Full moon subdues North Taurid meteor peak

The full moon is sweeping through Taurus around November 11-13, 2019. On the same evenings, the North Taurid meteor shower – which radiates from this constellation – is reaching its peak.

Full moon comes on November 12, 2019, as the moon is sweeping through the constellation Taurus the Bull. As viewed from all parts of Earth, the full moon will light up the nighttime from dusk until dawn. This bright moon comes at the wrong time for meteor-watching enthusiasts, because – on the evening of November 11, into the morning of November 12 – the long-lasting North Taurid meteor shower also reaches a peak.

Read more: Want more about the meteor shower? Try this article: North Taurid meteors in moonlight

In North America, we often call the November full moon the Beaver Moon or Frost Moon. In the Southern Hemisphere, where’s it’s now the springtime season, this November full moon is more associated with springtime flowers than with late autumn frosts.

Although the moon might look full to the eye for two to three nights in a row, astronomers say the moon is truly full at a well-defined instant. Full moon occurs when the moon is precisely 180 degrees opposite the sun in ecliptic longitude. In other words, the elongation between the moon and sun is 180 degrees at full moon.

Visit unitarium.com to find out the present moon-sun elongation, remembering that a positive number refers to a waxing moon, whereas a negative number indicates a waning moon.

The full moon arrives on November 12, 2019, at 13:34 Universal Time (UTC). Although the instant of full moon happens at the same time worldwide, the clock differs by time zone. For us in the United States, the full moon occurs on November 12, at 8:34 a.m. Eastern Time, 7:34 a.m. Central Time, 6:34 a.m. Mountain Time, 5:34 a.m. Pacific Time, 4:34 a.m. Alaskan Time and 3:34 a.m. Hawaiian Time.

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

The day and night sides of Earth at full moon (November 12, 2019, at 13:34 Universal Time). The shadow line at left (running through North America) depicts sunrise (moonset) November 12, whereas the shadow line at right (crossing eastern Europe and the Middle East) represents sunset (moonrise) November 12. Image via EarthView.

Bottom line: Full moon comes on November 12, 2019, as the moon is sweeping through the constellation Taurus the Bull. This full moon comes on the peak night of the North Taurid meteor shower.

from EarthSky https://ift.tt/32y6WsA

The full moon is sweeping through Taurus around November 11-13, 2019. On the same evenings, the North Taurid meteor shower – which radiates from this constellation – is reaching its peak.

Full moon comes on November 12, 2019, as the moon is sweeping through the constellation Taurus the Bull. As viewed from all parts of Earth, the full moon will light up the nighttime from dusk until dawn. This bright moon comes at the wrong time for meteor-watching enthusiasts, because – on the evening of November 11, into the morning of November 12 – the long-lasting North Taurid meteor shower also reaches a peak.

Read more: Want more about the meteor shower? Try this article: North Taurid meteors in moonlight

In North America, we often call the November full moon the Beaver Moon or Frost Moon. In the Southern Hemisphere, where’s it’s now the springtime season, this November full moon is more associated with springtime flowers than with late autumn frosts.

Although the moon might look full to the eye for two to three nights in a row, astronomers say the moon is truly full at a well-defined instant. Full moon occurs when the moon is precisely 180 degrees opposite the sun in ecliptic longitude. In other words, the elongation between the moon and sun is 180 degrees at full moon.

Visit unitarium.com to find out the present moon-sun elongation, remembering that a positive number refers to a waxing moon, whereas a negative number indicates a waning moon.

The full moon arrives on November 12, 2019, at 13:34 Universal Time (UTC). Although the instant of full moon happens at the same time worldwide, the clock differs by time zone. For us in the United States, the full moon occurs on November 12, at 8:34 a.m. Eastern Time, 7:34 a.m. Central Time, 6:34 a.m. Mountain Time, 5:34 a.m. Pacific Time, 4:34 a.m. Alaskan Time and 3:34 a.m. Hawaiian Time.

