A stadium-sized asteroid fell harmlessly to Earth this month as a powerful NASA radar system watched.
Asteroid 2008 OS7 passed Earth on February 2, 2024 at a safe distance of 1.8 million miles (2.9 million kilometers), 7.5 times the Earth-Moon distance. Although the space rock poses no threat to harm our planet, scientists at NASA's Jet Propulsion Laboratory (JPL) used the state-of-the-art Goldstone Solar System Radar (GSSR) to produce a series of images of the asteroid as it passed us.
The new observations helped narrow down the asteroid's size because most planetary radar systems were too far away to image it sufficiently until it got closer this month.
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Asteroid 2008 OS7 orbits the Sun every 2.6 years, passing through the orbit of Venus, which is closest to the Sun, and Mars, which is farthest away. 2008 OS7 is listed as „potentially hazardous” because of its size and how close it will pass to Earth, but JBL wrote that it won't come close to our planet for another 200 years. Report About these new observations.
While searching for near-Earth objects (NEOs) in 2008, scientists estimated 2008 OS7 to be between 650 and 1,640 feet (200 and 500 meters) across.
Using JPL's radar observations on February 2, scientists found the asteroid to be significantly smaller than those initial estimates; It is now believed to be 500 to 650 feet (150 to 200 meters) across. The new observations show that 2008 OS7 rotates at an unusually slow rate, completing one full rotation every 29.5 hours.
The Goldstone Solar System Radar's TSS-14 antenna is the world's only fully steerable planetary radar system. According to JPL. It is a 230-foot (70 m) antenna dish housed at the Goldstone Deep Space Communications Complex in California's Mojave Desert and is used to monitor space debris, solar system bodies, and near-Earth asteroids such as 2008 OS7.