Earth-orbiting satellites might start hitting one another in less than 3 days in a worst-case-scenario circumstance– possibly setting off a runaway waterfall that might render low Earth orbit (LEO)unusable, a brand-new preprint research study alerts. This is 125 days quicker than if an emergency situation had actually occurred simply 7 years earlier, according to the scientists’ freshly designed “CRASH Clock.”

The variety of spacecraft orbiting our world is increasing quick, thanks mainly to the increase of satellite “megaconsetllations,” such as SpaceX‘s Starlink network. Since May 2025, there were a minimum of 11,700 active satellites around Earth, the majority of which lie in LEO– the area of the environment as much as 1,200 miles (2,000 km) above Earth. For context, that is a 485% boost on the approximately 2,000 satellites in LEO at the end of 2018, before the very first Starlink launch in 2019. And all indications recommend that this is just the starting

In a brand-new research study, published to the preprint server arXiv on Dec. 10, scientists proposed a brand-new method of determining the threat of an accident taking place if every spacecraft was rendered unusable by among these worst-case circumstances. The group called this metric the Collision Realization And Significant Harm (CRASH) Clock. By designing the circulation of spacecraft in LEO, the CRASH Clock demonstrates how long it would consider the very first accident to happen. (This resembles how the notorious “Doomsday Clock” programs us how far we are far from a theoretical international armageddon.)

“The CRASH Clock is a statistical measure of the timescale expected for a close approach that could give rise to a collision,” research study co-author Aaron Boleyan astronomer at The University of British Columbia, informed Live Science in an e-mail. “The idea is that it can be used as an environmental indicator that helps to evaluate the overall health of the orbital region while enabling people to conceptualize just how much or how little room there is for error.”

The variety of satellites

orbiting Earth has actually more than quadrupled in the last 7 years, making crashes a lot more most likely if these spacecraft unexpectedly lost their avoidance abilities.

(Image credit: Getty Images)In the brand-new paper, the group computed that the worth of the CRASH Clock by the end of 2025 was around 2.8 days, with a 30% opportunity that an accident might take place within 24 hours of an emergency situation that renders satellites unusable. This is much less than the clock’s forecasted worth for 2018, approximated to be 128 days, which would have provided operators far more time to recuperate their properties.

These findings have actually not yet been peer-reviewed, and the research study group now believes that they a little overstated how brief the CRASH Clock truly is, Boley informed Live Science. The rate at which these timeframes have actually altered, regardless of their precise worths, is what is most worrying. (A brand-new, more dependable worth for the CRASH Clock is most likely to be released later on this year.)