NEW YORK: NASA has discovered an asteroid that traveled unusually close to the Earth orbited by a smaller asteroid moon.
The small natural satellite was spotted in radar images taken by NASA’s Deep Space Network antenna located in California. NASA released a GIF composed of 20 images showing the pair of space rocks.
At a distance of 745,000 miles, the asteroid’s approach was the closest it will get to Earth in at least the next two centuries, according to NASA’s Jet Propulsion Laboratory. It was also the nearest any rock of comparable size will get to the planet until 2027, when an asteroid called 1999 AN10 is expected to fly by.
The asteroid that just missed us, called 2004 BL86, is about 1,100 feet across. Its moon is about 230 feet across.
NASA has one of the most extensive programs in the world for surveying near-Earth objects (NEOs). The agency says 98% of the known NEOs were discovered by U.S. astronomers. Of the NEOs around the same size as BL86, about 16% have at least one moon in orbit around them; some even have two.
The space agency says it is constantly on the lookout to protect the planet from asteroids that might get dangerously close. Next year, it will send a robotic probe to one of the most potentially hazardous of the documented asteroids. That mission, OSIRIS-REx, is meant to serve as a dry run for spacecraft that might have to perform reconnaissance on NEOs that pose a threat in the future.
Besides the potential danger, comets and asteroids can also serve as a window into the origins of the solar system, water on Earth and maybe even the organic particles that eventually led to life, NASA says.
In the meantime, one question remained about the asteroid’s moon — and a famous former NASA astronaut was the one to pose it.