Asteroid That Flew Past Earth Today Has Moon
Scientists working with NASA's 230-foot-wide (70-meter) Deep Space
Network antenna at Goldstone, California, have released the first radar
images of asteroid 2004 BL86. The images show the asteroid, which made
its closest approach today (Jan. 26, 2015) at 8:19 a.m. PST (11:19 a.m.
EST) at a distance of about 745,000 miles (1.2 million kilometers, or
3.1 times the distance from Earth to the moon), has its own small moon.
The 20 individual images used in the movie were generated from data
collected at Goldstone on Jan. 26, 2015. They show the primary body is
approximately 1,100 feet (325 meters) across and has a small moon
approximately 230 feet (70 meters) across. In the near-Earth population,
about 16 percent of asteroids that are about 655 feet (200 meters) or
larger are a binary (the primary asteroid with a smaller asteroid moon
orbiting it) or even triple systems (two moons). The resolution on the
radar images is 13 feet (4 meters) per pixel.
The trajectory of asteroid 2004 BL86 is well understood. Monday's
flyby was the closest approach the asteroid will make to Earth for at
least the next two centuries. It is also the closest a known asteroid
this size will come to Earth until asteroid 1999 AN10 flies past our
planet in 2027.
Asteroid 2004 BL86 was discovered on Jan. 30, 2004, by the Lincoln
Near-Earth Asteroid Research (LINEAR) survey in White Sands, New Mexico.
Radar is a powerful technique for studying an asteroid's size, shape,
rotation state, 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 if radar observations weren't
available.
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 over 98 percent of
the 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.
NASA's Near-Earth Object Program at NASA Headquarters, Washington,
manages and funds the search, study and monitoring of asteroids and
comets whose orbits periodically bring them close to Earth. 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.
In 2016, NASA will launch a robotic probe to one of the most
potentially hazardous of the known NEOs. The OSIRIS-REx mission to
asteroid (101955) Bennu will be a pathfinder for future spacecraft
designed to perform reconnaissance on any newly discovered threatening
objects. Aside from monitoring potential threats, the study of asteroids
and comets enables a valuable opportunity to learn more about the
origins of our solar system, the source of water on Earth, and even the
origin of organic molecules that led to the development of life.
NASA's Goddard Space Flight Center in Greenbelt, Maryland, will
provide overall mission management, systems engineering, and safety and
mission assurance for OSIRIS-REx. Lockheed Martin Space Systems in
Denver will build the spacecraft. OSIRIS-REx is the third mission in
NASA's New Frontiers Program. NASA's Marshall Space Flight Center in
Huntsville, Alabama, manages New Frontiers for the agency's Science
Mission Directorate in Washington.
NASA also continues to advance the journey to Mars through progress on the Asteroid Redirect Mission (ARM), which will
test a number of new capabilities needed for future human expeditions
to deep space, including to Mars. This includes advanced Solar Electric
Propulsion -- an efficient way to move heavy cargo using solar
power, which could help pre-position cargo for future human missions to
the Red Planet. As part of ARM, a robotic spacecraft will rendezvous
with a near-Earth asteroid and redirect an asteroid mass to a stable
orbit around the moon. Astronauts will explore the asteroid mass in the
2020’s, helping test modern spaceflight capabilities like new spacesuits
and sample return techniques. Astronauts at NASA's Johnson Space Center
in Houston have already begun to practice the capabilities needed for
the mission.
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