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

The day and night sides of Earth at full moon (November 12, 2019, at 13:34 Universal Time). The shadow line at left (running through North America) depicts sunrise (moonset) November 12, whereas the shadow line at right (crossing eastern Europe and the Middle East) represents sunset (moonrise) November 12. Image via EarthView.

Bottom line: Full moon comes on November 12, 2019, as the moon is sweeping through the constellation Taurus the Bull. This full moon comes on the peak night of the North Taurid meteor shower.

from EarthSky https://ift.tt/32y6WsA

November 12 full moon is the Beaver or Frosty Moon

Maggie NY wrote, “November’s Beaver Moon over New York.” Thanks, Maggie! Check out the moon photos at EarthSky Community Photos or submit your own.

The moon appears full to the eye for two to three nights. However, astronomers regard the moon as full at a precisely defined instant, when the moon is exactly 180 degrees opposite the sun in ecliptic longitude. That full moon instant comes in the early morning hours Tuesday, November 12, 2019, according to clocks in the Americas (8:34 a.m. Eastern on November 12, or 13:34 UTC; translate UTC to your time).

Sometimes the November full moon is the Hunter’s Moon, but not this year. By tradition, the Harvest Moon is the full moon closest to the September equinox. This year’s Harvest Moon came early, on September 13, 2019. Also by tradition, the Hunter’s Moon is the full moon following the Harvest Moon. So this year’s Hunter’s Moon was the full moon of October 12-13.

Never fear, though. November’s full moon has names all its own. The full moon of November is called the Frosty Moon or Beaver Moon.

Read more: What are the full moon names?

This full moon will interfere with the peak of the North Taurid meteor shower. It comes as the moon is sweeping through the constellation Taurus the Bull, the same constellation from which the North Taurid meteors radiate.

Read more: Full moon to subdue peak of North Taurid meteors

A kiss under the full moon of November 3, 2017, via our friend Steven Sweet of Lunar 101-Moon Book. He was at Port Credit, a neighbourhood in the city of Mississauga, Ontario, Canada … at the mouth of the Credit River on the north shore of Lake Ontario.

Why does a full moon look full? Remember that half the moon is always illuminated by the sun. That lighted half is the moon’s day side. In order to appear full to us on Earth, we have to see the entire day side of the moon. That happens only when the moon is opposite the sun in our sky. So a full moon looks full because it’s opposite the sun.

That’s also why every full moon rises in the east around sunset – climbs highest up for the night midway between sunset and sunrise (around midnight) – and sets around sunrise. Stand outside tonight around sunset and look for the moon. Sun going down while the moon is coming up? That’s a full moon, or close to one.

Just be aware that the moon will look full for at least a couple of night around the instant of full moon.

A full moon is opposite the sun. We see all of its dayside. Illustration via Bob King.

Often, you’ll find two different dates on calendars for the date of full moon. That’s because some calendars list moon phases in Coordinated Universal Time, also called Universal Time Coordinated (UTC). And other calendars list moon phases in local time, a clock time of a specific place, usually the place that made and distributed the calendars. Translate UTC to your local time.

Want to know the instant of full moon in your part of the world, as well as the moonrise and moonset times? Visit the Sunrise Sunset Calendars site, remembering to check the moon phases plus moonrise and moonset boxes.

If a full moon is opposite the sun, why doesn’t Earth’s shadow fall on the moon at every full moon? The reason is that the moon’s orbit is titled by 5.1 degrees with respect to Earth’s orbit around the sun. At every full moon, Earth’s shadow sweeps near the moon. But, in most months, there’s no eclipse.

A full moon normally passes above or below Earth’s shadow, with no eclipse. Illustration by Bob King.

As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.

