PLEASE NOTE:


*

CCNet 44/2003 - 1 May 2003
----------------------------------

"A major catastrophe 251 million years ago left life teetering on the brink of oblivion. Now for the first time we have a clear picture of what   caused it, says leading palaeontologist Michael Benton"
           --New Scientist, 26 April 2003 (p.38)

"Sometimes in science, if you want answers, you just have to bust things up. That's what Kazushige Tomeoka and colleagues did in order to learn why most of the space dust that falls to Earth is wet, while larger space rocks found on the planet are usually dry as a bone."
          --Robert Roy Britt, Space.com, 30 April 2003


(1) WIPEOUT: NEXT ROUND IN THE PERMO-TRIASSIC MASS EXTINCTION DEBATE
    New Scientist, 26 April 2003 (p.38)

(2) 'SHOCKING' EXPERIMENT REVEALS HOW ASTEROIDS EXPLODE
    Space.com, 30 April 2003

(3) METEORITES UNDER FIRE
    Nature, 1 May 2003

(4) ASTEROIDAL LAVA FLOWS
    Planetary Science Research, 28 April 2003

(5) BEPPOSAX SATELLITE FALLS HARMLESSLY INTO OCEAN
    Space.com, 30 April 2003

(6) H. JAY MELOSH ELECTED TO NATIONAL ACADEMY OF SCIENCES
    Ron Baalke <baalke@zagami.jpl.nasa.gov>

(7) BRAVO SLOAN AND AIAA
    Andy Smith <astrosafe22000@yahoo.com>


=============
(1) WIPEOUT: NEXT ROUND IN THE PERMO-TRIASSIC MASS EXTINCTION DEBATE

From New Scientist, 26 April 2003 (p.38)

A major catastrophe 251 million years ago left life teetering on the brink of oblivion. Now for the first time we have a clear picture of what caused it, says leading palaeontologist Michael Benton

251 MILLION years ago, at the end of the Permian period, life on Earth was almost completely wiped out by an environmental catastrophe of a magnitude never seen before or since. All over the world complex ecosystems were destroyed. In the sea, coral reefs, fishes, shellfish, trilobites, plankton, and many other groups disappeared. On land, the sabre-toothed gorgonopsian reptiles and their rhinoceros-sized prey, the dinocephalians and pareiasaurs, were wiped out forever. Only 5 per cent of species survived the catastrophe, and for the next 500,000 years life itself teetered on the brink of oblivion. What terrible event could have wrought such havoc?

Two theories have been proposed -the impact of a huge meteorite or comet over 10 kilometres in diameter, or a massive and prolonged volcanic eruption. Up to now the evidence has been equivocal. But the data has been accumulating over the past 10 years, and the picture is now clear enough to say with some certainty what happened.

An impact might seem a tempting model. A massive catastrophe demands an extraordinary explanation -something unexpected, something from outer space. And we know that impacts can cause mass extinctions. It seems that the dinosaurs and many other groups of animals and plants were wiped out 65 million years ago by the impact of a huge meteorite in modern day Mexico. The crater has been found, there is good evidence for the shock wave, and for the fa1lout rocks and dust all round the world. In February 2001, a team of scientists claimed they had found clear evidence that the mass extinction at the end of the Permian was also caused by a meteorite impact. Luanne Becker of the University of Washington in Seattle and her colleagues from NASA and other institutions announced in a paper in Science (Vol291, p 1530 ) that they had found extraterrestrial helium and argon in rocks from the Permo-Triassic boundary in China and Japan.

The gases were trapped inside the fullerenes or buckyballs that are often associated with impact debris. When Becker and her team looked closely at the helium and argon they found isotope ratios like nothing else on Earth, but similar to those found in meteorites. On this basis they argued that the fullerenes -and their entrapped gases -must have come from an impact.

The claim was splashed all over the press. On 23 February 2001, The New York Times reported "Meteor crash led to extinctions in era before dinosaurs". The Times said, "Asteroid collision left the world almost lifeless".

But later in 2001, several learned journals published critiques in which other geochemists tried and failed to replicate Becker's results. Other samples from the same boundary bed in China apparently contained no buckyballs, argon or helium, and a Japanese geologist, Yukio Isozaki of the University of Tokyo, pointed out that the Japanese sample came from a rock formation that didn't even include the Permian-Triassic boundary.

