[meteorite-list] PSI Scientists Study Surface Composition of Asteroid 2004 BL86 During Close Flyby of Earth

[Ron Baalke]

http://www.psi.edu/news/ceresopnav2

PSI Scientists Study Surface Composition of Asteroid 2004 BL86 During 
Close Flyby of Earth
Planetary Science Institute
Jan. 27, 2015
 
Tucson, Ariz. -- Planetary Science Institute researchers Vishnu Reddy 
and Driss Takir studied the surface composition of near-Earth asteroid 
2004 BL86 during its close flyby of Earth early this morning. 
 
Remotely operating the NASA Infrared Telescope Facility (NASA IRTF) on 
Mauna Kea, Hawaii, Reddy and Takir studied infrared sunlight reflected 
off the asteroid to determine its composition. They were part of a team 
of astronomers from around the world studying this object.
 
"Our observations show that this asteroid has a spectrum similar to V-type 
asteroids," said Reddy. "V-type asteroids are basalt, similar in composition 
to lava flows we see in Hawaii. The principal source of V-type asteroids 
is thought to be ancient basin-forming impacts on the south pole of the 
large, main-belt asteroid (4) Vesta. These impacts gave rise to the Vesta 
asteroid family spanning the inner part of the main asteroid belt, and 
some of those fragments in turn were transported to Earth-crossing orbits."

Vesta was the first target of NASA Dawn mission.
 
Photometric and radar observations by other astronomers also showed that 
2004 BL86 is a binary asteroid, a system where two asteroids orbit their 
common center of mass. 2004 BL86 is a 300-meter diameter asteroid that 
made a close flyby of the Earth on Monday morning at a distance of 745,000 
miles. It is the closest flyby of a large asteroid for the next 200 years. 

The research was funded by NASA's Near-Earth Object Observations Program 
through NASA Headquarters in Washington, D.C.