New moon
Waxing crescent moon
First quarter moon
Waxing gibbous moon
Full moon
Waning gibbous moon
Last quarter moon
Waning crescent moon

Bottom line: Full moon – when the moon is most opposite the sun for this month – falls on Tuesday, November 12, 2019, according to clocks in the Americas (8:34 a.m. Eastern on November 12, or 13:34 UTC; translate UTC to your time).

Read more: 4 keys to understanding moon phases

Read more: What are the full moon names?

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

Maggie NY wrote, “November’s Beaver Moon over New York.” Thanks, Maggie! Check out the moon photos at EarthSky Community Photos or submit your own.

The moon appears full to the eye for two to three nights. However, astronomers regard the moon as full at a precisely defined instant, when the moon is exactly 180 degrees opposite the sun in ecliptic longitude. That full moon instant comes in the early morning hours Tuesday, November 12, 2019, according to clocks in the Americas (8:34 a.m. Eastern on November 12, or 13:34 UTC; translate UTC to your time).

Sometimes the November full moon is the Hunter’s Moon, but not this year. By tradition, the Harvest Moon is the full moon closest to the September equinox. This year’s Harvest Moon came early, on September 13, 2019. Also by tradition, the Hunter’s Moon is the full moon following the Harvest Moon. So this year’s Hunter’s Moon was the full moon of October 12-13.

Never fear, though. November’s full moon has names all its own. The full moon of November is called the Frosty Moon or Beaver Moon.

Read more: What are the full moon names?

This full moon will interfere with the peak of the North Taurid meteor shower. It comes as the moon is sweeping through the constellation Taurus the Bull, the same constellation from which the North Taurid meteors radiate.

Read more: Full moon to subdue peak of North Taurid meteors

A kiss under the full moon of November 3, 2017, via our friend Steven Sweet of Lunar 101-Moon Book. He was at Port Credit, a neighbourhood in the city of Mississauga, Ontario, Canada … at the mouth of the Credit River on the north shore of Lake Ontario.

Why does a full moon look full? Remember that half the moon is always illuminated by the sun. That lighted half is the moon’s day side. In order to appear full to us on Earth, we have to see the entire day side of the moon. That happens only when the moon is opposite the sun in our sky. So a full moon looks full because it’s opposite the sun.

That’s also why every full moon rises in the east around sunset – climbs highest up for the night midway between sunset and sunrise (around midnight) – and sets around sunrise. Stand outside tonight around sunset and look for the moon. Sun going down while the moon is coming up? That’s a full moon, or close to one.

Just be aware that the moon will look full for at least a couple of night around the instant of full moon.

A full moon is opposite the sun. We see all of its dayside. Illustration via Bob King.

Often, you’ll find two different dates on calendars for the date of full moon. That’s because some calendars list moon phases in Coordinated Universal Time, also called Universal Time Coordinated (UTC). And other calendars list moon phases in local time, a clock time of a specific place, usually the place that made and distributed the calendars. Translate UTC to your local time.

Want to know the instant of full moon in your part of the world, as well as the moonrise and moonset times? Visit the Sunrise Sunset Calendars site, remembering to check the moon phases plus moonrise and moonset boxes.

If a full moon is opposite the sun, why doesn’t Earth’s shadow fall on the moon at every full moon? The reason is that the moon’s orbit is titled by 5.1 degrees with respect to Earth’s orbit around the sun. At every full moon, Earth’s shadow sweeps near the moon. But, in most months, there’s no eclipse.

A full moon normally passes above or below Earth’s shadow, with no eclipse. Illustration by Bob King.

As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.

New moon
Waxing crescent moon
First quarter moon
Waxing gibbous moon
Full moon
Waning gibbous moon
Last quarter moon
Waning crescent moon

Bottom line: Full moon – when the moon is most opposite the sun for this month – falls on Tuesday, November 12, 2019, according to clocks in the Americas (8:34 a.m. Eastern on November 12, or 13:34 UTC; translate UTC to your time).

Read more: 4 keys to understanding moon phases

Read more: What are the full moon names?