But Becker and her team still stand by their results. They repeated their analyses from the Chinese samples, and confirmed the helium result. They also have support from an independent source. ln September 2001, Kunio Kaiho ofTohoku University in Japan reported that sediment grains from Permo-Triassic boundary sections in China show evidence of compression by impact, as well as geochemical shifts indicative of a huge impact -though his data is far from conclusive.

All in al1, the evidence for an impact at the Permo-Triassic boundary is limited when compared with the mass of evidence for an asteroid hit at the end of the Cretaceous: the iridium anomaly (a worldwide spike in the abundance of iridium, an element derived from meteorite impacts); shocked quartz (grains showing evidence of high-pressure modification); glassy spherules (melt particles derived from sedimentary rocks); and above all an enormous crater of the correct age. The discovery of a Permian equivalent of any of these could confirm the impact theory at any moment. But for now, most geologists do not accept the impact model for the crisis at the end of the Permian.

Instead, their attention has focused on Earth-bound processes. The idea is that massive volcanic eruptions, sustained over half-a-million years or more, caused catastrophic environmental deterioration -poison gas, global warming, stripping of soils and plants from the landscape,
eruption of gases from their frozen locations deep in the oceans, and mass deoxygenation. The evidence for this version of events is compelling compared with the impact hypothesis.

First and foremost, the end of the Permian was indeed characterised by huge volcanic eruptions. The remains of these are preserved in the Siberian Traps, a vast accumulation of basalt lavas some 3 million cubic kilometres in volume and covering 3.9 million square kilometres of what is now eastern Russia.

Precise dating of the Siberian Traps shows that they span the boundary between the Permian and the Triassic, with the eruptions beginning perhaps 500,000 years before.

The Siberian Traps were not formed by explosive eruptions from classic cone-shaped volcanoes. More commonly, basalt is erupted through fissures, long cracks in the ground, as happens on Iceland today. Such eruptions last for a long time, and the lava bubbles up in huge volumes, spreading sideways from the fissure. They are accompanied by prodigious outpourings of gases, mostly carbon dioxide.

The effect of these gases was devastating. The full story of the havoc they wrought is written in the sedimentary rocks that span the Permo-Triassic boundary. Until the 1990s, geologists had to rely on incomplete or hard-to-date sections in northern Italy, Pakistan and Afghanistan. Reputedly excellent sections in southern China were not available to overseas geologists, mainly for political reasons. Nothing daunted, British geologists Tony Hallam of the University of Birmingham and Paul Wignall of the University of Leeds obtained a modest travel grant from the Royal Society, and went to China in 1991. What they found amazed them : the rock record was complete, and it told the story of the crisis millimetre-by-millimetre as they worked their way through the rocks from bottom to top.

Hallam and Wignall focused on sections around the Meishan township. Working up through the succession, the last rocks deposited in the Permian were limestones containing diverse and abundant fossils, such as foraminiferans (microscopic shelled protozoans), brachiopods (lamp shells), and conodonts (jaw elements from primitive fish-likevertebrates). Rarer fossils include cephalopods (coiled molluscs that are distant relatives of the modern squid and octopus), sea urchins, starfish and small crustaceans called ostracods, all typical of warm, shallow seas. Near the top, there is extensive burrowing in the limestones, indicating conditions of full oxygenation. Clearly, life at this time was diverse and abundant.

Then, suddenly, everything changes. The thick, burrowed limestones disappear, and with them the abundant fossils. The limestone is capped by a mineral-rich layer containing lots of pyrite -a classic marker of very low atmospheric oxygen. On top of this are three layers of limestone, mudstone and clay, encompassing about half a million years. These layers, numbered as beds 25, 26 and 27 in the Chinese system, tell how the crisis unfolded, so let's look at them in more detail. The oldest layer, bed 25, is a thin band of pale-coloured clay 5 centimetres thick in which fossils are very rare, just a few foraminiferans and conodonts. Under the microscope, this clay contains small iron-rich pellets and decayed pieces of quartz that indicate it was formed from an acidic ''tuff'', an amalgam of volcanic fragments and ash from an explosive volcanic eruption -presumably the Siberian Traps. The next bed up, number 26, consists of 7 centimetres of dark, organic-rich limey mudstone in which fossils are slightly more abundant-there are brachiopods, clams and cephalopods. Based on the relatively diverse fossils, and on geochemical evidence, oxygen levels during deposition of bed 26 were low but not anoxic.

