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(Astronomy) Comets, Meteors and Asteroids

 
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adedios
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PostPosted: Sun Jan 08, 2006 8:32 am    Post subject: (Astronomy) Comets, Meteors and Asteroids Reply with quote






Small Space Rock Spotted Hitting the Moon
By Leonard David
Senior Space Writer
posted: 23 December 2005
03:17 pm ET

Add one more crater to the already beat-up Moon. Astronomers have recorded a tiny blip northwest of Mare Imbrium, a flash caused by a meteoroid hit within the “Sea of Showers.”

While such impacts are not uncommon, it was only in 1999 that a meteoroid hit was first recorded as it took place. This new observation of a run-in between Moon and meteoroid was recorded on Nov. 7, spotted by Robert Suggs, Space Environment team lead in the Natural Environments Branch of the Marshall Center’s Engineering Directorate in Huntsville, Alabama.

The rock is estimated to have been about 4-5 inches (12 centimeters) in diameter and to have left a crater 10 feet wide and 1.3 feet deep (3 meters by 0.4 meters).

The flash "was about as bright as a 7th magnitude star," Suggs said. That's dimmer than the faintest star a person can see with the unaided eye.

Suggs, who heads a study on lunar impacts, used commercial software tools to study video taken frame by frame, spotting the very bright flash. The burst of light diminished gradually over the course of five video frames, each 1/30th of a second in duration.

Noting the flash, Suggs called in Bill Cooke, an astronomer in Marshall’s Meteoroid Environment Office. Both scientists agreed that the bright light was an impact flash.

Other possible causes were ruled out. Two telling characteristics won out: the gradual diminishment of the flash rather than an on-off “winking” effect, and its motionlessness.

One cause that was discounted was the flicker of light from a moving satellite. That would have appeared to shift perceptibly, even in five brief frames of video, Cooke noted in a Dec. 22 press release issued by the NASA Marshall Space Flight Center.

Suggs and Cooke next consulted star charts and lunar imaging software. Doing so, they determined the meteoroid was likely a Taurid, part of an annual meteor shower active at the time of the strike, and thought to be ancient remnants from comet Encke.

Kim Newton, a spokeswoman for the NASA center, told SPACE.com that the video imagery strike was acquired from a parking lot at Marshall. The two researchers are very excited about the find, she said.

The research work is of particular interest as NASA plans to return to the Moon. The agency has a need to understand lunar impacts in order to protect future expeditionary explorers and hardware stationed on the Moon.

Earth’s atmosphere vaporizes most small meteoroids that come our way, leaving nothing behind but a brief streak of light. But there is nothing to slow incoming meteoroids before they hit the Moon.

SPACE.com's Robert Roy Britt contributed to this report.

*************************************************************

Questions to explore further this topic:

What are comets, meteors and asteroids?

http://curious.astro.cornell.edu/comets.php

What are comets?

http://www.nineplanets.org/comets.html
http://www.windows.ucar.edu/to.....omets.html
http://csep10.phys.utk.edu/ast.....omets.html
http://www.enchantedlearning.c.....omy/comet/
http://en.wikipedia.org/wiki/Comet
http://cse.ssl.berkeley.edu/Se.....place.html
http://www.pbs.org/wgbh/nova/s.....eaver.html
http://www.kidsastronomy.com/comets.htm
http://www.solarviews.com/eng/comet.htm

Parts of a comet

http://www.nasm.si.edu/researc.....atomy.html

What are comets made of?

http://cse.ssl.berkeley.edu/Se.....mmcom.html
http://cse.ssl.berkeley.edu/Se.....stics.html

Orbits and origin of comets

http://www.nasm.si.edu/researc.....rbits.html
http://cse.ssl.berkeley.edu/Se.....rbits.html

The Oort cloud

http://cse.ssl.berkeley.edu/Se.....igins.html

History of comet study and exploration

http://cse.ssl.berkeley.edu/Se.....story.html

Naming comets

http://www.nasm.si.edu/researc.....names.html

Comet images

http://www.nineplanets.org/pxmisc.html#Comets
http://www.windows.ucar.edu/to.....et_il.html
http://ares.nrl.navy.mil/sungrazer/
http://www.theastronomer.org/comets.html
http://hubblesite.org/gallery/.....on/comet_/

