Thursday, October 20, 2011 7:54:54 PM
Evidence of a Late Heavy Bombardment Occuring in Another Solar System
This artist's conception illustrates a storm of comets around a star near our own, called Eta Corvi. Evidence for this barrage comes from NASA's Spitzer Space Telescope, whose infrared detectors picked up indications that one or more comets was recently torn to shreds after colliding with a rocky body.
Image credit: NASA/JPL-Caltech
by Nancy Atkinson on October 19, 2011
Planetary scientists have not been able to agree that a turbulent period in our solar system’s history called the Late Heavy Bombardment actually occurred. But now, using observations from the Spitzer Space Telescope, scientists have detected activity resembling a similar type of event where icy bodies from the outer solar system are possibly pummeling rocky worlds closer to the star. This is the first time such activity has been seen in another planetary system.
“Where the comets are hitting the rocky bodies is in the habitable zone around this star, so not only are life-forming materials possibly being delivered to rocky worlds, but also in the right place for life as we know it to grow,” said Carey Lisse, senior research scientist at the Johns Hopkins University Applied Physics Laboratory. “This is similar to what happened to our own solar system during the Late Heavy Bombardment.”
Lisse spoke to journalists in a conference call from the Signposts of Planets [ http://science.gsfc.nasa.gov/667/conferences/signposts.html ] meeting taking place at Goddard Space Flight Center this week.
Spitzer observations showed a band of dust around the nearby, naked-eye-visible star called Eta Corvi, located in the constellation Corvus in northern sky. Within the band of warm dust, Spitzer’s infrared detectors saw the chemical fingerprints of water ice, organics and rock, which strongly matches the contents of an obliterated giant comet, suggesting a collision took place between a planet and one or more comets. Also detected was evidence for flash-frozen rocks, nanodiamonds and amorphous silica.
This dust is located 3 AU away from Eta Corvi, which is the “habitable zone” around that star, and is close enough to the star that Earth-like worlds could exist. Lisse said although it hasn’t been confirmed, researchers think there is a Neptune-like world and at least two other planets in this system. A bright, icy Kuiper Belt-like region located 3-4 times farther out than our own Kuiper Belt was discovered around Eta Corvi in 2005.
“This is very possibly a planet-rich system,” Lisse said.
The light signature emitted by the dust around Eta Corvi also resembles meteorites found on Earth. “We see a match between dust around Eta Corvi and the Almahata Sitta meteorites, which fell to Earth in Sudan in 2008,” Llisse said. “We can argue that the material around Eta Covi is rich in carbon and water, things that help life grow on Earth.”
The Eta Corvi system is approximately one billion years old, which the research team considers about the right age for such a bombardment.
No asteroidal dust was found in the disk around Eta Corvi.
“Asteroidal dust would look like it had been heated, and chemically and physically altered, and most of the water and carbon would be gone,” Lisse said. “This dust is very rich in water and carbon and the rocky components are very primitive and un-altered.”
Most planetary formation theories can’t account for such an intense period of bombardment in our own solar system so late in its history, but the Nice Model proposed in 2005 suggests the Late Heavy Bombardment was triggered when the giant planets in our solar system— which formed in a more compact configuration – rapidly migrated away from each other (and their orbital separations all increased), and a disk of small asteroids and comets that lay outside the orbits of the planets was destabilized, causing a sudden massive delivery of asteroids and comets to the inner solar system. The barrage scarred the Moon and produced large amounts of dust.
“We can see the process of this happening at Eta Corvi and can learn more about our own solar system, since we can’t go back in time,” Lisse said. “It’s very possible that the rain of comets and Kuiper Belt Objects brought life to Earth.”
Lisse and his team are not sure if one big comet or lots of smaller comets are pummeling the inner solar system. “It is probably many bodies, but we only see the effects of the largest ones,” he said.
Could this be an indication that a Late Heavy Bombardment happens in many solar systems? “It’s not clear whether this is an atypical system, but we do know of one other possible system where it could be happening,” Lisse said in response to the question posed by Universe Today. “I think this is a rare event, which might mean that life is rare if you need a Late Heavy Bombardment for life to happen.”
