The asteroid, known as 2011 MD, is among nine candidates on NASA’s
potential relocation list. Once an asteroid is robotically
repositioned about 46,600 miles (75,000 km) above the lunar surface,
NASA wants to send astronauts to visit it and collect samples. The
initiative is intended to test technologies and equipment needed for
an eventual human expedition to Mars.
Newly completed surveys with NASA’s infrared Spitzer space telescope
show 2011 MD is about 20 feet (6 meters) in diameter, roughly the
size of a delivery truck.
“You might actually be able to put this asteroid into your garage at
home,” astronomer David Trilling, with Northern Arizona University
in Flagstaff, told reporters on a conference call.
The asteroid, discovered in 2011, is about one-third as dense as
solid rock and has a mass of about 100 tons. Scientists suspect it
actually may be a pile of boulders, bound together by gravity and
other forces. Or, it could be one massive boulder surrounded by
smaller pebbles and dust. Either scenario is unexpected.
“Traditionally, people thought that small asteroids like 2011 MD are
just single pieces of rock or single boulders floating in space,”
said Trilling, who co-authored a study on 2011 MD published on
Thursday in The Astrophysical Journal Letters.
NASA has found about 11,000 asteroids that orbit near Earth and is
adding about 100 asteroids per month to the list. So far, nine
asteroids are believed to be suitably positioned for a robotic
rendezvous and capture between about 2020 and 2024.
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Another option is to pluck a boulder off a large asteroid and
reposition just that piece into the lunar orbit. Either initiative
is expected to cost about $1.25 billion, NASA said.
Also Thursday, NASA selected 18 asteroid mission concepts and
technology proposals for six-month study contracts totaling $4.9
million. Winning companies include aerospace giants Boeing and
Lockheed Martin, and startups, such as Deep Space Industries and
Planetary Resources Development Corp, both of which are developing
businesses to mine asteroids.
(Editing by Jonathan Oatis)
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