Did comets kill the dinosaurs?

http://cse.ssl.berkeley.edu/Se.....llers.html

Small comets

http://smallcomets.physics.uiowa.edu/

Some famous comets

http://amazing-space.stsci.edu.....ex_nf.html

The Halley's comet

http://www.solarviews.com/eng/halley.htm

What are meteors and meteoroids?

http://csep10.phys.utk.edu/ast.....teors.html
http://liftoff.msfc.nasa.gov/A.....teors.html
http://en.wikipedia.org/wiki/Meteor
http://www.astroleague.org/al/.....twhat.html
http://seds.lpl.arizona.edu/ni.....rites.html
http://csep10.phys.utk.edu/ast.....owers.html
http://www.infoplease.com/ipa/A0004503.html

What are meteorites?

http://www.crystalinks.com/meteors.html
http://en.wikipedia.org/wiki/Meteors

What are asteroids?

http://www.windows.ucar.edu/to.....roids.html
http://www.nasm.si.edu/researc.....asteroids/
http://www.nineplanets.org/asteroids.html
http://www.enchantedlearning.c.....asteroids/
http://en.wikipedia.org/wiki/Asteroid
http://www.astro.uu.se/planet/asteroid/
http://csep10.phys.utk.edu/ast.....roids.html
http://www.crystalinks.com/asteroids.html
http://starryskies.com/solar_s.....s_top.html
http://www.mira.org/fts0/plane.....xt001z.htm

List of asteroids

http://en.wikipedia.org/wiki/List_of_asteroids
http://www.enchantedlearning.c.....list.shtml
http://www.windows.ucar.edu/to.....table.html

Naming asteroids

http://www.swisr.org/col5.html
http://www.space.com/scienceas.....91021.html
http://www.nineplanets.org/names.html
http://www.open2.net/astronomy.....aming.html
http://www.mira.org/fts0/plane.....xt002z.htm

Asteroids named after Filipinos

http://home.astronomy.com.ph/?id=/200601/news1
http://www.astroleaguephils.or.....dillo.html

Asteroids with satellites

http://www.johnstonsarchive.ne.....moons.html

Images of asteroids

http://www.windows.ucar.edu/to.....id_il.html
http://nssdc.gsfc.nasa.gov/pho.....roids.html
http://nssdc.gsfc.nasa.gov/img.....nails.html

GAMES

http://cse.ssl.berkeley.edu/Se....._game.html
http://www.brainjar.com/java/games/asteroids/
http://www.nationalgeographic......asteroids/
http://deepimpact.jpl.nasa.gov.....lenge.html


Last edited by adedios on Sat Jan 27, 2007 5:04 pm; edited 2 times in total
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PostPosted: Sun Jan 08, 2006 3:23 pm    Post subject: NASA to Return Comet Samples to Earth Reply with quote

NASA to Return Comet Samples to Earth
By ALICIA CHANG, AP Science Writer
Sun Jan 8, 12:21 PM ET

Comets have long lit up the sky and the imaginations of scientists. Now these icy bodies from the beginnings of the solar system are finally ready for their close-up.

Six months after NASA scientists first peeked inside one comet from afar, they're bringing pieces of another to Earth for study under the microscope.

This weekend, the Stardust spacecraft will jettison a 100-pound capsule holding comet dust. It will nosedive through the Earth's atmosphere and — if all goes well — make a soft landing in the Utah desert.

The searing plunge is expected to generate a pinkish glow as bright as Venus that should be visible without a telescope across much of the West.

Comets — which astronomers consider to be among the solar system's leftover building blocks — have been scrutinized for centuries. But only in recent years have scientists had the technology to learn firsthand their ingredients.

Last July, the Deep Impact spacecraft released a probe that carved a crater in a comet, exposing its interior to NASA telescopes. The Stardust mission went a step further by retrieving the first samples from a comet named Wild 2, which was about 500 million miles from Earth when Stardust launched in 1999.

Comets are bodies of ice and dust that circle the sun. About 4.5 billion years ago, a cloud of gas and dust collapsed to create the sun and planets. Comets formed from what was left over, and scientists believe studying them could shed light on the solar system's birth.

"This is a true treasure," principal investigator Don Brownlee of the University of Washington said of the Stardust capsule.

But the capsule isn't home yet.

