CCNet 86/2003 - 15 October 2003

Why be at the mercy of a menacing asteroid that has Earth in its cross hairs?
Now an expert team of astronauts and space scientists has blueprinted a safety
strategy for Earth: an asteroid tugboat. The group says NASA is already working
on the right recipe of technologies to make the tug a reality. It would be the
greatest public safety project in history. Furthermore, they propose a mission
to demonstrate the asteroid-tug concept by 2015.
       --Leonard David,, 15 October 2003


    Scientific American, November 2003

    NASA Science News for October 10, 2003

    Pål Brekke <>

    Michael Paine <>

    Paul V. Heinrich <>

    Göran Johansson <>

    Washington Post, 12 October 2003


By Leonard David

BOULDER, Colorado -- In the grand cosmic scheme of things, it's only a matter of time. Our planet is bound to tangle with an Earth-crossing asteroid, an event sure to make a mess. Some of these space rocks could demolish a city. Other monster boulders, the really big bruisers, could snuff out our civilization.

But why be at the mercy of a menacing asteroid that has Earth in its cross hairs? Now an expert team of astronauts and space scientists has blueprinted a safety strategy for Earth: an asteroid tugboat. The group says NASA is already working on the right recipe of technologies to make the tug a reality. It would be the greatest public safety project in history. Furthermore, they propose a mission to demonstrate the asteroid-tug concept by 2015.

Details of the asteroid tug are unveiled in the November 2003 issue of Scientific American.

Lead author of the article is former astronaut, Rusty Schweickart, Apollo 9's lunar module pilot that put the Moon landing craft through its paces high above Earth in March 1969. Other contributors are Piet Hut, Professor of Interdisciplinary Studies at the Institute for Advanced Study in Princeton, New Jersey, and asteroid specialist, Clark Chapman of the Southwest Research Institute here in Boulder. 

One more co-author is NASA astronaut Edward Lu. He is now resident onboard the International Space Station and, in fact, e-mailed final article edits on behalf of his fellow writers while circling Earth.

The asteroid tug test project is dubbed the B612 mission. That's the name of the asteroid in The Little Prince, the well-known young person's book by Antoine de St. Exupery. In fact, late last year, Schweickart, Lu, Hut and Chapman formed the B612 Foundation, a nonprofit group dedicated to developing and demonstrating the capability to deflect asteroids from Earth.

The premise behind the proposal, however, is no child's play. It's a way to ward off the doomsday rock that will sooner or later terrorize humanity.

Ugly date with Earth

Over the years, numbers of schemes to deal with bully asteroids have been proposed. Among them is blasting the beast to smithereens via a nuclear bomb. Another thought is planting a nuclear device on one side of the asteroid, then detonating the bomb to accelerate the space rock slightly in the opposite direction.

"The problem, however, is that the results are neither predictable nor controllable," Schweickart and his colleagues suggest. Also, such an explosion could split the asteroid into pieces, leaving multiple headaches of heavenly flotsam.

Then there's the kamikaze approach. Just crash a large robotic spacecraft into a worrisome asteroid at high speed. This too has its problems. Namely, you could just spin the body or knock off a small chip.

Other ideas are reviewed by the B612 think team and are highlighted in the Scientific American article. In their view, an asteroid is a "push over"… push it just enough to miss an ugly date with Earth.

Given enough warning time, an asteroid tugboat could nestle up to the mini-world, then provide long stints of gentle pressure. The tug would nudge the asteroid ever so slightly, but enough to shift the space rock's orbit so an Earth collision is averted.

Mission possible

The B612 test mission to deflect an asteroid could use Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engines. The VASIMR propulsion unit employs radio waves to ionize a gas and accelerate the plasma to even higher exhaust velocities. Veteran shuttle astronaut, Franklin Chang-Diaz, is exploring this novel, low-thrust propulsion technology.

Other equipment ideal for steering into the B612 project is scattered throughout NASA. Specifically, the space agency's Prometheus Project to design a space-rated nuclear reactor is a plus for any asteroid deflection scheme. Work is underway for a Prometheus flagship mission - the Jupiter Icy Moons Orbiter (JIMO). Hardware stemming from JIMO, the nuclear power plant, radiator panels, a lengthy truss, and other equipment could help nurture the asteroid tug into being.

The practice B612 mission would verify maneuvering around a target asteroid, rendezvousing with and then attaching itself to the body. No easy set of job tasks.

