[meteorite-list] Earth Playing Cosmic Roulette With Asteroids

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:06:55 2004
Message-ID: <200210040149.SAA16636_at_zagami.jpl.nasa.gov>

Committee on Science
U.S. House of Representatives
SHERWOOD BOEHLERT, CHAIRMAN
Ralph M. Hall, Texas, Ranking Democrat

Press Contacts:
Heidi Mohlman Tringe, Heidi.Tringe_at_mail.house.gov
Jeff Donald, Jeffrey.Donald_at_mail.house.gov
(202) 225-4275

October 3, 2002

107-295

EARTH PLAYING COSMIC ROULETTE WITH ASTEROIDS

WASHINGTON, D.C. -- Scientists are making progress in
cataloguing and tracking large near-earth objects (NEOs), but
a serious threat still remains from smaller objects, an expert
panel told the Space and Aeronautics Subcommittee today.

These smaller asteroids (200-500 meters wide) could potentially
demolish a city with a direct hit or cause a tsunami capable
of wiping out entire coastal areas if they land in the ocean.
NASA has catalogued nearly 50 percent of asteroids 1 kilometer
wide and larger. Astronomers estimate that between 900 and
1300 of the larger asteroids exist while there could be as
many as 50,000 in the smaller range.

Subcommittee Chairman Dana Rohrabacher (R-CA) stated, "The
threat posed by incoming asteroids and comets is a serious,
potentially life-threatening topic. Given the number of
near-earth objects in space, it is a matter of time before
we are faced with an event unparalleled in human history.
I hope that my legislation, H.R. 5303
[http://www.house.gov/science/press/107/107-286.htm], passed
by the House on Tuesday will strengthen existing government
capabilities for tracking natural space objects by
encouraging private citizens to observe asteroids and
comets."

Subcommittee Ranking Member Bart Gordon (D-TN) added, "NASA's
Mission Statement says that part of its mission is '... to
protect our home planet.' I hope NASA will heed the message
of today's hearing and work with other agencies of the U.S.
government to craft a timely, cost-effective plan to detect
and catalog as many as possible of the Near-Earth asteroids
and comets that could potentially threaten our population.
We cannot afford to be complacent."

Dr. David Morrison, senior scientist at the NASA Ames
Research Center, discussed NASA's goals and accomplishments
in monitoring NEOs through the "Spaceguard" program.
Morrison noted that Spaceguard was halfway to its goal
and he expected that by 2008 NASA will have 90 percent of
large, kilometer-sized threatening asteroids catalogued.
Morrison added, "Our objective should be to find a large
impactor far in advance, and thus provide decision-makers
with options for dealing with the threat and defending our
planet from cosmic catastrophe."

NEOs also pose a serious concern for the military, Brigadier
General Simon P. Worden testified. Worden told of an
asteroid that entered the atmosphere and exploded above the
Mediterranean during last year's India-Pakistan conflict.
U.S. satellites detected an energy release and shockwave
comparable to the Hiroshima bomb, and Worden explained that
had the event taken place at the same latitude two hours
earlier and mistaken for a nuclear detonation it could have
had devastating consequences. Worden added, "I believe
there is considerable synergy between national security
requirements related to man-made satellites and global
security requirements related to NEO impacts."

Witnesses also debated the merits of continuing the
cataloging effort on smaller NEO's once the Spaceguard
program is completed. Dr. Brian Marsden, Director of the
Minor Planet Center of the Smithsonian Astrophysical
Observatory, testified that handling the large amount of
data from surveys of smaller NEOs would be a challenging,
but feasible, task. Dr. Joseph Burns, a member of the
Solar System Exploration Survey Committee of the National
Research Council, testified that NASA should partner with
the National Science Foundation to build and operate a
large ground-based survey telescope because of NSF's
expertise in ground based astronomy and NASA's traditional
support of ground-based solar system observations that
support space missions.

Dr. Ed Weiler, NASA Associate Administrator for Space
Science, disagreed saying, "I feel that it is premature
to consider an extension of our current national program
to include a complete search for smaller-sized NEOs." He
also noted that NASA did not feel the agency "should play
a role in any follow-on search and cataloging effort
unless that effort needs to be specifically space-based
in nature."

Rep. Anthony Weiner (D-NY) said, "For too long we've assumed
that the worst asteroid risk would come from Hollywood -- in
the form of a sequel to flops like Deep Impact or Armageddon.
But the threat posed by Near Earth Objects is real, and if
we can plow $100 million into a summer flick, we can
certainly give NASA the means to make us safer from real
life blockbusters."