First it faces a blistering descent, piercing the atmosphere at a record-breaking 29,000 mph — the fastest re-entry of any man-made probe.

Its target is Dugway Proving Ground, a Rhode Island-sized Army base southwest of Salt Lake City where in 2004 the ill-fated Genesis probe crashed on live television after its parachute failed to open. Despite that crash, scientists recovered enough solar wind atoms for study.

To avoid another embarrassment, engineers checked Stardust's systems and believe they will work, said Ed Hirst, a mission system manager at NASA's Jet Propulsion Laboratory in Pasadena, which is managing the $212 million mission.

Stardust traveled nearly 3 billion miles halfway to Jupiter and back, looping around the sun three times. Along the way, it also captured interstellar dust — tiny particles thought to be ancient stars that exploded and died.

After five years, the 850-pound spacecraft finally reached Wild 2.

During a historic 2004 flyby, Stardust sped through the comet's coma — the fuzzy shroud of gas and dust that envelops it — to collect the microscopic samples. The particles were trapped by a catcher the size of a tennis racket, which has since been clammed up inside the capsule for the trip home.

Comet particles from Stardust would represent the second robotic retrieval of extraterrestrial material since 1976, when the unmanned Soviet Luna 24 mission brought back moon samples.

If all goes as planned, the main spacecraft will free the shuttlecock-shaped capsule about 69,000 miles from Earth late Saturday. Then the mothership will fire its thrusters and go into a perpetual orbit around the sun.

Early Sunday, the capsule will penetrate the atmosphere. As it tumbles toward the Utah desert, the temperature on its protective heat shield will spike to 365 degrees.

Traveling at supersonic speed, the capsule will release its first parachute at 100,000 feet, followed minutes later by a larger chute, which will guide it to a landing.

During Genesis, helicopters were deployed to retrieve the capsule in mid-air, but poorly installed gravity sensors on the capsule caused its parachute to fail.

For Stardust, helicopters will fly to the landing site only after the capsule has touched down. Crews will recover the capsule and bring it to a temporary clean room on the base before transferring it to the Johnson Space Center in Houston.

If the weather is too snowy or windy for helicopters to fly, NASA will send off-road vehicles to the landing site.

Scientists believe thousands of particles of comet and interstellar dust, most smaller than the width of a human hair, are locked inside the capsule.

To determine the makeup of the particles, scientists will slice the samples into even smaller chunks and probe them under powerful microscopes, said Brownlee, the mission's principal investigator.

"We are literally bringing back samples of the solar system as they were billions of years ago," he said.

If Stardust is not on target for a weekend re-entry, engineers can command the spacecraft to fire its thrusters to a backup orbit. That would postpone its return to Earth four years.

___



The StarDust website

http://stardust.jpl.nasa.gov/home/index.html
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TonyB



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Posts: 178

PostPosted: Mon Jan 09, 2006 12:27 am    Post subject: Stardust Reply with quote

Stardust carries the names of my family! Before it was launched, or about seven years ago, I was working in Ortigas and the project was soliciting names they would etch into a microchip that they would send with the probe. This was of course mainly just to drum up awareness about the project. Now after several years and a few billion kilometers of space travelled, it will finally be back home! I hope it doesn't end like the Genesis mission when the sample was damaged upon return to earth.

Wala lang. Hehehe. Very Happy

cheers!
tony.basa
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PostPosted: Sun Apr 23, 2006 2:38 pm    Post subject: One-of-a-kind meteorite unveiled Reply with quote

University of Alberta
21 April 2006

One-of-a-kind meteorite unveiled

Edmonton, Alberta, Canada -- The depths of space are much closer to home following the University of Alberta's acquisition of a meteorite that is the only one of its kind known to exist on Earth! What makes it so rare? The meteorite is 'pristine' – that is, still frozen and uncontaminated – and so provides an invaluable preserved record of material from when the solar system formed 4.57 billion years ago.
The Tagish Lake Meteorite is carbonaceous chondrite and, as such, represents primitive material from which the solar system formed. The meteorite is rich in pre-solar grains – grains from other stars that were present near our solar system when it formed. The meteorite contains primitive molecules that are the building blocks of the components necessary for life. The pristine state of the meteorite makes it especially important for scientific research purposes; it presents an unprecedented opportunity to look for extraterrestrial ices.