Together, beds 25 and 26 form a distinctive dark-on-light marker band that has been detected elsewhere in China, which is useful for geologists who wish to make correlations from location to location. This "ash band" has been detected so far in 12 provinces throughout China, covering at least a million square kilometres. Whatever created it was extremely far-reaching.

Bed 27 indicates some degree of environmental recovery. The 17-centimetre-thick layer of limestone is full of burrows, so bottom conditions were not especially low in oxygen. The lower part of the bed contains occasional Permian brachiopod fossils near the base. Near the top, the conodont Hindeodus parvus appears for the first time: this is the globally accepted marker for the beginning of the Triassic period. (Geological boundaries are marked by the appearance of fossils, not their disappearance. The major event happened at the base.of bed 25, but no significant new species appeared until the middle of bed 27.) What does it all mean? One of the stories the Meishan section tells is of a dramatic extinction event. In the late l990s, Jin Yugan and his colleagues from the Nanjing Institute of Geology and Palaeontology, and Doug Erwin from the National Museum of Natural History in Washington DC, undertook a huge sampling programme. They found that at the base of bed 25, 116 marine species suddenly disappeared, representing 94 per cent of the total. Then, in the following 500,000 years stretching to the top of bed 27, new species appear then disappear with alarming speed. Overall a further 45 species dropped out, one at a time.

Clearly something terrible happened at the base of bed 25 and its ramifications continued for half a million years. But what exactly happened? Fortunately, the Meishan rock section, and other sections elsewhere, contain a record of environmental changes through the Permo- Triassic crisis, in the form of isotopes of oxygen and carbon. Both elements have two stable, naturally occurring isotopes whose ratios fluctuate depending on environmental conditions. The isotope ratios are locked into the skeletons of organisms during their lifetimes, so careful recordings from the shells of bivalves or foraminiferans, for example, can give a detailed picture of atmospheric and oceanic conditions through time.

Oxygen isotopes are used as a palaeothermometer. Oxygen occurs in two forms, oxygen-16 and oxygen-18. These are incorporated into the calcite skeletons of marine creatures at differentrates depending on the water temperature, more oxygen-18at low temperatures, and more oxygen-16 at high. At the base of bed 25, the main mass-extinction level, there was a sudden shift in the oxygen isotope ratios indicating a worldwide rise in temperature of 6C. This may not sound much, but it would have a profound effect on the world's ecology. Climatologists have been getting very excited recently about a half-a-degree rise in global temperatures. The carbon isotopes suggest what might have caused the temperature increase. They show a massive shift towards the light isotope, carbon-12, exactly at the time of the big extinction. Pulses of carbon-12 in the geological record are usually indicative of a volcanic eruption or a large die-off (plants, animals and bacteria concentrate carbon-12 in their bodies and release it when they die). Both certainly happened at the end of the Permian.

But the carbon-12 pulse is far too big to be explained by these mechanisms alone. Calculations of global carbon budgets have suggested that, even if every plant, animal, and microbe died and was buried; altogether they would only account for about one-fifth of the observed carbon shift. The Siberian Traps would have added another fifth. Where did the remaining three-fifths come from?

