PLEASE NOTE:


*

CCNet 81/2003 - 2 October 2003
DOUBTS ABOUT NASA'S 'FIREBALL' INTERPRETATION
----------------------------------------------


A schoolboy has impressed experts at American space agency Nasa after capturing a
rare picture of a meteor burning out above his home town in south Wales. He took
two photographs of the fiery ball before it burned out and rushed home to show
his parents. Later, he emailed the picture to Nasa asking for an explanation and
was amazed to discover that the space experts were so impressed with his snap they
had published it on their website.
     --BBC News Online, 1 Oct. 2003


No reports of such an event have been received by the BAA (we get to hear
about these pretty quickly, often at the rate of once a week and more!).
Identification of this image as a fireball seems a bit doubtful to me, sorry!
     --Neil Bone, Director, BAA Meteor Section, 1 Oct. 2003

 
I don't think for a moment that there was any connection [of 2003 SW130]
with the Orissa meteorite, which, after all, fell a good week after the
asteroid's pass. Coming to within some 160,000 km of the earth, SW130 made
the sixth closest approach known for an asteroid. Actually, it was then the
fifth closest approach, for we now have 2003 SQ222, which came to a record
close distance of 90,000 km -- just a few hours after the meteorite. But
again, I strongly doubt any connection, and SW130 and SQ222, though both
probably smaller than 10 meters across, themselves have very different orbits.
     --Brian Marsden, Minor Planet Center, 1 Oct. 2003


(1) DOUBTS ABOUT NASA'S 'FIREBALL' INTERPRETATION

(2) THE SKY ISN'T FALLING, BUT PIECES SURE ARE

(3) SCHOOLBOY'S PHOTO AMAZES NASA

(4) COMET DEBRIS CITED AS FIREBALL METEOR SEEN MONDAY OVER THE SOUTH BAY

(5) SEPT. 29 FIREBALL OVER NORTHERN FRANCE

(6) GSI SCIENTIST CLAIMS METEORITES "CREATED DEEP CRATERS WHERVER THEY FELL"

(7) TWO MORE PIECES OF METEORITE FOUND IN ORISSA

(8) IS THERE AN ORISSA CONNECTION?

(9) NO CONNECTION BETWEEN ASTEROIDS AND METEORITES

(10) TIME OF 'FIREBALL' EVENT OVER SOUTH WALES

(11) PEGASUS A FALL REFERENCE POINT TO LOCATE AND VIEW COMET ENCKE


==========
(1) DOUBTS ABOUT NASA'S 'FIREBALL' INTERPRETATION

Neil Bone <bafb4@central.susx.ac.uk>

Dear Benny,

           Having been prompted to look at this by John Mason
(Assistant Director, BAA Meteor Section), I'm more thana wee bit
doubtful as to the nature of what's shown! It looks, to me, more like a
sunlit contrail, with the setting Sun off to the right from the frame
(hence that end is bright). In the image taken few minutes later, the Sun
has set further and is no longer illuminating the end of the trail. I
would be surprised if the image caught the exact end, as implied by the
lack of any continuation of the 'residual trail' beyond its earlier
extent, which further leads me to believe that this wasn't a fireball.

No reports of such an event have been received by the BAA (we get to hear
about these pretty quickly, often at the rate of once a week and more!).
Identification of this image as a fireball seems a bit douibtful to me,
sorry!

Neil Bone
Director, BAA Meteor Section

=========
(2) THE SKY ISN'T FALLING, BUT PIECES SURE ARE

Space.com, 1 Oct. 2003
http://www.space.com/scienceastronomy/chicken_little_031001.html

By Robert Roy Britt

A host of mostly coincidental recent events make Chicken Little sound ever-so-slightly more credible. In the past eight days, stuff falling from space rocked a village in India and a bathroom in Louisiana, while lighting up the skies over the San Francisco Bay area, Europe and Australia.

The most spectacular visitor from beyond was a meteorite initially said to set a village afire in India and injure 20 people this past weekend. Later reports by the BBC and elsewhere put the injuries at three.

