A Russian KOSMOS 2499 satellite broke up last month—for a second time—according to the Space Force's 18th Space Defense Squadron. In a recent tweet, the Space Force said they are currently tracking 85 individual pieces of debris at an altitude of 1,169 km (726 miles). The breakup occurred on January 4, 2023, but the reason for the disintegration remains unknown.

At this high altitude, it will take decades for the debris to deorbit and burn up in the Earth's atmosphere. The debris is located in an increasingly busy region in Earth's orbit.

#18SDS has confirmed the breakup of COSMOS 2499 (#39765, 2014-028E)—occurred Jan 4, 2023 at appx 0357 UTC. Tracking 85 associated pieces at est 1169 km altitude—analysis ongoing. #spacedebris#space@SpaceTrackOrg@US_SpaceCom@ussfspoc

— 18th Space Defense Squadron (@18thSDS) February 7, 2023

But this is actually the second breakup event of Kosmos 2499.

Scientists and government agencies have been worried about the space junk surrounding Earth for decades. But humanity's starry ambitions are farther reaching than the space just around Earth. Ever since the 1960s with the launch of the Apollo program and the emergence of the space race between the U.S. and Soviet Union, people have been leaving trash around the moon, too.

Today, experts estimate that there are a few dozen pieces of space junk like spent rocket bodies, defunct satellites and mission-related debris orbiting in cislunar space—the space between Earth and the moon and the area around the moon. While this isn't yet a large amount of junk, astronomers have very little information about where these pieces of space debris are, let alone what they are and how they got there.