[meteorite-list] NASA Leonids Activities: Sleepyheads May Miss Spectacular Celestial Display

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:47:11 2004
Message-ID: <200111142131.NAA29326_at_zagami.jpl.nasa.gov>

Dolores Beasley
Headquarters, Washington, DC Nov. 14, 2001
Phone: 202/358-1753

RELEASE: 01-222

NASA LEONIDS ACTIVITIES: SLEEPYHEADS MAY MISS
SPECTACULAR CELESTIAL DISPLAY

     Early birds may catch more than their proverbial worms
this week. In the predawn hours of Sunday, Nov.18, the annual
Leonid meteor shower may put on one of its best shows in
decades, according to various scientists modeling the
expected Leonid activity this year.

"It's time to set your alarm clocks and get yourself out
under a dark sky," said Dr. Donald Yeomans, head of NASA's
Near Earth Object program office, at the Jet Propulsion
Laboratory, Pasadena, Calif. "This could be the last
opportunity for watching an impressive meteor storm in a dark
sky for decades to come."

Meteors, also called shooting stars, are really streaks of
light that flash across the sky as bits of dust and rock in
space collide with the Earth's upper atmosphere and vaporize.
The Leonid shower appears every year around Nov. 17 or 18 as
the Earth intersects the orbit of comet Tempel-Tuttle and
runs into streams of dust shed by the comet. Best viewing
times this year are predicted to be the early morning hours
of November 18, with the peak activity expected around 5 a.m.
EST.

They are called Leonid meteors for the direction in the sky
from which they appear to originate -- the constellation Leo.
Because the stream of comet dust hits the Earth almost head-
on, the Leonids are among the fastest meteors around -- they
zip silently across the sky at 44 miles per second. Every so
often, the Earth passes through an especially dense clump of
dust from Tempel-Tuttle, and a truly spectacular meteor storm
occurs -- the great Leonid storm of 1966 produced 150,000
meteors per hour.

Four NASA centers -- Marshall Space Flight Center,
Huntsville, Ala.; Goddard Space Flight Center, Greenbelt,
Md.; Ames Research Center, Moffett Field, Calif.; and the Jet
Propulsion Laboratory, Pasadena, Calif. -- have activities
scheduled around this year's meteor shower.

At Marshall, researchers will use special cameras to scan the
skies and report meteor activity around the clock Nov. 17 and
18. From six key points on the globe, they will record and
transmit their observations to Marshall's Leonid Environment
Operations Center, a data clearinghouse that will provide
meteor updates in near real-time through:
http://www.SpaceWeather.com -- a Web site sponsored by
science_at_nasa.gov.

"We're collecting this data to analyze and refine our meteor-
forecasting techniques," said Dr. Rob Suggs, the Leonid
Environment Operations Center team leader. "If we can better
determine where, when and how the meteors will strike, we can
take protective measures to prevent or minimize damage to our
spacecraft."

The researchers, along with colleagues from the University of
Western Ontario in Canada and the U.S. Air Force, will
monitor the storm from six locations, Huntsville, Ala.; Eglin
Air Force Base, Fla.; Maui, Hawaii; Sunspot, N.M.; the U.S.
Territory of Guam; and the Gobi Dessert in Mongolia. Each
location was selected based on meteor forecasts and the
area's climate.

The monitoring team also has the capability to detect meteors
the casual observer may miss. Using special image-intensified
cameras that can detect faint objects even in low-light
conditions, the researchers will monitor the shower, using
the video screens as windows to the skies. Every hour, the
teams will relay their observations to the Marshall control
center, helping to paint a comprehensive picture of the
meteor storm.

Most Leonid particles are the size of dust grains, and will
vaporize very high in the atmosphere, so they present no
threat to people on the ground or even in airplanes. However,
there is a slight chance that a satellite could be damaged if
it were hit by a Leonid meteor. The meteors are too small to
simply blow up a satellite. However, the Leonids are moving
so fast they vaporize on impact, forming a cloud of
electrified gas called plasma. Since plasma can carry an
electric current, there is a risk that a Leonid-generated
plasma cloud could cause a short circuit in a satellite,
damaging sensitive electronic components.

Goddard Space Flight Center is responsible for controlling
many satellites for NASA and other organizations and is
taking precautions to mitigate the risk posed by the Leonids.
These include pointing instrument apertures away from the
direction of the Leonid stream, closing the doors on
instruments where possible, turning down high voltages on
systems to prevent the risk of a short circuit, and
positioning satellites to minimize the cross-section exposed
to the Leonids.

Goddard controls or manages 21 satellites in the earth and
space sciences. It also manages NASA's Tracking and Data
Relay Satellite System constellation, which is controlled
from White Sands, N.M.

At Ames, meteor experts Dr. David Morrison, chief scientist
at NASA's Astrobiology Institute, and Dr. Scott Sanford, a
NASA planetary scientist, will be available Friday, Nov. 16,
at Ames for media interviews about the Leonid meteor storm.
The scientists will discuss NASA's airborne mission to study
the Leonids, the danger the meteors could pose to satellites,
recent Leonid prediction models and the latest research,
which suggests that meteors may have played a role in the
origin of life.
 
On Nov. 18, a team of 19 astrobiologists from five countries
will depart from southern California's Edwards Air Force Base
on an NKC-135 research aircraft to keep an eye on the sky for
satellite operators and to study the processes that may have
jump-started life on Earth. The 418th Flight Test Squadron at
Edwards Air Force Base operates the research aircraft, which
flew previous Leonid Multi-instrument Airborne Campaign (MAC)
missions in 1998 and 1999 over Japan and Europe.

Many scientists think meteors might have showered the Earth
with the molecules necessary for life's origin. "We are eager
to get another chance to find clues to the puzzling question
of 'What happens to the organic matter brought in by the
meteoroids?'" said Dr. Michael Meyer, lead scientist for
astrobiology at NASA Headquarters, Washington, which is
sponsoring the airborne observing mission.

Astrobiology is the study of the origin, evolution,
distribution and future of life in the universe. Ames is
NASA's lead center for astrobiology and the location of the
central offices of the NASA Astrobiology Institute, an
international research consortium.

Information about the Leonid Multi-instrument Airborne
Campaign (MAC) and live Leonid coverage are available at:

http://leonid.arc.nasa.gov/
or
http://www-space.arc.nasa.gov/~leonid/

Observers can calculate local meteor rates using their home
computers via:
http://www.space.arc.nasa.gov/~leonid/fluxestimator.html
The Jet Propulsion Laboratory (JPL) will host a webcast with
Yeomans explaining what the Leonids are and how to see them
on the JPL Web site at:
http://www.jpl.nasa.gov

NASA TV will broadcast live commentary and video of the
Leonids from 12:30 a.m. to 6 a.m. EST Sunday, Nov. 18. The
broadcast, originating from Marshall, will feature live video
of the Leonids meteor shower provided by a video camera with
enhanced images and animation. If weather and cloud cover
inhibit observation, the broadcast will be cancelled and
regular programming resumed.

NOTE TO EDITORS: More information on Leonids activities at
specific NASA Centers is available from:
Steve Roy, Marshall Space Flight Center, at: 256/544-6535;
Bill Steigerwald, Goddard Space Flight Center, at: 301/286-
5017; Kathleen Burton, Ames Research Center, at: 650/604-
1731;
Martha Heil, Jet Propulsion Laboratory, at: 818/354-0850.
                           -end-

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Received on Wed 14 Nov 2001 04:31:09 PM PST