The fireball streaking through the sky turned night into day, witnesses said. It was reported visible across a nearly 5,800-square-mile (15,000-square-kilometer) region. Two pieces about 11 pounds each (5 kilograms) were said to be recovered.

On Monday, Sept. 29, a bright fireball startled residents around San Francisco. Witnesses said it flared several times over a few seconds before disappearing below the horizon, according to a report in the San Jose Mercury News. 
 
"It's by far the brightest and longest I've ever seen,'' said Jake Burkart, an amateur astronomer who said he'd been watching shooting stars since his youth. "It was really amazing.''

Peter Jenniskens, an astronomer with the SETI Institute and NASA's Ames Research Center, told the newspaper that the event had the markings of comet debris, which is more fragile than asteroid material and therefore more likely to break apart and generate a bright flare.

The object may have landed in the ocean, Jenniskens said.

Jenniskens said the fireball might have been part of an unexpected shower of debris. Another bright meteor had been spotted five hours prior from Europe, he said.

Another bright and fiery object was seen in the night sky over Australia this past weekend, near the time of the Indian meteorite. No connection between the two has been made. An official in Australia said, however, that manmade space junk may have caused the curious event spotted from south of Queensland.

Space rocks frequently strike Earth's atmosphere. They are called meteors when streaking into the ever-denser air, where most vaporize. While in space they might be referred to as asteroids if they are large, or meteoroids if they are small. If they hit the ground, they're called meteorites.

Most of the smaller pieces light up fantastically, as shooting stars or fireballs, and never reach ground. It is not uncommon for residents of a particular region to be surprised or even shocked by a fireball, as space debris rains down on Earth daily.

Many visible shooting stars start out as bits no larger than a sand grain. It only takes a pea-sized object to generate a brilliant fireball. And even something the size of a Volkswagen can disintegrate before reaching the surface.

One that did not fully vaporize hit Roy Fausset's recently renovated bathroom Sept. 23 in New Orleans.

Fausset returned from work to find holes in his roof and two floors. A space rock was in a crawl space under the house.

"The powder room door was open and it looked like an artillery shell had hit the room," he told the Associated Press. Tests by Tulane University researchers suggest the object indeed came from space.

"I'm in shock," Fausset told the Associated Press. "Oh, that's scary. I will certainly go to church this Sunday, because the Lord was certainly sending me a message."

There are no known deaths by meteorites. But a few people have been injured throughout history, and a space rock killed a dog in Egypt in 1911. Of greater concern, astronomers say, are large asteroids that could devastate a region. None are known to be on a collision course with Earth, but astronomers are keeping a wary eye.

Copyright 2003, Space.com

===============
(3) SCHOOLBOY'S PHOTO AMAZES NASA

BBC News Online, 1 Oct. 2003
http://news.bbc.co.uk/2/hi/uk_news/wales/south_east/3155928.stm

A schoolboy has impressed experts at American space agency Nasa after capturing a rare picture of a meteor burning out above his home town in south Wales.

Jonathan Burnett, 15, was taking snaps of his friends performing skateboarding stunts near his home in Pencoed near Bridgend when a bright light in the sky caught his attention.

He took two photographs of the fiery ball before it burned out and rushed home to show his parents.

Later, he emailed the picture to Nasa asking for an explanation and was amazed to discover that the space experts were so impressed with his snap they had published it on their website.

His father Paul explained: "He has a digital camera and was out taking some pictures of his friends on the street.

"A little boy ran over and shouted 'look the sun has exploded' and Jonathan turned around and managed to take two pictures of it.

"None of us knew what it was and we thought that maybe it was a plane that had exploded.

"We were really keen to find out what it was, and so without us realising it, Jonathan had emailed the picture to experts at Nasa to ask for an explanation.

"The next thing we knew that they had used the picture on their website" he said.

Jonathan, who attends Pencoed Comprehensive School, said: "It was such a coincidence that we happened to be in the street at the time.

"I was trying out my new camera to take pictures of my friend who was doing a skateboarding trick.

Meteor facts

Meteors are caused by debris from a comet burning up in our atmosphere
When comets pass through space, they leave behind a trail of dust and ice
These comet fragments will burn up in our atmosphere if the Earth enters the trail.
From the ground, they look like jets of bright light, shooting across the sky 

"I took the first picture and then about two minutes later I took the second one before it burned out.