Lisse said the reason they studied this star was the earlier detection of the Kuiper Belt-like region around Eta Corvi. “We knew it was an exceptional system from previous infrared sky surveys and the large bright Kuiper Belt was just the tip of the iceberg,” Lisse said. “This system was shouting, ‘I’m something extraordinary, come figure out my mystery!”
Paper: Spitzer Evidence for a Late Heavy Bombardment and the Formation of Urelites in Eta Corvi at ~1 Gyr [ http://www.ast.cam.ac.uk/~wyatt/lwcm11.pdf ]
Source: Signposts of Planets conference call, JPL Press release [ http://www.jpl.nasa.gov/news/news.cfm?release=2011-322 ]
Copyright © 2011 Universe Today
http://www.universetoday.com/90068/evidence-of-a-late-heavy-bombardment-occuring-in-another-solar-system/ [with comment]
===
Strong Evidence Life Spread by Comets, Astronomers Say
Observing a nearby star system, astronomers may be witnessing an event similar to what happened in our solar system 4 billion years ago, in which comets were believed to have delivered water and organic molecules to Earth, as imagined in this artist illustration.
By Michael Schirber
Published October 19, 2011 | Inside Science News Service
A dust cloud around a nearby star appears to be the debris from a collision between a giant comet and an Earth-like planet -- possibly a re-enactment of the comet barrage that struck Earth 4 billion years ago and presumably seeded our planet with water and other necessities for life as we know it.
Using NASA's Spitzer Space telescope [ http://www.spitzer.caltech.edu/news/1319-ssc2011-08-NASA-s-Spitzer-Detects-Comet-Storm-in-Nearby-Solar-System ; http://www.spitzer.caltech.edu/ ], the astronomy team analyzed the warm dust surrounding Eta Corvi, a billion-year-old star 60 light years away from Earth in the constellation Corvus. Dust of this sort, which occurs in roughly 1 percent of stars, typically consists of the crushed-up rocks from a couple of asteroids smashing into each other.
However, Eta Corvi's dust proved to be extraordinary in that it contained signatures of water and carbon compounds, and researchers conclude that the dust is the remnants of a large comet in an upcoming paper in Astrophysical Journal [ http://iopscience.iop.org/0004-637X ].
"We observe what appears to be the result of a comet raining down on a terrestrial body in the habitable zone where life could potentially form," said lead author Carey Lisse of the John Hopkins University Applied Physics Laboratory [ http://www.jhuapl.edu/ ] in Laurel, Md.
Lisse and his colleagues have no direct proof of a planet on the receiving end of this cometary missile, but they concluded something rather big and rocky had to have shattered the comet into so many pieces. The best guess is a planet of roughly Earth size or smaller, orbiting Eta Corvi at a distance three times the Earth-sun distance. Because Eta Corvi is about 5 times brighter than the sun, this purported planet would be in the so-called habitable zone where water would remain in liquid form.
As for the comet, it most likely originated from the outskirts of the Eta Corvi system, similar to where our own solar system has its Kuiper belt, a large ring-shaped region that contains many small comet-like bodies, as well as big objects like Pluto. Evidence for a Kuiper belt-like region around Eta Corvi comes from 2005 observations of a large mass of cold debris circling the star at 150 times the Earth-sun separation.
Our Kuiper belt is fairly calm right now, but "Eta Corvi has a 'busy' Kuiper belt, like a swarm of bees, with comets flying out of the system and in towards the star," said Lisse. To explain what stirred up this "bees' nest," the authors propose a second planet of Jupiter's size or slightly smaller moving in the vicinity of Eta Corvi's Kuiper belt.
This whole story sounds like a Hollywood remake. Early in our own solar system's history, the giant planets -- Jupiter, Saturn, Uranus and Neptune -- appear to have shifted their orbital positions. This planetary shakeup disturbed our solar system's Kuiper belt, causing over 99 percent of the material to be ejected in random trajectories. Some of these comets may have contributed to the so-called late heavy bombardment, a dramatic uptick in the number of large impacts that occurred sometime around four billion years ago.