The University of Alberta, through the Department of Museums and Collections Services and the Department of Earth and Atmospheric Sciences, led a consortium of partners that, together, acquired the pristine samples for mutual research and heritage interests. These partners include the Department of Canadian Heritage, the Royal Ontario Museum, Natural Resources Canada, and the Canadian Space Agency.

Dr. Christopher Herd, the Curator of the University of Alberta Meteorite Collection, will lead future research on the University's approximately 650 grams of this unique extraterrestrial rock.

"What's fascinating about the Tagish Lake Meteorite is that it enables us to probe the farthest reaches of our solar system by studying material that has come to us,' noted Dr. Herd, a professor of Earth and Atmospheric Sciences at the University of Alberta. The study of the meteorite has the potential for revolutionizing our understanding of the formation of the solar system. The meteorite fell on the frozen surface of Tagish Lake, northern BC, in Canada on January 18, 2000.


###
The University of Alberta is home to Canada's second-largest meteorite collection. Most recently, Dr. Herd has established a research program in the study of meteorites from Mars; research in meteorites in the collection and others on loan to the University continues to this day. Expertise in other areas of space research reside on campus ranging from the history of space exploration to the formation of dust devils on Mars, and spanning the humanities, engineering and the sciences.
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PostPosted: Sun May 21, 2006 9:14 am    Post subject: ESA’s new camera follows disintegration of a comet Reply with quote

ESA’s new camera follows disintegration of a comet
European Space Agency

19 May 2006
http://www.esa.int/SPECIALS/Ro.....TME_0.html

The continuing disintegration of Comet 73P/Schwassmann-Wachmann 3 has allowed ESA scientists to see into the interior of the comet. Using a revolutionary camera attached to the ESA Optical Ground Station on Tenerife, they have followed the detailed twists and turns of various comet fragments.

The superconducting camera, SCAM, is an ultra fast photon counting camera, developed by ESA. It is cooled to just 300 thousandths of a degree above absolute zero. This enables its sensitive electronic detectors, known as superconducting tunnel detectors, to register almost every single photon of light that falls into it. As such, it is the perfect instrument with which to detect fast and faint changes in the fragments of the comet.
Comet 73P/Schwassmann-Wachmann 3 is a short-period comet that approaches the Sun every 5.4 years. Two apparitions ago, in 1996, the comet nucleus split into five pieces (Fragments A, B, C, D, E) of which 3 (B, C, E) were still visible at its 2001 return.

When it approached the Sun again this year, seven fragments were initially observed, indicating that the comet was breaking apart again. Indeed, as astronomers watched, further fragments broke off. Fragment B alone produced at least seven new pieces. At present, about 40 fragments are visible, most of which are likely to be very small and with irregular and short-lived activity.

SCAM was attached to the one-metre ESA Optical Ground Station telescope on 7 May 2006, when the disintegrating comet was observed . Every few microseconds, the camera reads out the number of photons that have touched it and their colour. Using the unprecedented accuracy of the camera, ESA scientists charted the evolution of the dust and gas envelopes associated with each fragment for two hours. Now they must analyse the results.

In particular they will be looking for differences in the size and shape of the fragments and also any colour differences between them that might indicate compositional differences. Other studies are made possible by SCAM’s unrivalled time resolution. Outbursts and activity from each fragment can be traced down to changes that occur on a timescale of one minute. In addition, as the dust and gas particles released from the fragments move with velocities between 0.5 and 1 kilometres per second, the observations will allow the interaction of the gas and dust flow to be studied for the two fragments closest to one another.

Comet 73P/Schwassmann-Wachmann 3 is one of the comets that was considered as a potential target for ESA’s Rosetta mission. In 1995 even before its initial splitting, it was abandoned in favour of comet 46P/Wirtanen. After the launch delay of 2003, ESA decided not to re-select 73P/Schwassmann-Wachmann 3 as the replacement Rosetta target, because of the comet’s volatile behaviour. In 2014, Rosetta will rendezvous and land on the Jupiter-family comet 67P/Churyumov-Gerasimenko.
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PostPosted: Sun May 28, 2006 12:39 pm    Post subject: Reply with quote

The Sky is Falling
by Mary K. Miller

By early October, backyard astronomers are picking up the approaching asteroid with their telescopes. The mile-wide chunk of space rock is on a collision course with the earth. On October 26, it's the brightest object in the sky, save for the moon. Traveling at nine miles per second, the asteroid enters the earth's atmosphere on October 28. Friction from the atmosphere heats the surface of the object to more than 3,000 degrees Fahrenheit. As the object sails through the atmosphere, it produces a streak of light that we call a meteor or "shooting star." About ninety miles above the earth, the extreme heat melts the meteor's hard shell and it bursts into a crackling, hissing fireball.

