Scientists from the National Aeronautics and Space Administration (NASA) have revealed that the mountain-sized asteroid that zipped by in close proximity to Earth on Monday has its own moon.
This new information about the asteroid known as 2004 BL86 was based on radar images that were released by researchers working at the 230-foot-wide Deep Space Network antenna at Goldstone, California.
Prior to the flyby, radar astronomer Lance Benner, principal investigator for the Goldstone radar observations of the asteroid said that detailed images of the 2004 BL86 will be revealed a day after the flyby. Scientists were anticipating for surprises because virtually nothing is known about the giant asteroid.
The new images showed the space rock, which made its closest approach to Earth at 11:19 a.m. EST on Jan. 26 at just a little over three times the distance from the Earth and the moon.
The 20 images used in a movie that was generated using data that were collected at Goldstone revealed that the space rock, which measured about 1,100 feet across has its own natural satellite. The small moon is estimated to measure about 230 feet across. The radar images have resolution of 13 feet per pixel.
The new findings about the giant asteroid suggest that it is somehow unique because only about 16 percent of asteroids measuring at least 200 meters are binary, which means the primary asteroid comes with a smaller asteroid moon that orbits around it, or are triple systems, which are marked by two moons.
Radar is used for studying the size, shape, rotation state, surface features and roughness of an asteroid. It is also used to improve the calculations of asteroid orbits. Radar measurements of asteroid velocities and distances allow scientists to compute asteroid orbit much farther into the future compared when radar observations are not used, allowing them to better estimate potential dangers posed by these extraterrestrial objects.
The U.S. space agency tracks asteroids in a bid to protect the Earth from them. NASA is using survey and detection programs to discover near-Earth objects (NEOs), which have so far found over 98 percent of currently known NEOs.
Although asteroid can pose threats to our planet, Don Yeomans, from NASA's Near Earth Object Program Office said that the asteroid 2004 BL86, which was detected by the Lincoln Near-Earth Asteroid Research (LINEAR) survey in Mexico in Jan. 30, 2004, does not pose threat to our planet in the foreseeable future.