[meteorite-list] Radar Images Provide New Details on Halloween Asteroid (2015 TB145)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 3 Nov 2015 14:11:10 -0800 (PST)
Message-ID: <201511032211.tA3MBAVu028913_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?feature=4763

Radar Images Provide New Details on Halloween Asteroid
Jet Propulsion Laboratory
November 3, 2015

[Images]
Asteroid 2015 TB145 is depicted in eight individual radar images collected
on Oct. 31, 2015 between 5:55 a.m. PDT (8:55 a.m. EDT) and 6:08 a.m. PDT
(9:08 a.m. EDT).
Image Credit: NASA/JPL-Caltech/GSSR/NRAO/AUI/NSF

The highest-resolution radar images of asteroid 2015 TB145's safe flyby
of Earth have been processed. NASA scientists used giant, Earth-based
radio telescopes to bounce radar signals off the asteroid as it flew past
Earth on Oct. 31 at 10 a.m. PDT (1 p.m. EDT) at about 1.3 lunar distances
(300,000 miles, or 480,000 kilometers) from Earth. Asteroid 2015 TB145
is spherical in shape and approximately 2,000 feet (600 meters) in diameter.

"The radar images of asteroid 2015 TB145 show portions of the surface
not seen previously and reveal pronounced concavities, bright spots that
might be boulders, and other complex features that could be ridges," said
Lance Benner of NASA's Jet Propulsion Laboratory in Pasadena, California,
who leads NASA's asteroid radar research program. "The images look distinctly
different from the Arecibo radar images obtained on Oct. 30 and are probably
the result of seeing the asteroid from a different perspective in its
three-hour rotation period."

Radar images of asteroid 2015 TB145 acquired by Arecibo Observatory are
available at these sites:

http://on.fb.me/1MahsY8

https://twitter.com/AreciboRadar/status/661293813713928192

To obtain these highest-resolution radar images of the asteroid, scientists
used the 230-foot (70-meter) DSS-14 antenna at Goldstone, California,
to transmit high-power microwaves toward the asteroid. The signal bounced
off the asteroid, and its radar echoes were received by the National Radio
Astronomy Observatory's 100-meter (330-foot) Green Bank Telescope in West
Virginia. The radar images achieve a spatial resolution as fine as 13
feet (4 meters) per pixel.

The next time that asteroid 2015 TB145 will be in Earth's neighborhood
will be in September 2018, when it will make a distant pass at about 24
million miles (38 million kilometers), or about a quarter the distance
between Earth and the sun.

Radar is a powerful technique for studying an asteroid's size, shape,
rotation, surface features and surface roughness, and for improving the
calculation of asteroid orbits. Radar measurements of asteroid distances
and velocities often enable computation of asteroid orbits much further
into the future than would be possible otherwise.

NASA places a high priority on tracking asteroids and protecting our home
planet from them. In fact, the U.S. has the most robust and productive
survey and detection program for discovering near-Earth objects (NEOs).
To date, U.S. assets have discovered about 98 percent of known NEOs.

In addition to the resources NASA puts into understanding asteroids, it
also partners with other U.S. government agencies, university-based astronomers,
and space science institutes across the country, often with grants, interagency
transfers and other contracts from NASA, and also with international space
agencies and institutions that are working to track and better understand
these objects. In addition, NASA values the work of numerous highly skilled
amateur astronomers, whose accurate observational data helps improve asteroid
orbits after they are found.

JPL hosts the Center for Near-Earth Object Studies for NASA's Near-Earth
Object Observations Program within the agency's Science Mission Directorate.

More information about asteroids and near-Earth objects is at these sites:

http://neo.jpl.nasa.gov

http://www.jpl.nasa.gov/asteroidwatch


Media Contact

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle at jpl.nasa.gov

Charles Blue
National Radio Astronomy Observatory
434.296.0314
cblue at nrao.edu

2015-341
Received on Tue 03 Nov 2015 05:11:10 PM PST