For the full article:
http://www.exploratorium.edu/e.....index.html
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PostPosted: Sat Sep 09, 2006 10:42 pm    Post subject: Asteroids and Meteorites Reveal Family Resemblance Reply with quote

Asteroids and Meteorites Reveal Family Resemblance
Brown University
7 September 2006

Using data collected by the Japanese space probe Hayabusa in a rendezvous with the 550-meter asteroid Itokawa, researchers have demonstrated that space weathering occurs even on small asteroids. The new data, published in Nature, confirm that the mineral composition of such asteroids is consistent with meteorites fallen on Earth.

--------------------------------------------------------------------------------

PROVIDENCE, R.I. — Asteroids and meteorites are supposed to be made of the same stuff – at least that’s what earth science teachers have been telling their students for decades. But until recently, the data didn’t quite fit the story. When researchers compared the near-infrared reflectance of asteroids (as measured from Earth) and meteorites (collected on Earth) they found enough differences to raise doubts about whether the asteroids really could be the source of Earth’s meteorites.

A detailed new comparison of the near-Earth asteroid Itokawa with existing meteorite samples confirms that the process of space-weathering can explain the difference in reflectance pattern (spectrum) between asteroids and ordinary chondrites, the most common class of meteorites.

“They [chondritic meteorites] are so abundant, there have to be many, many asteroid sources,” said Takahiro Hiroi, a senior research associate at Brown University and the paper’s lead author, “but we couldn’t find any that matched so clearly, until now. These observations really let us see space weathering at work.”

Over millions of years, the flow of high-energy ions and microscopic particles vaporizes the surface of asteroids, depositing a thin film that changes the asteroid’s optical properties. Highly weathered areas tend to appear dark and red. (The near infrared spectrum of such areas is shifted toward the red end of the spectrum.)

Hiroi visited several museums and collected dozens of samples of fresh, or newly fallen, meteorites. He rejected many samples because the oxidation caused by rain and air on the Earth’s surface changes the rock’s composition and interferes with the asteroid comparison. Together with other researchers from the Hayabusa mission, Hiroi compared the near-infrared reflectance spectra of meteorite samples with spectra observed at specific locations on the asteroid.

One sample (from a meteorite dubbed Alta’ameem, for the area in Iraq where it fell) resulted in a near-identical match after correction for the changes that result from space weathering. Those changes include a reduction in mean optical path length – usually a sign of smaller grain size – and an increase in tiny iron particles known as nanophase metallic iron or npFeo.

Hiroi was able to see the effects of space weathering by taking spectra from one light and one dark area on the asteroid’s surface. Matching the observed spectra to that of the Alta’ameem meteorite, he estimated that the highly weathered site contained about 0.069 percent nanophase metallic iron and the less-weathered site contained about 0.031 percent. Because Alta’ameem is an LL chondrite, a class that represents only 10 percent of ordinary chondrite meteorites, Hiroi suggests that there must be many asteroids in near Earth orbit with compositions similar to the more common L- and H-type meteorites.

Evidence of space weathering has been seen before on moons and larger asteroids, but such clear evidence is new for smaller asteroids, such as the 550-meter Itokawa. It had been thought that such bodies, with their smaller gravitational fields, would quickly be stripped of the weathered material. This new evidence shows that space weathered material does accumulate on small asteroids, which probably are the source of most meteorites.
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PostPosted: Sat Mar 10, 2007 8:16 am    Post subject: Reply with quote

Light Gives Asteroids Spin
9 March 2007
Max Planck Society


Researcher detect the YORP Effect on the near-Earth asteroid 2000 PH5

Astronomers have observed an asteroid change the rate at which it spins for the first time, and shown that this is due to a theoretical effect predicted but never before seen.