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Stunning view inside a young moon crater

View larger. | Giordano Bruno Crater as seen directly from overhead. Image via NASA/GSFC/Arizona State University/LROC.

You might think of the moon as gray, rocky and dusty, a bleak and desolate world. But in fact, the moon is a beautiful place in its own way, and does offer some incredible scenery with its many craters and mountains. This view inside a crater from NASA’s Lunar Reconnaissance Orbiter (LRO) is a great example, and as the article title says, spectacular.

The stunning oblique view inside a young crater in the top image shows how otherworldly yet starkly and serenely majestic the moon can be.

These photos were taken by LRO in August 2017, from an altitude of 70 miles (113 km). Giordano Bruno Crater is one of the youngest large craters on the moon, 13 miles (21 km) in diameter, and located at 35.97°N, 102.89°E. There is a lot of surface brightness (albedo) contrast visible, as the sun was high above the horizon at the time, and the only shadows seen are from steep cliffs and large boulders.

The steep cliff – the inside wall of the crater – rises a staggering 9,843 feet (3,000 meters) above the bottom of the crater, where you see a large melt pool of ancient liquified rock, leftover from the huge impact that created the crater. Can you imagine yourself standing there and gazing up at this massive crater wall in front of you?

A wider view of Giordano Bruno Crater from LRO. Image via NASA/GSFC/Arizona State University/LROC.

Detailed view of an impact melt flow inside Giordano Bruno Crater. Image via NASA/GSFC/Arizona State University/LROC.

Dark rubbly material on the bottom of Giordano-Bruno-Crater. Image via NASA/GSFC/Arizona State University/LROC.

Close-up view of a steep cliff on the inside crater wall of Giordano Bruno Crater, as seen by Lunar Reconnaissance Orbiter (LRO) in August 2017. Image via NASA/GSFC/Arizona State University/LROC.

The impacts that create craters like these are powerful. Here, a large rocky asteroid or meteor – up to 1.2 miles (2 km) in size – slammed into the moon about ten times faster than a speeding bullet. As typically happens, the impacting rock created a hole in the ground much larger than the rock itself. A tremendous amount of heat and pressure are released during the impact, which melts a lot of the rock. This created a temporary pool of melted rock – the melt pool – which sloshed and flowed, almost like water. Over time, the melted rock cooled and solidified, leaving the darker-colored melt pool we see today. You can still see where the melted rock flowed across the crater floor, filling depressions.

There is also some interesting dark, rubbly material on the bottom floor of the crater, which may be from basaltic dikes or perhaps impact melt glass, called impactite. Could it be similar to what China’s Yutu-2 rover recently found on the far side of the moon?

It isn’t known yet exactly how old the crater is, but the well-preserved forms of the impact melt flows and the sparsity of other smaller craters inside it show that it is quite young geologically-speaking, probably less than 10 million years.

Some of the LRO images of this crater have a pixel scale as small as 1.6 to 1.8 meters. When in its lowest orbit, LRO obtained images of the crater with an impressive resolution of 50 centimeters.

LRO was launched on June 18, 2009 and has been returning a wealth of science data ever since, as well as stunning views like these ones.

Artist’s illustration of the Lunar Reconnaissance Orbiter (LRO) near the moon. Image via NASA.

Bottom line: This is a spectacular view inside a younger crater on the moon, as seen by NASA’s Lunar Reconnaissance Orbiter.

Via LROC

from EarthSky https://ift.tt/34MOr55

View larger. | Giordano Bruno Crater as seen directly from overhead. Image via NASA/GSFC/Arizona State University/LROC.

You might think of the moon as gray, rocky and dusty, a bleak and desolate world. But in fact, the moon is a beautiful place in its own way, and does offer some incredible scenery with its many craters and mountains. This view inside a crater from NASA’s Lunar Reconnaissance Orbiter (LRO) is a great example, and as the article title says, spectacular.

