translate UTC to your time) on October 31. That’s well within the orbit of many telecommunications satellites (geosynchronous orbits above Earth, those causing satellites to remain over a single spot on Earth’s surface, are 22,236 miles – or 35,786 km – high). It was so close that CNET reported:

According to data from these early observations, the asteroid came closer to the surface of our planet (without actually colliding with our atmosphere) than any other close approach in NASA’s database of known near-Earth objects.

EarthSky has not confirmed that C0PPEV1 came closer to Earth than any other known near-Earth object.

But we can confirm that small asteroids like C0PPEV1 do sometimes come close and, in fact, frequently enter Earth’s atmosphere. For example, the Nuclear Test Ban Treaty Organization, which operates a network of sensors that monitors Earth around the clock listening for the infrasound signature of nuclear detonations, said in 2014 that it had recorded 26 atom-bomb-scale asteroid impacts to Earth’s atmosphere since 2000.

We can also confirm that a small asteroid coming close to Earth is indeed likely to have its orbit affected. Such an effect is called a gravity assist, and it’s used by NASA and other space agencies to help propel our spacecraft toward hard-to-reach places in the solar system.

Read more: Spooky Halloween asteroid flyby one of the closest near misses ever seen

Read more: Whoa! 26 atom-bomb-scale asteroid impacts since 2000

Bottom line: Earth’s gravity bent the trajectory of small asteroid C0PPEV1 – which passed exceedingly close to Earth on October 31, 2019 – causing its aphelion, or farthest point ib orbit around the sun, to shift out in the asteroid belt between Jupiter and Mars. So long, C0PPEV1!

from EarthSky https://ift.tt/339EuOS

Artist’s concept of an asteroid approaching Earth.

I happened to catch this post on Twitter this morning, from Tony Dunn (@tony873004), an amateur astronomer and physics teacher who knows how to create simulations of asteroids’ orbits. Tony tweeted:

Newly-discovered #asteroid C0PPEV1 paid a heavy price for almost striking Earth this morning.
Earth's gravity bent its trajectory, sending its aphelion out to the asteroid belt.https://t.co/q4qKuaUHjb pic.twitter.com/vzx5zpxGBG

— Tony Dunn (@tony873004) October 31, 2019

He’s talking about near-Earth asteroid C0PPEV1, spotted in the early morning hours of October 31, 2019 by the Catalina Sky Survey in Arizona, and by other observatories soon afterwards. This small asteroid came incredibly close yesterday. According to simulations, it passed above southern Africa within 3,852 miles (6,200 km) at the moment of closest approach, around 13:45 UTC (9:45 a.m. EDT; translate UTC to your time) on October 31. That’s well within the orbit of many telecommunications satellites (geosynchronous orbits above Earth, those causing satellites to remain over a single spot on Earth’s surface, are 22,236 miles – or 35,786 km – high). It was so close that CNET reported:

According to data from these early observations, the asteroid came closer to the surface of our planet (without actually colliding with our atmosphere) than any other close approach in NASA’s database of known near-Earth objects.

EarthSky has not confirmed that C0PPEV1 came closer to Earth than any other known near-Earth object.

But we can confirm that small asteroids like C0PPEV1 do sometimes come close and, in fact, frequently enter Earth’s atmosphere. For example, the Nuclear Test Ban Treaty Organization, which operates a network of sensors that monitors Earth around the clock listening for the infrasound signature of nuclear detonations, said in 2014 that it had recorded 26 atom-bomb-scale asteroid impacts to Earth’s atmosphere since 2000.

We can also confirm that a small asteroid coming close to Earth is indeed likely to have its orbit affected. Such an effect is called a gravity assist, and it’s used by NASA and other space agencies to help propel our spacecraft toward hard-to-reach places in the solar system.

Read more: Spooky Halloween asteroid flyby one of the closest near misses ever seen

Read more: Whoa! 26 atom-bomb-scale asteroid impacts since 2000

Bottom line: Earth’s gravity bent the trajectory of small asteroid C0PPEV1 – which passed exceedingly close to Earth on October 31, 2019 – causing its aphelion, or farthest point ib orbit around the sun, to shift out in the asteroid belt between Jupiter and Mars. So long, C0PPEV1!

from EarthSky https://ift.tt/339EuOS