[meteorite-list] NASA Report: Expand Search to Include Small Asteroids

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:29:53 2004
Message-ID: <200309110126.SAA04676_at_zagami.jpl.nasa.gov>

http://space.com/scienceastronomy/asteroid_search_030910.html

NASA Report: Expand Search to Include Small Asteroids
By Robert Roy Britt
space.com
10 September 2003

A panel of experts working at NASA's request has recommended a bold new
search for potentially dangerous asteroids, including smaller objects that
could cause regional damage in an Earth impact.

The price tag: At least $236 million.

The recommendation for a search effort far more expensive than the existing
asteroid detection program, appears to have strong support among asteroid
experts.

NASA already leads the way in hunting for large Near Earth Objects (NEOs)
that could cause global destruction. That effort, mandated by Congress, will
be in the mop-up phase by 2008. NASA spends about $3.5 million per year on
the program.

Critics have long charged that NASA and other government agencies around the
world are not doing enough to look for smaller NEOs, those less than 0.62
miles (1 kilometer) in diameter. Though the smaller rocks would only have
regional consequences, there are more of them so the chances of an impact
are higher, the critics reason.

But the smaller rocks are harder and more costly to find.

The more refined hunt should start in 2008, the panelists conclude. It could
be done with present technology and could find and catalogue 90 percent of
potentially threatening objects down to 153 yards (140 meters) by 2028.

The "Near-Earth Object Science Definition Team" report was published to a
NASA web site yesterday with no fanfare.

"The report's recommendations are not only in line with what we have been
arguing for some time -- it surpasses our expectations by far," said Benny
Peiser, a researcher at Liverpool John Moores University in the UK.

Peiser has been a vocal critic of his own government's lack of spending on
asteroid detection and of other governments' unwillingness to begin looking
for smaller objects.

The new report does not bind NASA into action, but astronomers are hopeful
it will be the roadmap for an expanded effort to provide warning of
potential future catastrophes. No asteroids are currently known to be on a
collision course with the planet.

"I'm hopeful the pressure will be brought to bear to initiate this next
generation of search," Donald Yeomans, vice-chair of the report, said in a
telephone interview. The pressure, he said, would have to be applied to
congressional staffers by astronomers and the public.

Yeomans is head of the Near Earth Object Program Office at NASA's Jet
Propulsion Laboratory (JPL). He said the panel's diverse make-up -- 12
members from nine public and private institutions and the U.S. Air Force --
should translate into broad acceptance among astronomers.

An asteroid twice the size of a football field (140 meters) or bigger is
thought to hit Earth about every 15,000 to 20,000 years, Yeomans said.

The search could be conducted either from the ground or from space. If
ground-based, it would take 20 years and cost $236 million. If space-based,
the price tag would jump to $397 million but the time frame would shrink to
just seven years. Yeomans said in either case the estimates are
conservative. Innovative efforts could yield better results.

The report does not specify which method should be used.

Top NASA officials are not fond of investing in ground-based astronomy,
however. They believe, in general, that such efforts should fall to the
National Science Foundation and other institutions. All of the present
asteroid search programs -- including those funded by NASA -- are done from
the ground, though.

The report says the next logical step would be for NASA to issue an
Announcement of Opportunity that would serve as a vehicle to collect firm
cost estimates for various possible search systems.

Peiser said the report is a perfect antidote, coming a week after an
asteroid scare was generated in the media when one space rock's long odds of
a future impact were overblown.

Astronomers broadly agree that by finding 90 percent of all NEO's 140 meters
and larger would answer, one way or the other, whether Earth is due for an
impact anytime in the foreseeable future.

Even smaller objects can cause local damage, but most analysts agree they
are too numerous to warrant the investment of precious financial resources
anytime soon.

"We have the technology now to essentially solve the asteroid impact hazard
for good within the next one or two generations," Peiser told SPACE.com.
"And it's not even as expensive as some skeptics have thought. Accepting
these recommendations would be NASA's perfect opportunity to get back on
their feet and show the world that American space policy has neither lost
its vision nor its no-nonsense approach that is tremendously popular both in
the U.S. and around the world."
Received on Wed 10 Sep 2003 09:26:55 PM PDT