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Asteroid 2008 TC3 Strikes Earth: Predictions and Observations Agree
November 4, 2008
A spectacular fireball lit up the predawn sky above Northern Sudan on October 7, 2008. This explosion was caused by the atmospheric entry of a small near-Earth asteroid, estimated to be no more than a few meters in diameter. Although such small impact events occur several times per year around the globe, this case was unprecedented because the asteroid was actually discovered the day before it reached the Earth and the impact location and time were for the first time predicted in advance.
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Near-Earth Object (NEO) Analysis of Transponder Tracking and Gravity Tractor Performance
October 9, 2008
A study, requested and funded by the B612 Foundation, was
carried out by JPL scientists to detemine the feasibility of using a
gravity tractor concept for use in NEO impact mitigation and to build
credibility for the concept.
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Impact of Asteroid 2008 TC3 Confirmed
October 7, 2008
Confirmation has been received that the asteroid impact fireball
occurred at the predicted time and place. The energy recorded was
estimated to be 0.9
to 1.0 kT of TNT and the time of detection was 02:45:45 on October 7
(Greenwich Standard Time).
An additional confirmation was apparently reported by a KLM airliner
As reported by Peter Brown
(University of
Western Ontario, Canada), a preliminary examination of infrasound
stations nearest to the predicted impact point shows that at least
one station recorded
the event. These measurements are consistent with the predicted time
and place of the atmospheric impact and indicate an estimated energy
of 1.1 - 2.1 kT
of TNT.
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Small Asteroid Predicted to Cause Brilliant Fireball over Northern Sudan (2008 TC3)
October 6, 2008
A very small, few-meter sized asteroid, designated 2008 TC3, was
found Monday morning by the Catalina Sky Survey from their
observatory near Tucson Arizona. Preliminary orbital computations by
the Minor Planet Center suggested an atmospheric entry of this object
within a day of discovery. JPL confirmed that an atmospheric impact
will very likely occur during early morning twilight over northern
Sudan, north-eastern Africa, at 2:46 UT Tuesday morning.
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Near-Earth Object Testimony before the U.S. House of Representatives
Subcommittee on Space and Aeronautics
November 2007
On November 9, 2007, two NASA representatives and four outside
witnesses provided oral and written testimony to the House
Subcommittee and responded to several questions from Subcommittee
members. Most of the discussion centered upon the status of NASA's
ongoing near-Earth object search program, NASA's March 2007 Report to
Congress on the next generation search for so-called potentially
hazardous asteroids (PHAs) larger than 140 meters in diameter and the
utility of the Arecibo planetary radar in refining PHA orbits and
characterizing their physical natures. The NASA witnesses were Dr.
James Green (Director, Planetary Science Division, Science Mission
Directorate) and Dr. Scott Pace (Associate Administrator, Program
Analysis and Evaluation). The outside witnesses were Dr. Donald
Yeomans (Near-Earth Object Program Office manager at JPL), Dr. Don
Campbell (Professor of Astronomy, Cornell University), Dr. Anthony
Tyson (Professor of Physics at the University of California, Davis)
and Russell Schweickart (Chairman, B612 Foundation).
These testimonies can be accessed at:
http://www.science.house.gov/publications/hearings_markups_details.aspx?NewsID=2033
See also the NASA's March 2007 Report to Congress.
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Predicting Apophis' Earth Encounters in 2029 and 2036
October 2007
Researchers at NASA/JPL, Caltech, and Arecibo Observatory have released the results of radar observations of the potentially hazardous asteroid 99942 Apophis, along with an in-depth analysis of its motion. The research will affect how and when scientists measure, predict, or consider modifying the asteroid's motion. The paper has been accepted for publication in the science journal "Icarus" and was presented at the AAS/DPS conference in Orlando, Florida in October of 2007.
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