Witness testimony and an archived web cast of the proceedings
can be found at
     http://www.house.gov/science/

*****

COMMITTEE ON SCIENCE
U.S. HOUSE OF REPRESENTATIVES
2320 RAYBURN HOUSE OFFICE BUILDING
WASHINGTON, DC  20515
(202) 225-7858

Hearing:

The Threat of Near-Earth Asteroids
 
Thursday, October 3, 2002  10:00 a.m.
2318 Rayburn House Office Building

1. Purpose of Hearing 
 
On Thursday, October 3, 2002, at 10:00 a.m. in room 2318 of
the Rayburn House Office Building, the Subcommittee on Space
and Aeronautics will hold a hearing on the threat of Near-
Earth Asteroids.  The hearing will examine the status of the
current national survey of asteroids and comets known as
Near-Earth Objects ("NEOs"), the threat of a NEO impact,
future goals for the survey, and the national policy regarding
NEOs. 
 
Asteroids and comets with orbital distances from the sun
similar to Earth's are designated as NEOs.  While many of
these pose no threat of collision with the Earth, a subset
known as "Earth-crossing asteroids" (ECAs) and "potentially
hazardous asteroids" (PHAs) have orbits with the potential
for a close encounter or collision with the Earth.  The
Earth is bombarded by small meteorites every day, but most
of these objects are less than 50 meters in size and burn
up in the atmosphere.  Larger objects impact the Earth less
frequently but can cause enormous damage depending on their
size, as described in Figure 1.  For example, scientists
now generally believe that the mass extinction at the end
of the Cretaceous period, which included dinosaur extinction,
was the result of climate and ecosystem disruption from a
massive asteroid impact off the Yucatan peninsula. The
fossil record includes a layer of extra-terrestrial material,
churned up and distributed by the impact around the globe,
at exactly this time-period. More recently, the asteroid
impact of 1908 in Tunguska, Siberia flattened 2000 square
kilometers of forest with an impact energy 1,000 times that
of the Hiroshima atomic bomb.  Thus the potential for
disaster by an asteroid impact has already been demonstrated
in our planet's history. 
 
The threat of hazardous Near-Earth Objects has gained greater
attention in the public and press recently, in part as a
response to several close encounters with asteroids
discovered by the current national survey for such objects.
Currently NASA is surveying large NEOs with a goal of finding
and cataloging 90 percent of objects larger than one
kilometer by 2008.  Over 600 of these large objects have
already been found (Figure 2).  In addition to examining the
status and results of this survey and the NEO threat, this
hearing will explore the question of next steps beyond this
survey goal, including the costs, benefits, and technical
challenges of extending the survey to include smaller, yet
still potentially very hazardous, objects.  Agency roles,
interagency cooperation, and the possibilities for
international contributions to the NEO survey effort will
be discussed.
 
In particular, the important role of amateur astronomers
in the NEO survey and tracking effort will be highlighted.
Amateur astronomers are responsible for much of the
important tracking of NEOs after they are discovered.
Earlier this year, Rep. Dana Rohrabacher (R-CA) introduced
the "Pete Conrad" bill, H.R. 5303.  This bill would
establish awards for U.S. amateur astronomers who
contribute the most toward the discovery and tracking of
Near-Earth Asteroids. [See

[NOTE: Full text of the hearing charter is available at
http://www.house.gov/science/hearings/space02/oct03/charter.htm]


COMMITTEE ON SCIENCE
SUBCOMMITTEE ON SPACE AND AERONAUTICS
U.S. HOUSE OF REPRESENTATIVES
WASHINGTON, DC 20515

Hearing on

The Threat of Near-Earth Asteroids

Thursday, October 3, 2002
10:00 a.m. - 12:00 p.m.
2318 Rayburn House Office Building

WITNESS LIST

Dr. David Morrison
Senior Scientist
NASA Ames Research Center

[NOTE: Full text of statement is available at
http://www.house.gov/science/hearings/space02/oct03/morrison.htm]

Dr. Edward Weiler
Associate Administrator for Space Science
NASA Headquarters

[NOTE: Full text of statement is available at
http://www.house.gov/science/hearings/space02/oct03/weiler.htm]

Dr. Joseph Burns
Irving Porter Church Professor of Engineering and Professor of
  Astronomy
Cornell University

[NOTE: Full text of statement is available at
http://www.house.gov/science/hearings/space02/oct03/burns.htm]

Dr. Brian Marsden
Director, Minor Planet Center
Smithsonian Astrophysical Observatory

[NOTE: Full text of statement is available as PDF file (72KB) at
http://www.house.gov/science/hearings/space02/oct03/marsden.pdf]

Brigadier General Simon "Pete" Worden
Deputy Director for Operations
United States Strategic Command

[NOTE: Full text of statement is available at
http://www.house.gov/science/hearings/space02/oct03/worden.htm ]
Received on Thu 03 Oct 2002 09:49:51 PM PDT