The stunning oblique view inside a young crater in the top image shows how otherworldly yet starkly and serenely majestic the moon can be.

These photos were taken by LRO in August 2017, from an altitude of 70 miles (113 km). Giordano Bruno Crater is one of the youngest large craters on the moon, 13 miles (21 km) in diameter, and located at 35.97°N, 102.89°E. There is a lot of surface brightness (albedo) contrast visible, as the sun was high above the horizon at the time, and the only shadows seen are from steep cliffs and large boulders.

The steep cliff – the inside wall of the crater – rises a staggering 9,843 feet (3,000 meters) above the bottom of the crater, where you see a large melt pool of ancient liquified rock, leftover from the huge impact that created the crater. Can you imagine yourself standing there and gazing up at this massive crater wall in front of you?

A wider view of Giordano Bruno Crater from LRO. Image via NASA/GSFC/Arizona State University/LROC.

Detailed view of an impact melt flow inside Giordano Bruno Crater. Image via NASA/GSFC/Arizona State University/LROC.

Dark rubbly material on the bottom of Giordano-Bruno-Crater. Image via NASA/GSFC/Arizona State University/LROC.

Close-up view of a steep cliff on the inside crater wall of Giordano Bruno Crater, as seen by Lunar Reconnaissance Orbiter (LRO) in August 2017. Image via NASA/GSFC/Arizona State University/LROC.

The impacts that create craters like these are powerful. Here, a large rocky asteroid or meteor – up to 1.2 miles (2 km) in size – slammed into the moon about ten times faster than a speeding bullet. As typically happens, the impacting rock created a hole in the ground much larger than the rock itself. A tremendous amount of heat and pressure are released during the impact, which melts a lot of the rock. This created a temporary pool of melted rock – the melt pool – which sloshed and flowed, almost like water. Over time, the melted rock cooled and solidified, leaving the darker-colored melt pool we see today. You can still see where the melted rock flowed across the crater floor, filling depressions.

There is also some interesting dark, rubbly material on the bottom floor of the crater, which may be from basaltic dikes or perhaps impact melt glass, called impactite. Could it be similar to what China’s Yutu-2 rover recently found on the far side of the moon?

It isn’t known yet exactly how old the crater is, but the well-preserved forms of the impact melt flows and the sparsity of other smaller craters inside it show that it is quite young geologically-speaking, probably less than 10 million years.

Some of the LRO images of this crater have a pixel scale as small as 1.6 to 1.8 meters. When in its lowest orbit, LRO obtained images of the crater with an impressive resolution of 50 centimeters.

LRO was launched on June 18, 2009 and has been returning a wealth of science data ever since, as well as stunning views like these ones.

Artist’s illustration of the Lunar Reconnaissance Orbiter (LRO) near the moon. Image via NASA.

Bottom line: This is a spectacular view inside a younger crater on the moon, as seen by NASA’s Lunar Reconnaissance Orbiter.

Via LROC

from EarthSky https://ift.tt/34MOr55

Did ancient Earth life escape our solar system?

Bacteria-like fossilized structures in the Martian meteorite ALH84001. Image via NASA/Wikimedia/Scientific American.

Panspermia is the theory that asteroids, meteors or comets can carry microorganisms from one planetary system to another, and that such a process – perhaps microbes coming from Mars – may have helped life first develop on Earth. But could the reverse also be possible? Could microbial life be launched from Earth by asteroid impacts? Could that earthly life then end up leaving our solar system altogether? A new research paper by theoretical physicist Abraham (Avi) Loeb at Harvard University suggests that there could have been many such events over the lifetime of the Earth so far. He also just wrote a thought-provoking opinion article in Scientific American discussing this fascinating possibility.

The new peer-reviewed study was submitted to arXiv on October 14, 2019.

