Mysterious Russian satellite breaks up in orbit, generating cloud of debris

A mysterious Russian satellite broke apart early last month, creating a cloud of debris that could linger in Earth orbit for a while.

The Kosmos 2499 spacecraft disintegrated on the night of Jan. 3, according to the U.S. Space Force‘s 18th Space Defense Squadron (18th SDS), which tracks human-made objects in orbit.

The breakup event generated at least 85 pieces of trackable debris, 18th SDS said via Twitter on Monday (Feb. 6). That cloud of space junk is orbiting 726 miles (1,169 kilometers) above Earth — so high that it’ll likely take a century or more for atmosphere drag to bring it down.

The 18th SDS did not speculate about the cause of the breakup. And that’s far from the only mystery surrounding Kosmos 2499.