The international team of scientists from Europe and the United States used a range of telescopes to find that the asteroid is rotating faster by 1 millisecond every year. The acceleration in the rate of rotation is due to heating of the asteroid’s surface by the Sun. Eventually it may spin faster than any known asteroid in the solar system.

The Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect is believed to alter the way small bodies in the solar system rotate. YORP is a torque due to sunlight shining on the surfaces of asteroids and meteoroids and warming their surfaces, leading to a gentle recoil effect as the heat is emitted. By analogy, if one were to shine light on a propeller over a long enough period, it would start spinning.

For the full article:

http://www.mpg.de/english/illu.....200703092/
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PostPosted: Wed Apr 11, 2007 5:45 pm    Post subject: Asteroid named after RP scientist Kintanar Reply with quote

Asteroid named after RP scientist Kintanar

By Edwin L. Aguirre, Imelda B. Joson
Inquirer
Last updated 06:19am (Mla time) 04/12/2007


CAMBRIDGE, MASSACHUSETTS -- An asteroid circling the Sun between the orbits of Mars and Jupiter and measuring 4 to 9 kilometers in diameter has been named “Kintanar” after a 77-year-old Filipino scientist and former director of the Philippine weather service.

The International Astronomical Union (IAU) last week officially christened Minor Planet No. 6636 in honor of Dr. Roman L. Kintanar, who headed the Philippine Atmospheric, Geophysical and Astronomical Services Administration, or PAGASA, for nearly 36 years before retiring in 1994.

For the full article:

http://newsinfo.inquirer.net/i.....e_id=59956
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PostPosted: Thu Jun 21, 2007 7:22 am    Post subject: Hubble Photographs Two Huge Asteroids Reply with quote

Hubble Photographs Two Huge Asteroids
By Robert Roy Britt, Senior Science Writer

posted: 20 June 2007 10:31 am ET

The Hubble Space Telescope has imaged two of the largest known asteroids, revealing craters and other features that will soon be the targets of close-up observations by NASA's Dawn spacecraft.

Ceres is round, like a planet, and 590 miles (950 kilometers) wide. The rock, about the size of Texas, contains some 30 to 40 percent of all the mass in the asteroid belt between Mars and Jupiter.

Thought to be a planet after its discovery in 1801, Ceres was later reclassified as an asteroid. But under the new and controversial planet definition that demoted Pluto, Ceres is now considered a dwarf planet.

Vesta, the other target, is irregularly shaped and about 330 miles (530 kilometers) wide-about the size of Arizona.

For the full article:

http://www.livescience.com/spa.....vesta.html
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PostPosted: Tue Jun 26, 2007 10:47 am    Post subject: Crater Could Solve 1908 Tunguska Meteor Mystery Reply with quote

Crater Could Solve 1908 Tunguska Meteor Mystery
By Dave Mosher, Staff Writer

posted: 26 June 2007 06:27 am ET

In late June of 1908, a fireball exploded above the remote Russian forests of Tunguska, Siberia, flattening more than 800 square miles of trees. Researchers think a meteor was responsible for the devastation, but neither its fragments nor any impact craters have been discovered.

Astronomers have been left to guess whether the object was an asteroid or a comet, and figuring out what it was would allow better modeling of potential future calamities.

Italian researchers now think they've found a smoking gun: The 164-foot-deep Lake Cheko, located just 5 miles northwest of the epicenter of destruction.

For the full article:

http://www.livescience.com/spa.....rater.html
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PostPosted: Sat Jul 28, 2007 7:18 am    Post subject: What Comets Are Made Of Reply with quote

What Comets Are Made Of
Emily Sohn

July 25, 2007

Astronomers are watching a comet break into pieces, practically before their eyes. Their observations, reported by scientists at Johns Hopkins University's Applied Physics Laboratory in Laurel, Md., are giving surprising insight into the structure of these space objects.
Comets are fairly small (about 12 miles across or less) balls of ice, rock, and dust that make long, noncircular orbits around the sun. When a comet gets near the sun, the star's heat melts some of it, creating what looks like a tail. At this stage, it looks somewhat like a tadpole.

For the full article:

http://www.sciencenewsforkids....../Note2.asp
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PostPosted: Tue Aug 14, 2007 9:58 am    Post subject: Comet probes reveal evidence of origin of life, scientists c Reply with quote

Cardiff University
14 August 2007

Comet probes reveal evidence of origin of life, scientists claim

Recent probes inside comets show it is overwhelmingly likely that life began in space, according to a new paper by Cardiff University scientists.