From the paper:

Exporting terrestrial life out of the solar system requires a process that both embeds microbes in boulders and ejects those boulders out of the solar system. We explore the possibility that Earth-grazing long-period comets and interstellar objects could export life from Earth by collecting microbes from the atmosphere and receiving a gravitational slingshot effect from the Earth. We estimate the total number of exportation events over the lifetime of the Earth to be about 1 – 10 for long-period comets and about 1 – 50 for interstellar objects. If life existed above an altitude of 100 km, then the number is dramatically increased up to about 100,000 exportation events over Earth’s lifetime.

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

The panspermia theory says that microbes could be transported through the galaxy in asteroids, meteors or comets, and may even help explain the beginnings of life on Earth. A new study by Abraham (Avi) Loeb says that it is also possible that microscopic life could have been blasted off the Earth multiple times in the ancient past, potentially even escaping our solar system. Image via Astrobiology at NASA.

The idea that earthly life could be exported to other places in the solar system or even beyond is a fascinating one. But has it really happened?

As Loeb noted, in most cases asteroid impacts wouldn’t be able to send rocks outside the solar system, but some of them could still make that journey with the help of other planets:

Most asteroid impacts are not powerful enough to eject terrestrial rocks with enough speed to leave the solar system. But many solar system bodies spend most of their time in the Oort Cloud, a sort of comet nursery that hovers, loosely bound to the sun, at distances up to 100,000 times farther out than Earth. Some of these bodies appear episodically as long-period comets with eccentric orbits that bring them close to the sun, where they can get gravitationally kicked by planets all the way out of the solar system, like a ball running through a pinball machine.

Bacillus subtilis is one type of microorganism that could survive being ejected into space by an asteroid impact. Image via Wickham Laboratories.

As well as microbes in rocks or soil, there are colonies of microbes in the atmosphere itself, at altitudes of about of 30 to 48 miles (48 to 77 kilometers). They could be “scooped up” by asteroids passing very close to Earth, but not impacting. This could even happen with asteroids that originated from beyond the solar system.

As Loeb also noted, microbes would be much better suited for surviving  being violently ejected into space inside a chunk of rock:

It is well known that fighter pilots can barely survive maneuvers with accelerations exceeding 10 gs, where g is the gravitational acceleration that binds us to Earth. But Earth-grazing objects would scoop microbes at accelerations of millions of gs. Could they survive the jolt? Possibly! Microbes and other tiny organisms such as Bacillus subtilis, Caenorhabditis elegans, Deinococcus radiodurans, Escherichia coli and Paracoccus denitrificans have been shown to live through accelerations just one order of magnitude smaller. As it turns out, these mini astronauts are far better suited for taking a space ride than our very best human pilots.

So, could Earth have spread life to other worlds? If any microbes from Earth ever did make this journey billions of years ago, could they have survived anywhere else in the solar system if they landed on another planet or moon? Not too likely, apart from maybe Mars (depending on how habitable it was at the time) or ice/ocean moons like Europa or Enceladus. But even on those moons, any microbes would just get dumped on the airless surfaces covered in ice. It’s doubtful that they could make their way down to the oceans below through the ice crusts unless perhaps they fell into a deep crack connected to water vapor geysers, as on Enceladus.

Theoretical physicist Abraham (Avi) Loeb. Image via Lane Turner/The Boston Globe via Getty Images/Harvard University.

If any life is ever discovered in the oceans of Europa or Enceladus, it’s more likely that it evolved there on its own. Also, if any microbes did make it out of the solar system completely, they would be traveling for millions or billions of years before encountering any other exoplanets or exomoons.

While it hasn’t been proven yet that life from Earth has previously traveled throughout – and perhaps even out of – the solar system, it is, according to Loeb, certainly a very interesting possibility.

Bottom line: A new paper by theoretical physicist Abraham (Avi) Loeb makes the case that microbes could have been ejected into space by asteroid impacts billions of years ago, in a reverse kind of panspermia.

