Earth has 2.8 days to avert satellite disaster in solar storm
A new study warns that Earth’s increasingly crowded satellite network could descend into catastrophic collisions within just 2.8 days if operators lose control during a major solar storm or system failure, underscoring the mounting risks in low-Earth orbit.
The findings, published December 11 in a pre-print paper on arXiv by researchers led by Sarah Thiele of Princeton University, introduce the “CRASH Clock”—or Collision Realization and Significant Harm Clock—to measure how quickly disaster could unfold. The metric has plummeted from 121 days in 2018, before the megaconstellation era, highlighting the dramatic increase in orbital congestion.
“We were shocked it was that short,” Thiele told New Scientist.
The timing is particularly urgent following a near-miss last week between a Chinese spacecraft and a Starlink satellite, which passed within just 200 meters of each other on December 9. Michael Nicolls, vice president of Starlink engineering at SpaceX, said the incident underscored coordination failures between satellite operators.
Rising Collision Risks
Low-Earth orbit now hosts approximately 14,000 active satellites, a more than threefold increase since 2018, with SpaceX’s Starlink constellation comprising roughly 9,300 operational satellites. According to the study, satellites across all megaconstellations now pass within one kilometer of each other every 22 seconds.
Starlink satellites alone performed approximately 145,000 collision-avoidance maneuvers in the first six months of 2025, averaging about four maneuvers per satellite per month. The researchers found that even a 24-hour loss of control carries a 30 percent probability of triggering a catastrophic collision that could initiate Kessler syndrome—a cascading debris scenario that could render portions of orbit unusable.
Solar Storm Threat
The study identifies powerful solar storms as a primary threat, capable of disrupting satellite navigation and communication systems while increasing atmospheric drag. A Carrington-level event—similar to the 1859 solar storm that disrupted telegraph systems globally—could disable satellite control for over three days.
“The immense flow of energy ejected by the Sun may cause damage to all our satellites in orbit,” said Jorge Amaya, ESA’s space weather modeling coordinator, during recent simulations. “An explosion of the magnitude of the Carrington Event would leave no spacecraft safe.”
Hugh Lewis, a space debris expert at the University of Birmingham, told New Scientist that the CRASH Clock illustrates escalating orbital congestion. “Can we keep adding to that house of cards?” he questioned. “The more cards get added, the bigger the collapse is when things go wrong.”
The researchers hope the CRASH Clock will prompt immediate changes to satellite deployment and operation practices as tens of thousands more satellites are planned for launch by SpaceX, Amazon, and Chinese companies in coming years.