Professor Chandra Wickramasinghe and colleagues at the University’s Centre for Astrobiology have long argued the case for panspermia - the theory that life began inside comets and then spread to habitable planets across the galaxy. A recent BBC Horizon documentary traced the development of the theory.

Now the team claims that findings from space probes sent to investigate passing comets reveal how the first organisms could have formed.

The 2005 Deep Impact mission to Comet Tempel 1 discovered a mixture of organic and clay particles inside the comet. One theory for the origins of life proposes that clay particles acted as a catalyst, converting simple organic molecules into more complex structures. The 2004 Stardust Mission to Comet Wild 2 found a range of complex hydrocarbon molecules - potential building blocks for life.

The Cardiff team suggests that radioactive elements can keep water in liquid form in comet interiors for millions of years, making them potentially ideal “incubators” for early life. They also point out that the billions of comets in our solar system and across the galaxy contain far more clay than the early Earth did. The researchers calculate the odds of life starting on Earth rather than inside a comet at one trillion trillion (10 to the power of 24) to one against.

Professor Wickramasinghe said: “The findings of the comet missions, which surprised many, strengthen the argument for panspermia. We now have a mechanism for how it could have happened. All the necessary elements - clay, organic molecules and water - are there. The longer time scale and the greater mass of comets make it overwhelmingly more likely that life began in space than on earth.”


###
The new paper, The Origin of Life in Comets, by Professor Wickramasinghe, Professor Bill Napier and Dr Janaki Wickramasinghe is to be published shortly by the International Journal of Astrobiology.
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PostPosted: Wed Aug 22, 2007 11:42 am    Post subject: Strange Asteroids Baffle Scientists Reply with quote

Strange Asteroids Baffle Scientists
By Ker Than, Staff Writer

posted: 21 August 2007 08:21 pm ET

Two space rocks in our solar system's outer asteroid belt might contain mineral evidence for a new class of asteroids or long eroded mini-worlds.

The asteroids, (7472) Kumakiri and (10537) 1991 RY16, were found to contain basalt, a grey-black mineral that forms much of the crust on Earth and the other inner planets.

Basalt has also been found in space rocks shed by Vesta, the third largest object in the asteroid belt, located between the orbits of Jupiter and Mars. The presence of basalt is evidence that an object was once large enough to sustain internal heating.

For the full article:

http://www.livescience.com/spa.....eroid.html
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PostPosted: Sat Sep 08, 2007 9:05 am    Post subject: Killer Collision: Dino demise traces to asteroid-family brea Reply with quote

Week of Sept. 8, 2007; Vol. 172, No. 10 , p. 148

Killer Collision: Dino demise traces to asteroid-family breakup
Ron Cowen

A huge chunk of rock hit Earth 65 million years ago, setting off events that wiped out the dinosaurs. That chunk, astronomers now say, was a wayward fragment from a collision between two giant asteroids in the inner part of the asteroid belt, which lies between Mars and Jupiter. The new study adds to the evidence that both Earth and moon have been bombarded by about twice the usual number of asteroid fragments during the past 200 million years.

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http://sciencenews.org/articles/20070908/fob3.asp
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PostPosted: Tue Sep 11, 2007 12:39 pm    Post subject: Asteroid Impact Would Devastate Seafloor Life, Too Reply with quote

Asteroid Impact Would Devastate Seafloor Life, Too
By Andrea Thompson, LiveScience Staff Writer

posted: 10 September 2007 03:31 pm ET

If an asteroid were to hit Earth and wipe out all life at the planet's surface, the creatures that live around deep sea hydrothermal vents would be safe from destruction, scientists have long thought. What goes on above the ocean's waves should be of little concern to creatures living 2 miles below.

But apparently it is, new research finds.

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http://www.livescience.com/ani.....tsafe.html
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PostPosted: Thu Sep 20, 2007 12:30 pm    Post subject: Dealing with threatening space rocks Reply with quote

Dealing with threatening space rocks
ESA

20 September 2007

Every now and then a space rock hits the world's media – sometimes almost literally. Threatening asteroids that zoom past the Earth, fireballs in the sky seen by hundreds of people and mysterious craters which may have been caused by impacting meteorites; all make ESA's planned mission Don Quijote look increasingly timely.