The extra carbon-12 was probably buried, frozen deep under the oceans in the form of gas hydrates. These are extraordinary accumulations of carbon-12-rich methane locked up in cages of ice at very high pressure. If the atmosphere and oceans warm up sufficiently, these gas reserves can suddenly melt and release their contents in a catastrophic way. The explosion of gas through the surface of the oceans has been termed a "methane burp". A very large methane burp at the end of the Permian could have produced enough carbon-12 to make up the deficit. The cause of the burp was probably global warming triggered by huge releases of CO2 from the Siberian Traps. Methane is a greenhouse gas too, so a big burp raises global temperatures even further. Normally, long-term global processes act to bring greenhouse gas levels down. This kind of negative feedback keeps the Earth in equilibrium. But what happens if the release of methane is so huge and fast that normal feedback processes are overwhelmed? Then you have a "runaway greenhouse". This is a positive feedback system: excess carbon in the atmosphere causes warming, the warming triggers the release of more methane from gas hydrates, this in turn causes yet more warming, which leads to the release of more methane and so on. As temperatures rise, species start to go extinct. Plants and plankton die off and oxygen levels plummet. This is what seems to have happened 251 million years ago. The effects were profound and long-lasting. In the Meishan section, the Permo-Triassic boundary in bed 27 is followed by a succession of dark limestones and shales containing sparse fossils. This seems to represent a post-apocalyptic world; in which CO21evels were still very high and the oceans and atmosphere were starved of oxygen. The 6 per cent of species that survived the initial onslaught were struggling. Normal recovery processes had not yet kicked in. When oxygen levels fall, plants and photosynthesising plankton in the sea normally replenish it by absorbing excess CO2 and generating oxygen. After the crash at the end of the Permian, perhaps oxygen levels had been driven so low, and so much of plant life had been killed, that this was impossible.

The surviving species were a very poor sample of what had lived before: thin-shelled molluscs that required very little food and swam languidly over the black, deoxygenated muds, and the "living fossil" Lingula in its shallow burrows. Near the end of the Permian period, each region of the world had its own fauna and flora. Afterwards, the survivors became cosmopolitan. It took 20 or 30 million years for coral reefs to re-establish themselves, and for the forests to regrow. In some settings, it took 50 million years or more for full ecosystem complexity to recover. Geologists and palaeontologists are only just beginning to get to grips with this most profound of crises.

Michael Benton is head of the Department of Earth Sciences at the University of Bristol. His book on the end-Permian crisis, When Life Nearly Died, has just been published by Thames & Hudson, price 16.95

Copyright 2003, New Scientist

MODERATOR'S NOTE: For more background info on the P/T Controversy go to:
http://abob.libs.uga.edu/bobk/ccc/cc030201.html
http://abob.libs.uga.edu/bobk/ccc/cc030501.html
http://abob.libs.uga.edu/bobk/ccc/cc030601.html
http://abob.libs.uga.edu/bobk/ccc/cc021403.html

============
(2) 'SHOCKING' EXPERIMENT REVEALS HOW ASTEROIDS EXPLODE

From Space.com, 30 April 2003
http://www.space.com/scienceastronomy/watery_meteorites_030430.html

By Robert Roy Britt

Sometimes in science, if you want answers, you just have to bust things up. That's what Kazushige Tomeoka and colleagues did in order to learn why most of the space dust that falls to Earth is wet, while larger space rocks found on the planet are usually dry as a bone.

More than 97 percent of all meteorites collected on Earth's surface lack water. Meanwhile, about 30,000 tons of interplanetary dust reaches Earth's surface every year. Almost all of this dust contains water, resembling the paltry 2.8 percent of known, hydrated meteorites.

"Why is that?" wonders Tomeoka, of the Kobe University in Japan. "There has been no convincing answer to this question."

Scientists have been left to assume that wet space rocks simply don't survive the trip through Earth's atmosphere.

Not buying that explanation, Tomeoka's team decided to figure out what happens in space when asteroids collide. With a specially designed gun -- 16 feet long (5 meters) with a 30 millimeter bore -- they shot meteorites with projectiles moving at up to 4,026 mph (1.8 kilometers per second).

The result was as revealing as it was explosive.

"The application of shock to the watery meteorite reduces it to minute particles and produces explosive expansion upon release of the pressure," Tomeoka told SPACE.com. "In contrast, the dry meteorite does not show significant changes."

The researchers conclude that what's collected on Earth is a result of what happens in space. When watery asteroids are shocked at the surface by an impact -- something that happens to all space rocks several times during their histories -- dust explodes into space. When a dry asteroid is hit by a another rock, not much happens, dustwise.

"As a result of these differences in shock response, watery material would become the predominant kind of dust particles produced by mutual collisions of asteroids, Tomeoka said, adding that larger watery fragments would not be abundant.

Most asteroids roam around the Sun in a belt between Mars and Jupiter. The fragments of their collisions, and the dust, can be drawn toward the inner solar system and sometimes approach Earth. Dust and rocks moving fast in relation to Earth frequently slam into the atmosphere and burn up, generating shooting stars. Stuff moving more slowly relative to Earth can be captured by the planet's gravity and survive the plunge.