"One of our first thoughts was that it was the sun reflecting off the clouds.

"Everyone in school is amazed - most of my friends believe me but there are some who said they don't believe me.

"I am really interested in photography - but I don't think I will ever manage to take another picture like that," he added.

On its website Nasa described the teenager's picture as a "sofa-sized rock came hurtling into the nearby atmosphere of planet Earth and disintegrated".

"By diverting his camera, he was able to document this rare sky event and capture one of the more spectacular meteor images yet recorded. Roughly one minute later, he took another picture of the dispersing meteor trial.

Bright fireballs occur over someplace on Earth nearly every day.

"A separate bolide, likely even more dramatic, struck India only a few days ago."

Copyright 2003, BBC

===========
(4) COMET DEBRIS CITED AS FIREBALL METEOR SEEN MONDAY OVER THE SOUTH BAY

San Jose Mercury News, 1 Oct. 2003
 
A bright fireball that streaked over the South Bay on Monday evening may have been debris from a comet, according to an astronomer.

The meteor -- commonly called a shooting star -- traveled east to west at 7:57 p.m. Observers said it flared several times from three to 10 seconds before disappearing over the horizon.

"It's by far the brightest and longest I've ever seen," said Jake Burkart, 29, of San Jose, an amateur astronomer who has been watching shooting stars since he was a child. "It was really amazing."

Meteors are streaks of light left by bits of space dust as they enter the upper atmosphere and evaporate. The dust may come from a rocky asteroid or from a comet, which is a loose conglomeration of rock and ice.

Peter Jenniskens, an astronomer with the SETI Institute at NASA/Ames Research Center, said the meteor's appearance is typical of comet dust, which is more fragile than the dust from an asteroid and more likely to break up and flare.

Five hours earlier, he said, another bright meteor was seen over Europe, where it reportedly glowed green or blue, broke into fragments and left a persistent, shining trail.

"So maybe we have a bit of a shower of bright fireballs going on at the moment, which is interesting," Jenniskens said.

Although showers of meteors periodically light up the skies as the Earth passes through a thick patch of cometary dust, no such shower was expected on Monday night, he said. The next one, called the Draconids shower, is supposed to arrive Oct. 9.

Jenniskens said whatever caused Monday's fireball appears to have landed in the ocean
 
Copyright 2003, San Jose Mercury News

============
(5) SEPT. 29 FIREBALL OVER NORTHERN FRANCE

Marco Langbroek <marco.langbroek@wanadoo.nl>
posted on IMO-news

Hello all,

From the observations with indications of sky directions I have so far
(sightings from Leuven in Belgium, Saarland in Germany, Almelo in the
Netherlands and Loon op Zand in the Netherlands) for the 29 september 21:11
UTC fireball, it appears that it must have been over Northern France in the
vicinity of Verdun. The reported directions of the endpoint are reasonably
in agreement with regard to this position. There is one additional possible
sighting from Tongeren in Belgium, which however nowhere matches with the
other observations. Perhaps this was another meteor.

With regard to the trajectory direction and entry angle, things remain a bit
too uncertain although it would appear that the entry angle was steep as
both observers east of the meteor, north of it and northeast of it report
steep angles with the horizon.

Two observers report fragmentation near the end, green or blue colors are
mentioned, and at least one observer reports a persistent train of long
duration.

- Marco

----------
Marco Langbroek

marco.langbroek@wanadoo.nl
meteorites@dmsweb.org
http://home.wanadoo.nl/marco.langbroek

===========
(6) GSI SCIENTIST CLAIMS METEORITES "CREATED DEEP CRATERS WHERVER THEY FELL"

Press Trust of India, 1 Oct. 2003
http://www.rediff.com/news/2003/oct/01oris.htm

Orissa villagers, still dazed at the rare sight of a flaming meteor screaming across the night sky of September 27, stumbled upon more debris even as the Geological Survey of India said the rock-like materials found in Kendrapara district were extra-terrestrial objects.