Source: Exporting Terrestrial Life Out of the Solar System with Gravitational Slingshots of Earthgrazing Bodies

Via Scientific American

from EarthSky https://ift.tt/2Nzrdd2

Bacteria-like fossilized structures in the Martian meteorite ALH84001. Image via NASA/Wikimedia/Scientific American.

Panspermia is the theory that asteroids, meteors or comets can carry microorganisms from one planetary system to another, and that such a process – perhaps microbes coming from Mars – may have helped life first develop on Earth. But could the reverse also be possible? Could microbial life be launched from Earth by asteroid impacts? Could that earthly life then end up leaving our solar system altogether? A new research paper by theoretical physicist Abraham (Avi) Loeb at Harvard University suggests that there could have been many such events over the lifetime of the Earth so far. He also just wrote a thought-provoking opinion article in Scientific American discussing this fascinating possibility.

The new peer-reviewed study was submitted to arXiv on October 14, 2019.

From the paper:

Exporting terrestrial life out of the solar system requires a process that both embeds microbes in boulders and ejects those boulders out of the solar system. We explore the possibility that Earth-grazing long-period comets and interstellar objects could export life from Earth by collecting microbes from the atmosphere and receiving a gravitational slingshot effect from the Earth. We estimate the total number of exportation events over the lifetime of the Earth to be about 1 – 10 for long-period comets and about 1 – 50 for interstellar objects. If life existed above an altitude of 100 km, then the number is dramatically increased up to about 100,000 exportation events over Earth’s lifetime.

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

The panspermia theory says that microbes could be transported through the galaxy in asteroids, meteors or comets, and may even help explain the beginnings of life on Earth. A new study by Abraham (Avi) Loeb says that it is also possible that microscopic life could have been blasted off the Earth multiple times in the ancient past, potentially even escaping our solar system. Image via Astrobiology at NASA.

The idea that earthly life could be exported to other places in the solar system or even beyond is a fascinating one. But has it really happened?

As Loeb noted, in most cases asteroid impacts wouldn’t be able to send rocks outside the solar system, but some of them could still make that journey with the help of other planets:

Most asteroid impacts are not powerful enough to eject terrestrial rocks with enough speed to leave the solar system. But many solar system bodies spend most of their time in the Oort Cloud, a sort of comet nursery that hovers, loosely bound to the sun, at distances up to 100,000 times farther out than Earth. Some of these bodies appear episodically as long-period comets with eccentric orbits that bring them close to the sun, where they can get gravitationally kicked by planets all the way out of the solar system, like a ball running through a pinball machine.

Bacillus subtilis is one type of microorganism that could survive being ejected into space by an asteroid impact. Image via Wickham Laboratories.

As well as microbes in rocks or soil, there are colonies of microbes in the atmosphere itself, at altitudes of about of 30 to 48 miles (48 to 77 kilometers). They could be “scooped up” by asteroids passing very close to Earth, but not impacting. This could even happen with asteroids that originated from beyond the solar system.

As Loeb also noted, microbes would be much better suited for surviving  being violently ejected into space inside a chunk of rock:

It is well known that fighter pilots can barely survive maneuvers with accelerations exceeding 10 gs, where g is the gravitational acceleration that binds us to Earth. But Earth-grazing objects would scoop microbes at accelerations of millions of gs. Could they survive the jolt? Possibly! Microbes and other tiny organisms such as Bacillus subtilis, Caenorhabditis elegans, Deinococcus radiodurans, Escherichia coli and Paracoccus denitrificans have been shown to live through accelerations just one order of magnitude smaller. As it turns out, these mini astronauts are far better suited for taking a space ride than our very best human pilots.

So, could Earth have spread life to other worlds? If any microbes from Earth ever did make this journey billions of years ago, could they have survived anywhere else in the solar system if they landed on another planet or moon? Not too likely, apart from maybe Mars (depending on how habitable it was at the time) or ice/ocean moons like Europa or Enceladus. But even on those moons, any microbes would just get dumped on the airless surfaces covered in ice. It’s doubtful that they could make their way down to the oceans below through the ice crusts unless perhaps they fell into a deep crack connected to water vapor geysers, as on Enceladus.