Additionally, the tug would have to hold tight to its target asteroid. Procedures to deal with a spinning body would have to be ironed out. Once secure to the space rock -- some 655 feet (200-meters) wide -- the tug must use onboard engines for months to accelerate the asteroid in the desired direction.

According to Schweickart and his fellow asteroid tug advocates, the training mission would have a price tag of about $1 billion. They believe that this extraterrestrial exercise could be accomplished by 2015.

"By practicing an asteroid deflection, the B612 mission would show whether the asteroid-tug concept is feasible and, if so, how it should be refined in the event of a real impact threat," the study team writes.

Schweickart told that the B612 proposal is meant to educate public and political communities to the fact that Earth-approaching asteroids are a natural, environmental threat. "Unlike earthquakes, hurricanes, etc., we can actually do something about them. The capability to take this action is within reach of today's -- or tomorrow's -- technology," he said.

Schweickart said the cost of a trial-run asteroid tug mission is quite modest and well within the capability of the NASA budget to handle. 

"However, the expenditure necessary to establish an operational system it will require both money and international coordination," Schweickart added, "and both will require a level of determination and commitment that may be hard to come by without strong and clear demand by the general public."

False alarms

Just how much serious attention can the B612 proposal hope to garner?

One factor that might cause more a yawn than action is the number of on-again/off-again threats from the sky. Those are the already numerous predictions and projections that later turned out not to be sure bets.

"Of course, we want our response to the impact threat to be part of a serious, objective approach to a considered evaluation of what the threat is," explains asteroid specialist, Clark Chapman.

"So we don't like the irresponsible treatment of the threat by some individuals and some -- especially British -- news media, although we understand the psychological difficulties of dealing with tiny probabilities of horrible events," Chapman said. On the other hand, he noted that "any news is good news".

"I am not specifically aware of important decision-makers holding views that have explicitly changed -- in either direction -- as a result of the false alarms," Chapman explained.

Wanted: serious consideration

The general message from B612, Chapman concluded, is to try and develop, with private funds, an exciting and important demonstration project that will robustly bring everyone up the learning curve of what to do if a threatening Near Earth Object is eventually found to be heading Earth's way.

"We hope that public concerns about this issue can be translated into real financial contributions to bring these concepts to a point where we could expect serious consideration by one or more space agencies…agencies that have not yet officially put asteroid mitigation into their plans," Chapman noted.

Chapman said that NASA's current Prometheus Project looks like an approach to deep space missions that would be particularly well suited to the B612 proposal.

"Obviously, beyond the mere demonstration of engineering that could conceivably 'save the planet' -- or at least a small part of the planet -- there would be dramatic opportunities to learn about how to deal with a nearly gravity-free body in space," Chapman said, "both to scientifically study asteroids and meteorite parent bodies and to consider eventual asteroid mining operations."

Copyright 2003,


Scientific American, November 2003
To prevent an asteroid from hitting Earth, a space tug equipped with plasma engines could give it a push

By Russell L. Schweickart, Edward T. Lu, Piet Hut and Clark R. Chapman

On an average night, more than 100 million pieces of interplanetary debris enter Earth's atmosphere. Luckily, most of these bits of asteroids and comets are no bigger than small pebbles; the total weight of the 100 million objects is only a few tons. And our planet's atmosphere is thick enough to vaporize the vast majority of these intruders.

So the debris usually streaks harmlessly overhead, leaving the bright trails popularly known as shooting stars.

When bigger objects slam into the atmosphere, however, they explode rather than vaporize. In January 2000, for example, a rock about two to three meters wide exploded over Canada's Yukon Territory with a force equivalent to four or five kilotons of TNT. This kind of event occurs once a year, on average. Less frequently, larger rocks produce even more powerful explosions. In June 1908 a huge fireball was seen descending over the Tunguska region of Siberia. It was followed by an enormous blast that flattened more than 2,000 square kilometers of forest. The consensus among scientists today is that a rocky asteroid about 60 meters in diameter exploded some six kilometers above the ground with a force of about 10 megatons of TNT. The blast wave devastated an area approximately the size of metropolitan New York City....continued at Scientific American Digital


NASA Science News for October 10, 2003

An unusual double Leonid meteor shower is going to peak next month over parts of Asia and North America.
October 10, 2003: The Leonid meteor shower is coming. Twice.