Unusual looking objects were recovered from two villages of the district, Sanamarichapalli under Rajnagar police station and Subarnapur under Pattamundai police station, on Tuesday morning, official sources said.

The objects are solid and rock-hard, have a black exterior while broken pieces are grey in colour. They were found in unmanned areas and the two largest weighed over three kg each.

Villagers of Paschima Suniti and Benakanda villages had found such objects in paddy fields within hours of sighting the fireball shooting across the sky dazzling at least 11 Orissa districts.

Dr K C Sahu, senior GSI scientist who had arrived in Kendrapara on Monday, said the rocks had created deep craters wherever they fell.

The villagers are depositing the debris with the police at Rajnagar and Pattamundai. The latter have been instructed by the district authorities to hand the debris over to the emergency wing of the collectorate.

According to Dr Sahu, the objects would be taken to the GSI's well-equipped laboratory in Bhubaneswar on Wednesday and later to the organisation's headquarters in Kolkata for scientific study.

Sahu revealed that remains of meteorites found elsewhere in the nation were kept in Kolkata's National Museum.
 
Copyright 2003 PTI. All rights reserved.

===========
(7) TWO MORE PIECES OF METEORITE FOUND IN ORISSA

The Times of India, 2 Oct. 2003
http://timesofindia.indiatimes.com/cms.dll/html/uncomp/articleshow?msid=212496

KENDRAPADA: Two more pieces of meteorite were found on Monday in Kendrapada district by the villagers of Sanamarichi of Rajanagar block and Subarnapur village of Pattamun-dai block.

On Sunday, the seaside villagers of Pashimasuniti and Barakanda under Mahakalapada block, too, had re-trieved two pieces of meteorite.

All the four pieces of rare objects from space are now kept in the office of the Kendrapada district collector.

Scientists of the Geological Survey of India visited all the four places and collected soil samples from the spots. The meteorite may have fallen from Mars and the GSI scientists will examine those in Kolkata, stated senior geologist Monoranjan Mohanty. He added that for the first time a meteor-ite had fallen in Orissa.

Though around 90 per cent of the meteorite get lost in the sea or in re-mote places, villagers were alert enough to retrieve the four pieces of the rare object in the coastal district of Kendrapada this time.

The GSI scientists have also collected soil samples from places where the pieces of meteorite had fallen.

Many villagers have even stolen some small pieces of the meteorite for which the district administration has directed the police to recover those pieces from them.

Moreover, with people from the district and other places scouting around for some pieces of the meteorite, the police are not allowing these people to visit these areas, said inspectorin-charge of Pattamundai police station Bauribandhu Behera.

State museum official Umakanta Mohanty has also visited the spots. He told TNN that the museum must pre-serve the rare objects.

He further stated that as the GSI will take away the meteorite from the state, the people of Orissa will be deprived. Mohanty though claimed that GSI was the only legal custodian of the meteorite and the museum officials had no right on these pieces.

He emphasised that science will certainly prevail over people's sentiments.

Dictrict collector Hemant Sharma stated that it will give away the four pieces of meteorite to a government agency once the state government gives the go-ahead.

(Ashis Senapati)
 
Copyright 2003, The Times of India


=========== LETTERS ============

(8) IS THERE AN ORISSA CONNECTION?

Andy Smith <astrosafe22000@yahoo.com>

Hello Benny and CCNet,

In our search for possibly related events to the
Orissa (India) impact on 27 September, we noticed the
discovery of NEO 2003SW130 by SPACEWATCH (SW). Arianna
Gleason first noticed it on the 20th  and she and Tom
Gehrels then followed it for several nights and
obtained additional measurements from the Klet and the
VLT. Brian MArsden and the MPC team were working with
them, all the way. What terrific teamwork and
cooperation. Just the spirit we are all looking for.
Bravo.

This happens to be the smallest NEO ever detected by
the SW and designated by the MPC (see item 6, CCNet 26
September)....and it is an Aten (mag. 29.1)! The
orbit and details are now on file.

