Scientists spot 10,000th medium near-Earth asteroid in planetary defense milestone

Scientists watching the skies for asteroids that may threaten Earth have hit a new milestone, spotting the 10,000th sizable space rock that circles the sun near Earth’s orbit.

The detection comes as part of NASA’s ongoing planetary defense work, which discovers and monitors space rocks in the inner solar system to assure that no large asteroid is on course to impact Earth. (To date, scientists don’t know of any space rocks that pose a serious threat to Earth in the near future.)