This comet onslaught may have delivered not only water to Earth, but also some of the organic building blocks of life. This possibility was recently highlighted by a meteorite, called Almahata Sitta, which landed in Sudan in 2008. Collected samples contain lots of organics, and surprisingly they have similar light-absorption signatures as the dust that Lisse and his colleagues have observed around Eta Corvi.
"We think this meteorite was a recent example of life's ingredients raining down," said Lisse.
Is it possible that Lisse's team has found a distant example of such a downpour?
That's a reasonable conclusion, according to Alessandro Morbidelli of the Observatory of Cote d'Azur in Nice, France.
"We have strong arguments for a late influx of comets from our outer solar system to the inner solar system," said Morbidelli.
Even if late heavy bombardments like this are rare, they are still bound to occur in other systems.
"Eta Corvi is probably one of those systems," said Morbidelli.
To obtain further verification, Lisse is suggesting that planet hunters train their eyes on Eta Corvi. He admits it won't be easy to detect the two planets that his group has proposed, since they are at relatively large distances from their host star. But planet detection is rapidly progressing.
"I'd bet a case of beer that in five years we'll have found planets around Eta Corvi," said Lisse.
©2011 FOX News Network, LLC
http://www.foxnews.com/scitech/2011/10/19/striking-evidence-comet-delivering-water-molecules-to-earth-like-planet/
===
(linked in):
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=67618907 and preceding and following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=59647574 and preceding and following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=66163504 and preceding and following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=67866641 and preceding (and any future following)
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=65361675 and preceding and following and http://investorshub.advfn.com/boards/read_msg.aspx?message_id=63486312 and preceding and following; http://investorshub.advfn.com/boards/read_msg.aspx?message_id=40358526 and following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=68030474 and preceding and following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=63306014 and preceding and following
This artist's conception illustrates a storm of comets around a star near our own, called Eta Corvi. Evidence for this barrage comes from NASA's Spitzer Space Telescope, whose infrared detectors picked up indications that one or more comets was recently torn to shreds after colliding with a rocky body.
Image credit: NASA/JPL-Caltech
by Nancy Atkinson on October 19, 2011
Planetary scientists have not been able to agree that a turbulent period in our solar system’s history called the Late Heavy Bombardment actually occurred. But now, using observations from the Spitzer Space Telescope, scientists have detected activity resembling a similar type of event where icy bodies from the outer solar system are possibly pummeling rocky worlds closer to the star. This is the first time such activity has been seen in another planetary system.
“Where the comets are hitting the rocky bodies is in the habitable zone around this star, so not only are life-forming materials possibly being delivered to rocky worlds, but also in the right place for life as we know it to grow,” said Carey Lisse, senior research scientist at the Johns Hopkins University Applied Physics Laboratory. “This is similar to what happened to our own solar system during the Late Heavy Bombardment.”
Lisse spoke to journalists in a conference call from the Signposts of Planets [ http://science.gsfc.nasa.gov/667/conferences/signposts.html ] meeting taking place at Goddard Space Flight Center this week.
Spitzer observations showed a band of dust around the nearby, naked-eye-visible star called Eta Corvi, located in the constellation Corvus in northern sky. Within the band of warm dust, Spitzer’s infrared detectors saw the chemical fingerprints of water ice, organics and rock, which strongly matches the contents of an obliterated giant comet, suggesting a collision took place between a planet and one or more comets. Also detected was evidence for flash-frozen rocks, nanodiamonds and amorphous silica.
This dust is located 3 AU away from Eta Corvi, which is the “habitable zone” around that star, and is close enough to the star that Earth-like worlds could exist. Lisse said although it hasn’t been confirmed, researchers think there is a Neptune-like world and at least two other planets in this system. A bright, icy Kuiper Belt-like region located 3-4 times farther out than our own Kuiper Belt was discovered around Eta Corvi in 2005.
“This is very possibly a planet-rich system,” Lisse said.