Bill Cooke of the Space Environments Group at the NASA Marshall Space Flight Center explains: "Normally there's just one Leonid meteor shower each year, but this year we're going to have two: one on Nov. 13th and another on Nov. 19th."

Both are caused by comet Tempel-Tuttle, which swings through the inner solar system every 33 years. With each visit the comet leaves behind a trail of dusty debris--the stuff of meteor showers. Lots of the comet's old dusty trails litter the mid-November part of Earth's orbit.

"Our planet glides through the debris zone every year," says Cooke. "It's like a minefield. Sometimes we hit a dust trail, sometimes we don't." Direct hits can spark a meteor storm, which is defined as more than 1000 shooting stars per hour. "That's what happened in, for example, 1966 and 2001," says Cooke. "Those were great years for Leonids."

"This year we're going to brush past two of the trails--no direct hits," he says. Even so, "we might have a nice display."

The first shower is expected on Nov. 13th around 17:17 UT. For about three hours centered on that time Earth will be close to some dust shed by Tempel-Tuttle in the year 1499. Sky watchers in Alaska, Hawaii and along the Pacific rim of Asia are favored. They'll see anywhere from a few to 40 meteors per hour--"if they can avoid the glare from that night's gibbous Moon," cautions Cooke. A good strategy for moonlit meteor observing: travel to high altitudes where the air is clear or stand in the shade of a tall building or hillside.



Pål Brekke <>

SOHO will be celebrating the 8th Anniversary of its launch on 2 December 2003.
To help commemorate this event, a Top 10 list of SOHO's images will be featured
on the astronomy web site, with a related article about SOHO's
achievements.  We want you to help us decide which images to feature.  On our
voting page you will see 30 thumbnails of our favorite SOHO images (click on any
of them to make them larger).  All you have to do is tell us which five of the
images you like the most.  Just click in the "VOTE" box under five of these
images, then click "Submit votes".  The voting will end on 17 November.  The
results will be posted on 25 November on, and will be available here a
day later.

Full story and how to vote here. You can win som nice prizes by participating.

Dr. Pål Brekke       |         Tel: +1-301-286-6983
SOHO Deputy Project Scientist       |         Mob: +1-301-996-9028
European Space Agency       |         Fax: +1-301-286-0264
NASA Goddard Space Flight Center      |
Mail Code 682.3, Bld. 26,  Room G-1   |
Greenbelt, MD 20771, USA.       |


