[meteorite-list] Looking Out For Nature's Weapons of Mass Destruction

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:17:45 2004
Message-ID: <200312121726.JAA04448_at_zagami.jpl.nasa.gov>

http://www.inform.umd.edu/News/Diamondback/archives/2003/12/12/news8.html

Looking out for nature's weapons of mass destruction

University astronomer warns about danger from above

By Jeremy Hsieh
The Diamondback (University of Maryland)
December 12, 2003

Spectacles like the Geminid meteor shower, which will peak tomorrow night, act
as harmless, natural light shows for stargazers.

It's the bigger things that have fallen - and will fall again - from the sky
that worry Lucy McFadden, university associate professor of astronomy.

McFadden was one of 13 space experts to sign a letter warning Congress in July
to invest in the early detection of asteroids and comets passing near the Earth,
also known as Near Earth Objects.

"When I first started studying in this field 30 years ago ... we knew these things
were passing near Earth, but we didn't really appreciate their threat," McFadden
said.

The 1994 impact of the Shoemaker-Levy 9 comet on Jupiter served as a wake-up call
to space scientists around the world. The letter described the impact of the
explosion as being as powerful as a billion megatons of TNT. In the aftermath, a
dust cloud larger than the size of Earth swelled in Jupiter's atmosphere.

"It sort of dawned on us that this happens," McFadden said.

The letter to Congress is one of the latest steps space scientists have taken to
increase awareness of the extraterrestrial threat. McFadden said officials should
prepare for an NEO impact in the same ways they prepare for other disasters.

"It's just adding to our list of natural disasters," McFadden said.

And such a disaster is a statistical inevitability.

"We cannot rely on statistics alone to protect us from catastrophe; such a strategy
is like refusing to buy fire insurance because blazes are infrequent," the letter's
authors wrote. "Our country simply cannot afford to wait for the first modern
occurrence of a devastating NEO impact before taking steps to adequately address
this threat.

"If space research has taught us anything, it is the certainty that an asteroid or
comet will hit Earth again," the letter's authors wrote. "Impacts are common events
in Earth's history: Scientists have found more than 150 large impact craters on our
planet's surface. Were it not for Earth's oceans and geological forces such as
erosion and plate tectonics, the planet's impact scars would be as plain as those
visible on the moon."

But why appeal to the U.S. government to save the world?

"There's the problem," McFadden said. "There's no structure [for dealing with
planetary defense]. Whose responsibility is it to protect the planet? NASA is an
exploration agency. [The Federal Emergency Management Agency] is for helping
people after the fact."

The decision to appeal to Congress to invest in NEO precautions was somewhat
arbitrary, stemming from American ethos, McFadden said.

The letter's signatories focused their letter on stepping up the monitoring of
space for NEOs, but did not offer concrete solutions for destroying or deflecting
potential NEOs detected on a collision course with Earth.

"Do I think it's worth spending billions of dollars on designing something [to
destroy or deflect NEOs]?" McFadden asked, rhetorically. "Eh. I'd rather explore
the solar system."

The full contents of the letter are available at http://www.congressneoaction.org.
Received on Fri 12 Dec 2003 12:26:48 PM PST