The light signature emitted by the dust around Eta Corvi also resembles meteorites found on Earth. “We see a match between dust around Eta Corvi and the Almahata Sitta meteorites, which fell to Earth in Sudan in 2008,” Llisse said. “We can argue that the material around Eta Covi is rich in carbon and water, things that help life grow on Earth.”
The Eta Corvi system is approximately one billion years old, which the research team considers about the right age for such a bombardment.
No asteroidal dust was found in the disk around Eta Corvi.
“Asteroidal dust would look like it had been heated, and chemically and physically altered, and most of the water and carbon would be gone,” Lisse said. “This dust is very rich in water and carbon and the rocky components are very primitive and un-altered.”
Most planetary formation theories can’t account for such an intense period of bombardment in our own solar system so late in its history, but the Nice Model proposed in 2005 suggests the Late Heavy Bombardment was triggered when the giant planets in our solar system— which formed in a more compact configuration – rapidly migrated away from each other (and their orbital separations all increased), and a disk of small asteroids and comets that lay outside the orbits of the planets was destabilized, causing a sudden massive delivery of asteroids and comets to the inner solar system. The barrage scarred the Moon and produced large amounts of dust.
“We can see the process of this happening at Eta Corvi and can learn more about our own solar system, since we can’t go back in time,” Lisse said. “It’s very possible that the rain of comets and Kuiper Belt Objects brought life to Earth.”
Lisse and his team are not sure if one big comet or lots of smaller comets are pummeling the inner solar system. “It is probably many bodies, but we only see the effects of the largest ones,” he said.
Could this be an indication that a Late Heavy Bombardment happens in many solar systems? “It’s not clear whether this is an atypical system, but we do know of one other possible system where it could be happening,” Lisse said in response to the question posed by Universe Today. “I think this is a rare event, which might mean that life is rare if you need a Late Heavy Bombardment for life to happen.”
Lisse said the reason they studied this star was the earlier detection of the Kuiper Belt-like region around Eta Corvi. “We knew it was an exceptional system from previous infrared sky surveys and the large bright Kuiper Belt was just the tip of the iceberg,” Lisse said. “This system was shouting, ‘I’m something extraordinary, come figure out my mystery!”
Paper: Spitzer Evidence for a Late Heavy Bombardment and the Formation of Urelites in Eta Corvi at ~1 Gyr [ http://www.ast.cam.ac.uk/~wyatt/lwcm11.pdf ]
Source: Signposts of Planets conference call, JPL Press release [ http://www.jpl.nasa.gov/news/news.cfm?release=2011-322 ]
Copyright © 2011 Universe Today
http://www.universetoday.com/90068/evidence-of-a-late-heavy-bombardment-occuring-in-another-solar-system/ [with comment]
===
Strong Evidence Life Spread by Comets, Astronomers Say
Observing a nearby star system, astronomers may be witnessing an event similar to what happened in our solar system 4 billion years ago, in which comets were believed to have delivered water and organic molecules to Earth, as imagined in this artist illustration.
By Michael Schirber
Published October 19, 2011 | Inside Science News Service
A dust cloud around a nearby star appears to be the debris from a collision between a giant comet and an Earth-like planet -- possibly a re-enactment of the comet barrage that struck Earth 4 billion years ago and presumably seeded our planet with water and other necessities for life as we know it.
Using NASA's Spitzer Space telescope [ http://www.spitzer.caltech.edu/news/1319-ssc2011-08-NASA-s-Spitzer-Detects-Comet-Storm-in-Nearby-Solar-System ; http://www.spitzer.caltech.edu/ ], the astronomy team analyzed the warm dust surrounding Eta Corvi, a billion-year-old star 60 light years away from Earth in the constellation Corvus. Dust of this sort, which occurs in roughly 1 percent of stars, typically consists of the crushed-up rocks from a couple of asteroids smashing into each other.
However, Eta Corvi's dust proved to be extraordinary in that it contained signatures of water and carbon compounds, and researchers conclude that the dust is the remnants of a large comet in an upcoming paper in Astrophysical Journal [ http://iopscience.iop.org/0004-637X ].