The closest approach of this little jewel was on the
19th of September (about 162,000 km away and less than
half the distance to the moon). It was tricky, but
they found it...using the 1.8 meter that Tom and his
team worked so hard to build. We salute the entire SW
team for this accomplishment and for their long and
dedicated support of planetary protection. They
pioneered CCD asteroid hunting...and they have paved
the way for the rapid growth of our critical
data-base....and LINEAR and NEAT and LONEOS and others
have joined, in a great way,  in this important
mission.

Orissa Connection

As they were observing this new object, for 3 nights,
they noticed that the trail had decreased to about 1/4
its original size. We noticed 130, at the head of the
MPC Aten list, as we were searching for possible
companions of or parents to Orissa (and possibly
others).

We again ask the "big boys and girls", in the NEO
hunting community (and others with large telescopes)
to keep an eye out for other "little ones", over the
next week or two. Also, it would be nice to know if
the dots can possibly be connected...between 130 and
Orissa.

Cheers,

Andy Smith/IPPA
astrosafe22000@yahoo.com

============
(9) NO CONNECTION BETWEEN ASTEROIDS AND METEORITES

Brian Marsden <brian@cfaps5.cfa.harvard.edu>

Dear Benny,

      While I appreciate Andy Smith's kind comments about the cooperation that
allowed a rather good orbit determination to be made for 2003 SW130, I don't
think for a moment that there was any connection with the Orissa meteorite,
which, after all, fell a good week after the asteroid's pass.  Coming to
within some 160,000 km of the earth, SW130 made the sixth closest approach
known for an asteroid.  Actually, it was then the fifth closest approach,
for we now have 2003 SQ222, which came to a record close distance of 90,000 km
--just a few hours after the meteorite.  But again, I strongly doubt any
connection, and SW130 and SQ222, though both probably smaller than 10 meters
across, themselves have very different orbits.  And not entirely by chance,
SQ222 also represented an excellent case of cooperation, for Peter Birtwhistle
succeeded in securing images of it from his observatory in Great Shefford,
Berkshire, between the sets made by the LONEOS survey in Arizona on Sept. 28
and 29.

     While the information about the trajectories of the recent meteorites and
fireballs is more spotty than that about the two asteroids, there is again no
reason to relate them.  On Monday, the same day I read in CCNet about the
Orissa meteorite, I had a visit from a high-school student who had done some
research on 1999 AN10 a couple of years ago and was here to participate in the
early-applicant process for Harvard University, which he would like to attend
a year from now.  He was not himself aware of the Orissa meteorite at the time,
but in the course of our discussion he happened to mention that his mother
came from Cuttack, one of the towns in Orissa from which I had read of
sightings of the meteorite.  Cuttack, Orissa, is not a geographical location
that generally comes to my mind even once a day.

Regards
Brian

=======
(10) TIME OF 'FIREBALL' EVENT OVER SOUTH WALES

Jon Burnett< Burnskatejon@aol.com>

Hi

This is Jon Burnett. I took the photo last wednesday, the 24th 03, around 6 to half past
in the evening.

Jon Burnett

============
(11) PEGASUS A FALL REFERENCE POINT TO LOCATE AND VIEW COMET ENCKE

John Michael <john.michael@morien-institute.org>

Dear Benny,

It seems that later this month on October 25th the Earth will be in just the right place, and with a much desired moonless night, for skywatchers with a good pair of binoculars or a small telescope to see Comet Encke as it passes by the M31 Andromeda Galaxy. More details from:

The Oregonian - October 1st 2003
http://www.oregonlive.com/science/oregonian/index.ssf?/base/science/1065009370244190.xml
"Pegasus a fall reference point to locate, view Comet Encke"

When it comes to finding interesting objects in the sky, one thing often leads to another.
This month, the most prominent constellation of the fall will lead skywatchers to views beyond our Milky Way galaxy and later in the month right to a passing comet.

Look to the southeast as darkness falls and you will see four bright stars forming a large square. This is the Square of Pegasus, the easy-to-spot feature or "asterism" of the constellation Pegasus. When you look in this direction, you are looking perpendicular to the spiral arms of the Milky Way galaxy that covers the sky in summer. The Square of Pegasus serves as a window into deep space.