Michael Paine <>

Dear Benny

See these articles
Michael Paine (600K PDF)
Richard R. Donofrio, Research Associate, Petroleum and Astrogeology,
Exploration and Development Geosciences [EDGe], University of Oklahoma,
Norman, Oklahoma, August 2003
It has been one year since the announcement of the Silverpit discovery
in the British journal, Nature. EDGe would like to set the record
straight about a key cross-section, which was used in the Silverpit
interpretation. Briefly, to review the events that led to the Silverpit
discovery, it appears that two British geoscientists, Simon Stewart of
British Petroleum and Phillip Allen of Production Geoscience Ltd., were
working on some reprocessed North Sea seismic and noticed an unusual
buried structure. They were perplexed, until they came across an article
written by this author. Two months after the announcement of the
Silverpit discovery in the August 1, 2002 issue of Nature (“A
20-km-diameter multi-ringed impact structure in the North Sea”), Phillip
Allen mentioned in correspondence,“I owe you one. It was only when
someone (Simon Stewart I think) showed me your illustration in [sic] Oil
& Gas Journal (1998) that I was convinced that we had an impact!” We
Yanks are proud to say that the article Mr. Allen is referring to has
been available here at EDGe News for the past five years, courtesy of
the U.S. Oil & Gas Journal. It is a cover-story article showing an
impact collision into an ocean, which appeared in the May 11, 1998
issue. The illustration of interest shows the structural profile of a
complex-type impact crater, which was used by the Brits to interpret the
Silverpit seismic. The article was first published a year earlier under
a different title by the Oklahoma Geological Survey in Circular 100,
1997 (the impact structure papers in that circular are from a 1995
symposium at the University of Oklahoma). For some reason, the Brits in
their Nature publication did not show the illustration or mention the
Oil & Gas Journal or Oklahoma Geological Survey articles. EDGe thanked
Mr. Allen for his compliment about the illustration back in November
2002 in the notes of an online article titled “Bay of Biscay Feature:
Multiringed?” (see EDGe News link at end). The Bay of Biscay article
contains seismic cross-sections of Silverpit. Readers can compare these
to the Oil & Gas Journal and Oklahoma Geological Survey impact crater
illustrations (the best comparison is with images of similar scale and
inclination). We’ve seen many different structural and seismic profiles
of astroblemes over the years, but Silverpit is multi-ringed and
captivating. EDGe is developing a synthetic seismic profile of Silverpit
for a later article, and we look forward to sharing our expertise in
astrogeology with our fellow Brits and others.
c2003 EDGe
(See also other news items at )
A Hydrothermal System Associated with the Siljan Impact Structure,
Sweden - Implications for the Search for Fossil Life on Mars
Tomas Hode, Ilka von Dalwigk, Curt Broman
Astrobiology      Volume: 3 Number: 2 Page: 271 -- 289
Abstract: The Siljan ring structure (368 ± 1.1 Ma) is the largest known
impact structure in Europe. It is a 65-km-wide, eroded, complex impact
structure, displaying several structural units, including a central
uplifted region surrounded by a ring-shaped depression. Associated with
the impact crater are traces of a post-impact hydrothermal system
indicated by precipitated and altered hydrothermal mineral assemblages.
Precipitated hydrothermal minerals include quartz veins and breccia
fillings associated with granitic rocks at the outer margin of the
central uplift, and calcite, fluorite, galena, and sphalerite veins
associated with Paleozoic carbonate rocks located outside the central
uplift. Two-phase water/gas and oil/gas inclusions in calcite and
fluorite display homogenization temperatures between 75°C and 137°C.
With an estimated erosional unloading of ~1 km, the formation
temperatures were probably not more than 10-15°C higher. Fluid inclusion
ice-melting temperatures indicate a very low salt content, reducing the
probability that the mineralization was precipitated during the
Caledonian Orogeny. Our findings suggest that large impacts induce
low-temperature hydrothermal systems that may be habitats for
thermophilic organisms. Large impact structures on Mars may therefore be
suitable targets in the search for fossil thermophilic organisms.
Copyright © by Mary Ann Liebert, Inc. 2003
=========== LETTERS ===========


Paul V. Heinrich <>

Benny Peiser

Your listmember might be interested in
the article "Possible Meteorite Impact
Crater in St. Helena Parish, Louisiana"
that can be found at:

the original article can found on pages
3 - 5 of the June 2003 issue of
Louisiana Geological Survey News at:

Since the above article was published,
in situ shocked quartz has been found
samples from highly fractured Citronelle
Fm. lying beneath rim deposits.

A full paper will be published in the
2003 volume Transactions of the Gulf
Coast Association of Geological Societies.

An abstract of the paper can be found
in "Abstracts (By Author) Gulf Coast
Association of Geological Societies
53rd Annual Convention, Baton Rouge, LA,
October 22-24, 2003 Hosted by Baton
Rouge Geological Society" at:

and under "Origin of a Circular
Depression and Associated Fractured
and Shocked Quartz, St. Helena Parish,
LA by Paul V. Heinrich" at:


Paul V. Heinrich
Baton Rouge, LA


Göran Johansson <>

Dear Benny,

On October 9, Daniel Fischer asked for comments about the possibility that Ephesos was
founded after a meteorite impact. The following is from a posting by myself on January 30
last year.

"But from summer, 3rd year of Murshilish II, we have an interesting story. It is quoted
in Younger, Ancient Conquest Accounts, page 208. The king was marching with his army towards
the west when they observed a meteor. The city Apasa (Ephesus?) was struck by it."

This should be about 3320 years ago. If Ephesos and Apasa were the same cities, then Ephesos
was founded before a memorable impact.

Göran Johansson


Washington Post, 12 October 2003

By Lee Hockstader

NEW ORLEANS -- So a meteorite crashes through your roof, pulverizes a bedroom upstairs, obliterates a powder room downstairs and splinters into pieces in the crawl space beneath your house.

Now what?

You are not necessarily having a bad day. Provided you are not flattened like a pancake, you might even get rich. But you may want to start screening your calls and doing some homework, because you have just become a bit player in a multimillion-dollar enterprise -- the strange, impassioned, big-budget commerce in interplanetary objects.

That is what Roy and Kay Fausset, owners of a New Orleans gift shop, have been learning since they came home from work on Sept. 23, opened the front door and were confronted by what insurers would regard as "an act of God."


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