"We observe what appears to be the result of a comet raining down on a terrestrial body in the habitable zone where life could potentially form," said lead author Carey Lisse of the John Hopkins University Applied Physics Laboratory [ http://www.jhuapl.edu/ ] in Laurel, Md.
Lisse and his colleagues have no direct proof of a planet on the receiving end of this cometary missile, but they concluded something rather big and rocky had to have shattered the comet into so many pieces. The best guess is a planet of roughly Earth size or smaller, orbiting Eta Corvi at a distance three times the Earth-sun distance. Because Eta Corvi is about 5 times brighter than the sun, this purported planet would be in the so-called habitable zone where water would remain in liquid form.
As for the comet, it most likely originated from the outskirts of the Eta Corvi system, similar to where our own solar system has its Kuiper belt, a large ring-shaped region that contains many small comet-like bodies, as well as big objects like Pluto. Evidence for a Kuiper belt-like region around Eta Corvi comes from 2005 observations of a large mass of cold debris circling the star at 150 times the Earth-sun separation.
Our Kuiper belt is fairly calm right now, but "Eta Corvi has a 'busy' Kuiper belt, like a swarm of bees, with comets flying out of the system and in towards the star," said Lisse. To explain what stirred up this "bees' nest," the authors propose a second planet of Jupiter's size or slightly smaller moving in the vicinity of Eta Corvi's Kuiper belt.
This whole story sounds like a Hollywood remake. Early in our own solar system's history, the giant planets -- Jupiter, Saturn, Uranus and Neptune -- appear to have shifted their orbital positions. This planetary shakeup disturbed our solar system's Kuiper belt, causing over 99 percent of the material to be ejected in random trajectories. Some of these comets may have contributed to the so-called late heavy bombardment, a dramatic uptick in the number of large impacts that occurred sometime around four billion years ago.
This comet onslaught may have delivered not only water to Earth, but also some of the organic building blocks of life. This possibility was recently highlighted by a meteorite, called Almahata Sitta, which landed in Sudan in 2008. Collected samples contain lots of organics, and surprisingly they have similar light-absorption signatures as the dust that Lisse and his colleagues have observed around Eta Corvi.
"We think this meteorite was a recent example of life's ingredients raining down," said Lisse.
Is it possible that Lisse's team has found a distant example of such a downpour?
That's a reasonable conclusion, according to Alessandro Morbidelli of the Observatory of Cote d'Azur in Nice, France.
"We have strong arguments for a late influx of comets from our outer solar system to the inner solar system," said Morbidelli.
Even if late heavy bombardments like this are rare, they are still bound to occur in other systems.
"Eta Corvi is probably one of those systems," said Morbidelli.
To obtain further verification, Lisse is suggesting that planet hunters train their eyes on Eta Corvi. He admits it won't be easy to detect the two planets that his group has proposed, since they are at relatively large distances from their host star. But planet detection is rapidly progressing.
"I'd bet a case of beer that in five years we'll have found planets around Eta Corvi," said Lisse.
©2011 FOX News Network, LLC
http://www.foxnews.com/scitech/2011/10/19/striking-evidence-comet-delivering-water-molecules-to-earth-like-planet/
===
(linked in):
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=67618907 and preceding and following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=59647574 and preceding and following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=66163504 and preceding and following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=67866641 and preceding (and any future following)
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=65361675 and preceding and following and http://investorshub.advfn.com/boards/read_msg.aspx?message_id=63486312 and preceding and following; http://investorshub.advfn.com/boards/read_msg.aspx?message_id=40358526 and following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=68030474 and preceding and following
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=63306014 and preceding and following
Greensburg, KS - 5/4/07
"Eternal vigilance is the price of Liberty."
from John Philpot Curran, Speech
upon the Right of Election, 1790
F6
Join the InvestorsHub Community
Register for free to join our community of investors and share your ideas. You will also get access to streaming quotes, interactive charts, trades, portfolio, live options flow and more tools.