From a city location, this window seems empty, framed only by the bright four, relatively nearby stars. A clear night from a dark location will reveal more -- dimmer and more distant stars inside the window. Grab your binoculars and you will see many more stars that lie even deeper in space. A small telescope will reveal stars at the very edge of our galaxy, and if you know where to look, you can spot distant galaxies that are island universes of stars millions of light-years away.
Observing distant galaxies is challenging for telescope owners under very dark skies, but one galaxy can be found easily without optical aid from a dark location and with binoculars from anywhere. The Andromeda galaxy, also known as M-31, is a giant companion to the Milky Way galaxy. At more than 2 million light-years distance, it is the farthest object visible with the unaided eye. It lies very near Pegasus.

First find the not-very-conspicuous stars of Andromeda, connected to the Great Square. Look for a long lazy "V" of stars extending to the left from the northeast corner of the square. North of the V is M-31, which appears as an elongated hazy patch of light. It covers more sky than the full moon and won't fit in the field of view of most telescopes. Binoculars offer the best view. Although comprised of billions of suns, the galaxy is so distant no telescope on Earth can reveal individual stars without taking a long exposure photograph.

If you can find M-31, you can find Comet Encke just as it first comes into view. Comet Encke was the second comet, after Halley, to have its orbit around the sun defined. Although Encke appears every 3.3 years, the Earth has to be in just the right place, as it is this year, for us to have a good view. A moonless night is a must for viewing this comet, and just such a night occurs Oct. 25 when Encke moves past what should now be the familiar Andromeda galaxy.
The comet becomes bright enough to be seen in good binoculars or a small telescope at this time. Look two finger-widths above the galaxy. It will appear as a hazy patch with a bright center. Once you have found Comet Encke, keep track of it as it crosses the sky and grows to maximum, naked-eye brightness toward the end of November.

Planets shine Mars continues to attract attention during October. Although slowly fading, the Red Planet still appears larger in telescopes than it will be until 2018, and it will remain in the night sky not only throughout fall, but for months to come.

Jupiter shines brilliantly above the eastern horizon before sunrise, and fleet Mercury joins it at the beginning of the month. The tiny planet disappears in morning twilight by the end of the first week of the month.

Regards to all on the CCNet,
John Michael


-----------
CCNet is a scholarly electronic network. To subscribe/unsubscribe,
please contact the moderator Benny Peiser <b.j.peiser@livjm.ac.uk>.
Information circulated on this network is for scholarly and educational
use only. The attached information may not be copied or reproduced for
any other purposes without prior permission of the copyright holders.
DISCLAIMER: The opinions, beliefs and viewpoints expressed in the
articles and texts and in other CCNet contributions do not necessarily
reflect the opinions, beliefs and viewpoints of the moderator of this
network.


*

CCNet 82/2003 - 2 October 2003
------------------------------

Small meteorites are not hot when they hit the ground
(they are only heated briefly as they pass through the
atmosphere, and generally have some minutes to cool when
they reach terminal velocity after the huge deceleration
phase of their fall). The Orissa event caused fires, so
I am very curious about whether there are indeed some cases
of small meteorites hitting while still hot, or if this
is perhaps not a true meteorite.
    --Phil Plait, 2 October 2003


(1) CLOSEST ASTEROID YET FLIES PAST EARTH

(2) ORISSA EVENT RAISES QUESTIONS

(3) DID COMETS MAKE LIFE ON EARTH POSSIBLE?


==========
(1) CLOSEST ASTEROID YET FLIES PAST EARTH

New Scientist, 2 October 2003
http://www.newscientist.com/news/news.jsp?id=ns99994228
 
An asteroid about the size of a small house passed just 88,000
kilometres from the Earth by on Saturday 27 September - the
closest approach of a natural object ever recorded. Geostationary
communication satellites circle the Earth 42,000km from the planet's
centre.

The asteroid, designated 2003 SQ222, came from inside the Earth's
orbit and so was only spotted after it had whizzed by. The first
sighting was on Sunday 28 by the Lowell Observatory Near-Earth
Object Search program in Arizona, US.

Amateur astronomer Peter Birtwhistle of Great Shefford, Berkshire,
UK, then photographed it on Monday 29. This provided data that
helped Brian Marsden, of the Harvard-Smithsonian Center for
Astrophysics, to calculate its orbit.