The findings will be detailed in the May 1 issue of the journal Nature.

Copyright 2003, Space.com

============
(3) METEORITES UNDER FIRE

From Nature, 1 May 2003
http://www.nature.com/nature/links/030501/030501-4.html

Each year about 30,000 tons of tiny interplanetary dust particles fall to Earth. The composition of most of these micrometeorites is similar to that of the larger hydrated, porous meteorites that reach the Earth's surface. But these make up only 3% of the recovered meteorite falls, the majority being anhydrous. This size-related imbalance was thought to be due to atmospheric filtering. Now by firing a propellant gun at samples from the (hydrous) Murchison and (anhydrous) Allende meteorites, Tomeoka et al. find evidence that the imbalance is established in space, before contact with the atmosphere. Hydrous material shatters over a much broader pressure range than anhydrous, suggesting that collisions between asteroids produce a preponderance of hydrated material in the interplanetary dust.

Interplanetary dust from the explosive dispersal of hydrated asteroids by impacts
KAZUSHIGE TOMEOKA, KOJI KIRIYAMA, KEIKO NAKAMURA, YASUHIRO YAMAHANA & TOSHIMORI SEKINE
Nature 423, 60-62 (2003); doi:10.1038/nature01567

2003 Nature Publishing Group

=============
(4) ASTEROIDAL LAVA FLOWS

From Planetary Science Research, 28 April 2003
http://www.psrd.hawaii.edu/April03/asteroidalLava.html

--- Meteorite studies indicate that we have pieces of lava flows from at least five asteroids.

Written by G. Jeffrey Taylor
Hawai'i Institute of Geophysics and Planetology

Some meteorites are pieces of lava flows. They have the expected minerals present and the crystals are intertwined in a characteristic way indicative of crystallization in a lava flow. This shows that lavas erupted on at least some asteroids. Age dating indicates that the eruptions took place 4.5 billion years ago. Planetary scientists have recognized three main groups of asteroidal lava flows, each distinctive enough to show that they must come from different asteroids. The most abundant are the eucrites, which might actually hail from asteroid 4 Vesta. Mesosiderites are complex mixtures of smashed up volcanic rock and metallic iron. Angrites have a distinctive group of minerals in them, but also clearly formed by volcanism. Recent studies increase the number of groups to five.

David Mittlefehldt (Johnson Space Center) and colleagues Marvin Killgore (Southwest Meteorite Lab) and Michael Lee (Hernandez Engineering, Houston, Texas) show that the five known angrites probably represent at least two different asteroids. Four of the angrites are fairly similar to each other in chemical composition, but a fourth, Angra dos Reis, was very different and may come from an entirely different asteroid. (This is ironic as the group derives its name from Angra dos Reis.) Akira Yamaguchi (National Institute of Polar Research, Tokyo, Japan) and colleagues in Japan at the University of Chicago show that a recently found eucrite, Northwest Africa 011 (NWA 011 for short), has a quite different composition of its oxygen isotopes than the rest of the eucrites. They suggest that NWA 011 comes from a different asteroid than the other eucrites. Thus, it appears that we have samples of lava flows from five different asteroids.


References:
Yamaguchi, A., Clayton, R. N., Mayeda, T. K., Ebihara, M., Oura, Y., Miura, Y., Haramura, H., Misawa, K., Kojima, H., and Nagao, K. (2002) A new source of basaltic meteorites inferred from Northwest Africa 011. Science, vol. 296, p. 334-336.
Mittlefehldt, D. W., Killgore, M., and Lee, M. T. (2002) Petrology and geochemistry of D'Orbigny, geochemistry of Sahara 99555, and the origin of angrites. Meteoritics and Planetary Science, vol. 32, p. 345-369.
--------------------------------------------------------------------------------

Lava Flows and Eruptions on Asteroids

Even big asteroids have fairly puny gravitational fields. This means that we have to modify how we think magma is transported inside these little planets and how lava is erupted. This is not a one-way street, however. Making the adjustments sharpens our understanding of how magma transport and eruptions happen on larger planets. These comparisons are one of the great benefits of planetary science to understanding the Earth.

