[meteorite-list] Arecibo Telescope Tracks 'Potentially Dangerous' Asteroid (2005 YU55)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 30 Apr 2010 15:58:32 -0700 (PDT)
Message-ID: <201004302258.o3UMwWX7016773_at_zagami.jpl.nasa.gov>

http://www.news.cornell.edu/stories/April10/AreciboAsteroid.html

Chronicle Online e-News

Arecibo telescope tracks 'potentially dangerous' asteroid within 1.5
million miles of Earth

April 30, 2010

By Blaine Friedlander Jr.
bpf2 at cornell.edu

A near-Earth asteroid named 2005 YU55 -- on the list of potentially
dangerous asteroids -- was observed by the Arecibo telescope April 19
as it passed about 1.5 million miles from the Earth (about six times
the distance to the moon).

The Arecibo Observatory, located in Puerto Rico, is part of the
National Astronomy and Ionosphere Center, managed by Cornell on
behalf of the National Science Foundation.

Arecibo radar imaging of 2005 YU55 showed that the asteroid is about
1,300 feet (400 meters) in size -- about a quarter-mile long -- and
twice as large as previously estimated.

As they tracked the asteroid, Cornell researcher Ellen Howell and
colleagues, including Cornell researcher Patrick Taylor, used
high-precision radar to reduce uncertainties about its orbit by 50
percent. This improvement eliminated any possibility of an impact
with the Earth for the next 100 years, and the asteroid was removed
from the "Risk Page" maintained by NASA's Near-Earth Object Program
Office at the Jet Propulsion Laboratory.

After circling the sun, 2005 YU55 will next approach the Earth to
about 0.8 lunar distances Nov. 8, 2011. It will pose no impact hazard.

  Robert McMillan of the Spacewatch asteroid detection program
discovered the asteroid on Dec. 28, 2005. President Barack Obama has
proposed that NASA's "Near Earth Object Observations" program budget
be increased to $20.3 million in 2011 from $3.7 million in 2009. NASA
has indicated that it intends to provide support to the Arecibo radar
program if that funding remains in the budget. Rep. Jose Serrano,
D-N.Y., added $2 million to NASA's near-Earth object research program
in 2010 for support of the Arecibo research work. These funds will
offset reduced funding from the National Science Foundation.

--------------------------------------------------

http://www.jpl.nasa.gov/news/news.cfm?release=2010-144

Radar Clicks Asteroid's Pic
Jet Propulsion Laboratory
April 29, 2010

Near-Earth asteroid 2005 YU55 was "imaged" by the Arecibo Radar
Telescope in Puerto Rico on April 19. Data collected during Arecibo's
observation of 2005 YU55 allowed the Near-Earth Object Program Office at
NASA's Jet Propulsion Laboratory to refine the space rock's orbit,
allowing scientists to rule out any possibility of an Earth impact for
the next 100 years.

The space rock was about 2.3 million kilometers (1.5 million miles) from
Earth at the time this image of the radar echo was generated. The
ghostly image has a resolution of 7.5 meters (25 feet) per pixel. It
reveals 2005 YU55 as a spherical object about 400 meters (1,300 feet) in
size.

Not only can the radar provide data on an asteroid's dimensions, but
also on its exact location in space. Using Arecibo's high-precision
radar astrometry capability, scientists were able to reduce orbit
uncertainties for YU55 by 50 percent.

"At one time we had classified 2005 YU55 as a potential threat," said
Steve Chesley, a scientist at JPL's Near-Earth Object Program Office.
Prior to the Arecibo radar passes on April 19 thru 21, we had eliminated
almost all upcoming Earth flybys as possibilities of impact. But there
were a few that had a low remaining probability of impact. After
incorporating the data from Arecibo, we were able to rule impacts out
entirely for the next 100 years."

With more observations in the coming years, scientists may be able to
accurately plot 2005 YU55's orbit even further out.

NASA detects, tracks and characterizes asteroids and comets passing
close to Earth using both ground- and space-based telescopes. The
Near-Earth Object Observations Program, commonly called "Spaceguard,"
discovers these objects, characterizes a subset of them, and plots their
orbits to determine if any could be potentially hazardous to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science
Mission Directorate in Washington. JPL is a division of the California
Institute of Technology in Pasadena.

More information about asteroids and near-Earth objects is at:
http://www.jpl.nasa.gov/asteroidwatch.

D.C. Agle 818-393-9011
Jet Propulsion Laboratory
agle at jpl.nasa.gov

2010-144
Received on Fri 30 Apr 2010 06:58:32 PM PDT