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http://www.esa.int/esaCP/SEM8SUB1S6F_index_0.html
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PostPosted: Mon Oct 15, 2007 10:56 am    Post subject: Sun Got Your Tail? Reply with quote

Sun Got Your Tail?
Jennifer Cutraro

Oct. 17, 2007

An amateur astronomer made a surprising discovery last spring. He discovered that a comet orbiting the sun appeared to have lost one of its two tails. Scientists are now studying this comet and others in greater detail.
Comets are balls of ice, rock, and dust that make long, noncircular orbits around the sun. When a comet gets near the sun, part of it melts, creating what looks like a tail.

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http://www.sciencenewsforkids....../Note3.asp
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PostPosted: Thu Nov 15, 2007 2:44 pm    Post subject: Incredible Comet Bigger than the Sun Reply with quote

Incredible Comet Bigger than the Sun
By Robert Roy Britt, Senior Science Writer

posted: 15 November 2007 10:38 am ET

A comet that has delighted backyard astronomers in recent weeks after an unexpected eruption has now grown larger than the sun.

The sun remains by far the most massive object in the solar system, with an extended influence of particles that reaches all the planets. But the comparatively tiny Comet Holmes has released so much gas and dust that its extended atmosphere, or coma, is larger than the diameter of the sun. The comparison is clear in a new image.

"It continues to expand and is now the largest single object in the solar system," according to astronomers at the University of Hawaii.

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http://www.livescience.com/spa.....-size.html
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PostPosted: Sat Nov 24, 2007 7:18 am    Post subject: Comet Flare Reply with quote

Comet Flare
Emily Sohn

Nov. 28, 2007

Comets are usually fairly predictable. But a normally small, faint comet recently did something really odd.
In less than 24 hours late last month, the ball of ice, rock, and dust, named Comet 17P/Holmes suddenly grew 400,000 times brighter than normal.

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http://www.sciencenewsforkids....../Note3.asp
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PostPosted: Wed Dec 19, 2007 3:00 pm    Post subject: Small Asteroids Pose Big New Threat Reply with quote

Small Asteroids Pose Big New Threat
By Charles Q. Choi, Special to SPACE.com

posted: 19 December 2007 06:38 am ET

The infamous Tunguska explosion, which mysteriously leveled an area of Siberian forest nearly the size of Tokyo a century ago, might have been caused by an impacting asteroid far smaller than previously thought.

The fact that a relatively small asteroid could still cause such a massive explosion suggests "we should be making more efforts at detecting the smaller ones than we have till now," said researcher Mark Boslough, a physicist at Sandia National Laboratory in Albuquerque, N.M.

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http://www.livescience.com/spa.....ittle.html
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PostPosted: Mon Dec 24, 2007 3:47 pm    Post subject: The Enduring Mysteries of Comets Reply with quote

The Enduring Mysteries of Comets
By Charles Q. Choi, Special to SPACE.com

posted: 24 December 2007 06:45 am ET

For millennia, comets were believed to be omens of doom. Instead, solving the mysteries regarding these "dirty snowballs" could help reveal the part they played in the birth of life on Earth, as well as secrets concerning the rest of the galaxy.

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http://www.livescience.com/spa.....eries.html
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PostPosted: Thu Jan 03, 2008 2:53 pm    Post subject: Must-See Meteor Shower Friday Morning Reply with quote

Must-See Meteor Shower Friday Morning
By Joe Rao, SPACE.com Skywatching Columnist

posted: 03 January 2008 08:25 am ET

The Quadrantid meteor shower is due to reach maximum in the predawn hours of Friday, Jan. 4. The Quadrantids are notoriously unpredictable, but if any year promises a fine display, this could be it.

Indeed, this may end up being the best meteor shower of 2008.

The Quadrantid (pronounced KWA-dran-tid) meteor shower provides one of the most intense annual meteor displays, with a brief, sharp maximum lasting but a few hours. The timing of peak activity favors Western Europe and eastern North America. Weather permitting, skywatchers in rural locations could see one or two shooting stars every minute during the peak.

For the full article:

http://www.livescience.com/spa.....hower.html
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