FULL ARTICLE at
http://www.psrd.hawaii.edu/April03/asteroidalLava.html

===========
(5) BEPPOSAX SATELLITE FALLS HARMLESSLY INTO OCEAN

From Space.com, 30 April 2003
http://www.space.com/missionlaunches/bepposax_falls_030430.html

By Andrew Bridges
AP Science Writer

LOS ANGELES (AP) _ Everything that goes up must come down, including a 3,086-pound Dutch-Italian satellite that splashed into the Pacific Ocean seven years after being sent into space.

The BeppoSAX satellite re-entered the Earth's atmosphere around 5:57 p.m. EDT Tuesday, mission member Giovanni Mussoni said by phone from Rome.

It fell in the equatorial Pacific with the debris closest to land splashing down about 186 miles northwest of the Galapagos Islands. 

``The important thing is it fell in the Pacific,'' Mussoni said.

The Agenzia Spaziale Italiana initially put 39 countries on notice that portions of BeppoSAX could come down on their territory.

But the odds were always greatest that the fragments would splash harmlessly into the ocean, said William Ailor, director of The Aerospace Corp.'s Center for Orbital and Reentry Debris Studies in El Segundo.

The Italian space agency estimated that as much as 1,325 pounds of the satellite would survive the fiery passage through the atmosphere and rain down on Earth. Those fragments were expected to include chunks of stainless steel and titanium weighing as much as 220 pounds.

BeppoSAX's end came nearly seven years to the day after its April 30, 1996, launch. The Earth-orbiting, X-ray observatory is best known for its discovery of 50 gamma-ray bursts, explosions more powerful than anything known since the Big Bang.

The satellite was switched off April 30, 2002.

As many as 100 basketball-size and larger human-made objects fall to Earth each year. Only one person is known to have ever been struck by orbital debris -- an Oklahoma woman who was not injured, Ailor said.

Copyright 2003, Space.com

============
(6) H. JAY MELOSH ELECTED TO NATIONAL ACADEMY OF SCIENCES

From Ron Baalke <
baalke@zagami.jpl.nasa.gov >

From Lori Stiles, UA News Services, 520-621-1877
April 30, 2003

University of Arizona Professor H. Jay Melosh of the Lunar and Planetary Laboratory (LPL) has been elected to the National Academy of Sciences, one of the most prestigious honors in American science.

The Academy, chartered in 1863 by President Abraham Lincoln to guide public action in science, yesterday elected 72 new members and 18 foreign associates from 11 countries in recognition of their distinguished and continuing achievements in original research.

"Jay Melosh literally wrote the book on impact cratering," said Michael Drake, head of the LPL and UA planetary sciences department. "His 1989 book made us all aware of the importance of extraterrestrial impacts in shaping our Earth. The book ("Impact Cratering: A Geologic Process," Oxford University Press) is still the universal reference used by all scholars."

-----------------------------------
Contact Information
H. Jay Melosh
520-621-2896
jmelosh@lpl.arizona.edu

Michael Drake
520-621-6962
drake@lpl.arizona.edu
------------------------------------