Theoretical physicist Abraham (Avi) Loeb. Image via Lane Turner/The Boston Globe via Getty Images/Harvard University.

If any life is ever discovered in the oceans of Europa or Enceladus, it’s more likely that it evolved there on its own. Also, if any microbes did make it out of the solar system completely, they would be traveling for millions or billions of years before encountering any other exoplanets or exomoons.

While it hasn’t been proven yet that life from Earth has previously traveled throughout – and perhaps even out of – the solar system, it is, according to Loeb, certainly a very interesting possibility.

Bottom line: A new paper by theoretical physicist Abraham (Avi) Loeb makes the case that microbes could have been ejected into space by asteroid impacts billions of years ago, in a reverse kind of panspermia.

Source: Exporting Terrestrial Life Out of the Solar System with Gravitational Slingshots of Earthgrazing Bodies

Via Scientific American

from EarthSky https://ift.tt/2Nzrdd2

If you think the moon is an impediment to meteor-watching

View larger. | Feet of an owl perched on an all-sky meteor camera – around midnight on the morning of November 9, 2019 – via Eliot Herman of Tucson, Arizona.

Veteran meteor observer Eliot Herman has contributed many wonderful photos to EarthSky! Here’s one that didn’t come out as he’d planned, though. It’s an owl (“looks like a horned owl from the stripes,” he commented) perched on his automatic, all-sky camera. He wrote:

Meteor photography is really difficult if all that is visible is the rear end of an owl who decided to perch on the camera at midnight. The owl remained for about 5 minutes. The bright moon is enough of a problem to get good imagery but this really adds insult.

The twin stars of Gemini are visible between the toes on the lower left.

Fortunately, Eliot said, it looks as if the owl’s claws didn’t damage the lens, and it didn’t tip the camera.

Thank you, Eliot!

Read more: North Taurid meteors peak in moonlight

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View larger. | Feet of an owl perched on an all-sky meteor camera – around midnight on the morning of November 9, 2019 – via Eliot Herman of Tucson, Arizona.

Veteran meteor observer Eliot Herman has contributed many wonderful photos to EarthSky! Here’s one that didn’t come out as he’d planned, though. It’s an owl (“looks like a horned owl from the stripes,” he commented) perched on his automatic, all-sky camera. He wrote:

Meteor photography is really difficult if all that is visible is the rear end of an owl who decided to perch on the camera at midnight. The owl remained for about 5 minutes. The bright moon is enough of a problem to get good imagery but this really adds insult.

The twin stars of Gemini are visible between the toes on the lower left.

Fortunately, Eliot said, it looks as if the owl’s claws didn’t damage the lens, and it didn’t tip the camera.

Thank you, Eliot!

Read more: North Taurid meteors peak in moonlight

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Sweet bird

Photo by Bettina Berg.

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

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Photo by Bettina Berg.

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

from EarthSky https://ift.tt/36HzoeG

Moon halo over Pikes Peak

View larger. | Image via Joe Randall.

Wow! Joe Randall said he captured this gorgeous lunar halo on November 6, 2019 from a road overlooking Cascade, Colorado. He wrote:

The glow under the clouds to the left is Colorado Springs. And, of course, that is Pikes Peak in the center.

Thank you, Joe!

Read more: What makes a halo around the sun or moon?

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View larger. | Image via Joe Randall.

Wow! Joe Randall said he captured this gorgeous lunar halo on November 6, 2019 from a road overlooking Cascade, Colorado. He wrote:

The glow under the clouds to the left is Colorado Springs. And, of course, that is Pikes Peak in the center.

Thank you, Joe!

Read more: What makes a halo around the sun or moon?

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