The asteroid's 1.85-year orbit is quite eccentric, indicating it
cannot be a man-made object, Marsden says. He estimates the
asteroid measured less than 10 metres. This is too small to have
posed a danger to Earth, although it would have made a spectacular
fireball had it entered the atmosphere.

House fires
   
The passage came at about 2300 GMT, only 10 hours after a bright
fireball streaked over the Orissa region of India. Indian villagers
have found pieces of the meteorite, which reportedly cause two house
fires. However, this event was not connected to the fly past of 2003
SQ222, says Marsden.

The previous record for closest approach of an asteroid - 108,000km
measured from the centre of the Earth - was set in 1994 by another
10m object named 1994 XM1.

But the third-closest approach - at 120,000km - was object 2002 MN,
which was about 80m in diameter. If on target, that could have
exploded in the Earth's lower atmosphere and devastated a couple
of thousand square kilometres on the ground.

Another small asteroid, 2003 SW130, missed the Earth by 160,000km on
19 September, making it a busy month for asteroid watchers.
 
Jeff Hecht

Copyright 2003, New Scientist
 
=============
(2) ORISSA EVENT RAISES QUESTIONS

Phil Plait <badastro@badastronomy.com>

Hi Benny!

I am following the news from Orissa with keen interest, as I imagine
many of your readers are. I'm suspicious though; as I've written
before, small meteorites are not hot when they hit the ground (they
are only heated briefly as they pass through the atmosphere, and
generally have some minutes to cool when they reach terminal velocity
after the huge deceleration phase of their fall). The Orissa event
caused fires, so I am very curious about whether there are indeed
some cases of small meteorites hitting while still hot, or if this
is perhaps not a true meteorite. For example, space debris (spent rocket
engines, for example) can still be hot upon impact. We have seen many
claims of meteorite impacts that have turned out to be other, more
mundane objects such as fireworks. While the Orissa object was
clearly not fireworks, I am not yet convinced we know it was a meteorite.

Please keep us up-to-date with the latest findings! I will be very
interested in reading about what the experts determine about this
event.

-Phil

*    *    *    *    *    The Bad Astronomer    *    *    *    *

Phil Plait                    badastro@badastronomy.com
The Bad Astronomy Web Page: http://www.badastronomy.com

============
(3) DID COMETS MAKE LIFE ON EARTH POSSIBLE?

National Geographic News, 2 October 2003
http://news.nationalgeographic.com/news/2003/10/1002_031002_cometstudy.html

Stefan Lovgren

An ambitious new NASA research project aims to answer perhaps the most vexing and profound of scientific mysteries: How did life on Earth begin?
The multimillion-dollar undertaking, led by the NASA Goddard Space Flight Center in Greenbelt, Maryland, brings together an interdisciplinary team of scientists from around the world to study how organic molecules are created in interstellar clouds and delivered to planets as they form.

The research will focus on the role of comets. Many scientists believe there is increasing evidence that comets supplied at least part of the raw material for the origin of life on Earth. The theory is changing the way scientists think about life in the universe and raises the possibility of alien worlds.

"Our mission is to gain a greater understanding of the origin and evolution of organic material on Earth," said Michael Mumma, a comet expert and director of the Goddard Center for Astrobiology, NASA Astrobiology Institute, who is leading the research. "The key question is: Were water and organic molecules delivered to Earth by cometary impact and does [that process] extend to planets elsewhere?"

Dirty Snowballs

Astronomers believe that stars, planets, and comets form in a massive chain reaction that begins when a cloud of interstellar material collapses under its own gravity. Some of the material forms the star-like our sun-and some of it gets spread out in a disk around the nascent star.

Some material in this disk later aggregates and forms planets. Close to the sun, where it's warm, leftover debris (rocky material) turns into asteroids. In the outer regions, where it's cold, icy chunks of rock and dust turn into comets.

It is generally believed that organic molecules, which contain carbon atoms and are present in all life forms known to science, are trapped in large amounts in both interstellar clouds and comets.