Melosh said he learned of his election at 8 a.m. yesterday, when he logged on his computer to check for an important e-mail message.
He said he didn't expect this one, from UA Regents' Professor and NAS member J. Randy Jokipii, informing him of his election to the Academy.
About an hour later, Melosh said, Jokipii reached him by phone from a cab near a Washington, D.C., airport.
"Randy says he tried to get me out of bed with news at 7 a.m. (he would not have!), but had to settle for e-mail because my home number in the LPL phone listings is incorrect."
"I've been getting lots of phone calls, lots of e-mails. It is really amazing," Melosh said. "I'm somewhat surprised. I figure I'd never be elected because the science I do is sometimes controversial. It tends to rock the boat."
Melosh said he is reluctant to compare or rank the honors he has been given, but admits that "this one is certainly way up there."
"Jay's work has helped us understand the origin of the Moon in a giant impact of a Mars-sized object with the growing Earth. Jay figured out how we get meteorites from the Moon and Mars, helping us understand that we had 'free' space missions courtesy of mother nature," Drake said.
"He has shown how impacts into the ocean cannot cause havoc the way depicted in movies like Deep Impact - hint: giant waves break way out to sea and dissipate their destructive energy by the time they reach shore.
"He has shown how the dinosaurs and most species on Earth perished 65 million years ago when a large impact into what is now Mexico ejected material up through the atmosphere. This material reentered the atmosphere like ballistic missiles, heating the atmosphere to hotter than a conventional oven can achieve, thereby burning plants, animals, and trees globally," Drake said.
"Jay has shown how enormous landslides travel tens of miles down very shallow slopes. I could go on, but his contributions to knowledge are extraordinary.
"Add to this scholarship the fact that he is an extraordinary teacher, and he represents everything the State of Arizona would want in a faculty member.
"He is also precisely the type of faculty member who could be recruited by another university because of the short-sighted budgetary recommendations of the legislature these past few years," Drake said. "The erosion of the university's budget must be reversed if we are to retain scholars of the caliber of Jay Melosh."
Melosh graduated magna cum laude with a bachelor of arts degree in physics from Princeton University in 1969, and earned his doctorate in physics and geology from Caltech in 1973. He joined the UA faculty in 1982, where he has supervised 12 doctoral students in planetary sciences.
Melosh is author or co-author of more than 150 scientific papers and has served on numerous national and international committees and panels that guide scientific planning, publications, facilities, and awards in his discipline. His numerous awards and fellowships most recently include the Barringer Medal of the Meteoritical Society (1999), Asteroid 8216 "Melosh" approved by the International Astronomical Union (2000), the Gilbert Medal of the Geological Society of America (2001), and Fellow of the American Association for the Advancement of Science (2001).
Melosh is on the 12-member science team for Deep Impact, a $279 million robotic mission that will become the first to penetrate the surface of a comet when it smashes its camera-carrying copper probe into Comet Tempel 1 on July 4, 2005.

============================
* LETTERS TO THE MODERATOR *
============================

(7) BRAVO SLOAN AND AIAA

From Andy Smith <
astrosafe22000@yahoo.com >

Hello Benny and CCNet,

The large survey telescopes (LST) can make a very important contribution to the search for the dangerous near-earth objects (NEO) that threaten us...especially those smaller than magnitude 20. We were therefore delighted to see the recent announcement of the 2nd Release of the Sloan (SDSS) Digital Sky Moving Object Catalog. We salute Zeljko Ivezic and all who contributed to this outstanding work (134,335 observations, 26,847 orbital elements). We also encourage the other LST teams, around the world, to join in helping to meet this vital challenge.

Planetary Defense Conference

We also want to thank the American Institute of Aeronautics and Astronautics (AIAA) and the Aerospace Corporation for sponsoring the upcoming Planetary Defense Conference (California, next February). This landmark conference will focus on asteroid/comet impact prevention, civil emergency preparedness, etc. and we encourage the global technical community to make submissions and to participate. Abstracts must be sent before July 2003. It would be especially beneficial, to the global effort, to hear of new activities by Spaceshield Foundation institutions and specialists.

The conference organizers have devoted a major effort to organizing and defining the conference sessions and we will be happy to assist any CCNet participants who wish to attend. It may be possible to obtain limited translation services, if they are needed. We have been very impressed with the planning team and are looking forward to an outstanding conference. We also hope
they will make the abstracts and papers available on the Web...to join the excellent files from the 1995 Planetary Defense Workshop, the Spaceshield PDE Conferences and other outstanding technical meetings on this vital subject.

Earth & Space 2004

We are also assisting the Amercian Society of Civil Engineers (ASCE) to organize Earth & Space 2004, in Houston, Texas, next March. This conference will emphasize structural issues  and robotics and we are hoping to continue and to advance the dialogue on tsunami-resistant structures and on planetary defense, in the Houston community.

These conferences provide an excellent opportunity to inform the policy makers, the technical media and many other important groups of the issues and needs related to planetary protection...and we value them highly.

4th Generation Asteroid Telescopes

Plans for the very promising next generation of asteroid telescopes are moving forward, at an
encouraging pace, and we invite the CCNet community to examine the additions to the web pages for the POI (Air Force, U. Hawaii et al) and the LSST (Dark-Matter Telescope). These programs should open the door to the identification of that large population of smaller...but extremely dangerous...NEO. They feature a new generation of CCD cameras and could make it possible to complete the critical inventory in a decade (instead of more than a century)....working in cooperation with our excellent family of active NEO search teams.

Cheers
Andy Smith/IPPA 
astrosafe22000@yahoo.com

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