"We have extremely definite evidence from our radio observations that there's quite an array of organic molecules in interstellar space," said Bill Irvine, a professor of astronomy at the University of Massachusetts in Amherst, who is measuring radio waves from celestial objects as part of the research effort.

There's other evidence that comets contain organic material. When European spacecraft analyzed dust particles from the Halley comet in 1986, it turned out to be some of the most organic-rich material measured in the solar system. Meteorites that have hit Earth contain a whole suite of molecules, including amino acids, which play an important role in terrestrial biology.

"If such material exists in meteorites, which come from a class of asteroids, there's every reason to think it must also exist in comets," Irvine said.

Panspermia Goes Primordial

Most scientists have long believed that life on Earth began as a "primordial soup" in a lake or pond some four billion years ago. According to this theory, chemicals from the atmosphere combined with some form of energy necessary to make amino acids-the building blocks of proteins-to create the first primitive organisms, kicking off the evolution of Earth's species.

But the primordial soup theory is being increasingly disputed. Many geophysicists now say the Earth did not have enough gases, like ammonia and methane, from which organic material like amino acids could be produced.

Instead, a growing cadre of scientists believes the organic material needed to create life may not have been produced on Earth, but was instead brought here by comets. The newly formed Earth was likely subjected to a fierce bombardment of comets four billion years ago. These comets may have brought with them the organic compounds that later evolved into living matter.

According to the most radical theory, known as "panspermia," life in a ready-made form is ubiquitous in the galaxy and is brought by comets to new planets. Few scientists subscribe to this hypothesis, however.

Perhaps the main question is whether organic molecules can survive space travel or if they break up and contribute the atoms that are necessary to ultimately make biological material and water?

"Our museums contain examples of primitive meteorites that likely are very similar to the material delivered by comets," said Mumma. "The key point is that small bodies deliver their organics intact to Earth's surface. This must have been a common event on the early Earth."

Many scientists are now leaning toward a combination of the comet impact theory and the primordial soup thesis. Some chemical building blocks may have come from comets, but the assembly into life took place on Earth.

"The comet impact theory fits in with the primordial soup theory," Mumma said. "They can be complimentary."

Drilling Into Comets

Scientists will measure the molecular make-up of comets to better understand what chemical reactions formed them. This may provide clues to the evolution of carbon-based chemistry on Earth in its early history.

The new research will combine laboratory experiments, observations with telescopes and spacecraft, and missions to sample comet and asteroid material. A European mission not associated with NASA is even going to land on a comet and drill into it as the comet journeys toward the sun.

An important part of the project will focus on water, which is seen as an essential ingredient of life. Scientists want to know if the Earth's water was incorporated into the Earth as the planet formed or if the water arrived on Earth as a result of cometary impacts after the Earth was already formed.

"Earth's new oceans were filthy, and should have been full of organic molecules and dust particles carried to our planet by comets and primitive meteorites," said Mumma. "We want to learn how significant their contribution was to the genesis of life on Earth."

The comet research could have a tremendous impact on the quest to find life on other planets. After all, comets have slammed into many other planets. If they supplied the raw material to form life on Earth, what is to say the same thing hasn't happened on other planets?

One thing is for sure, however. Finding out exactly how life on Earth began, and if it extends elsewhere, will take some time. The first stage of the NASA project will last five years, but Mumma thinks it could take as much as 25 years before scientists have a definite answer about the origin of life on Earth.

Copyright 2003, National Geographic News

-----------
CCNet is a scholarly electronic network. To subscribe/unsubscribe,
please contact the moderator Benny Peiser <b.j.peiser@livjm.ac.uk>.
Information circulated on this network is for scholarly and educational
use only. The attached information may not be copied or reproduced for
any other purposes without prior permission of the copyright holders.
DISCLAIMER: The opinions, beliefs and viewpoints expressed in the
articles and texts and in other CCNet contributions do not necessarily
reflect the opinions, beliefs and viewpoints of the moderator of this
network.



CCCMENU CCC for 2003

The content and opinions expressed on this Web page do not necessarily reflect the views of nor are they endorsed by the University of

The content and opinions expressed on this Web page do not necessarily reflect the views of nor are they endorsed by the University of Georgia or the University System of Georgia.