March 10, 2026
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The NASA spacecraft is expected to re-enter the atmosphere with a chance of raining debris
Van Allen Probe A, which studied how our planet has been protected from harmful space radiation, could fall to Earth tonight. Here’s what you should know
An artist’s rendering represents NASA’s twin Van Allen Probes orbiting the Earth’s magnetic field to explore the radiation belts.
One of NASA’s spacecraft may re-enter the atmosphere at approximately 7:45 PM EDT tonight. The agency has warned that there is a one in 4,200 risk of human injury from potential debris.
When the 600-kilogram Van Allen Probe A re-enters Earth’s atmosphere, it will largely burn up, but there are some parts that NASA expects will survive the journey, the agency announced Monday. The exact time of the event is unclear: the space agency says the 7:45 p.m. EDT estimate has an uncertainty window of plus or minus 24 hours.
The spacecraft’s orbit is highly elliptical, so its exact “reentry time is still very uncertain,” says Jonathan McDowell, an astrophysicist who tracks satellites and space launches. “Based on the latest Space Force data, it may already be down, or it may not be down until late Wednesday night.”
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The probe is one of two sister spacecraft launched in 2012 to study the “Van Allen Belts” – bands of protons and electrons that hold Earth together and protect our planet from harmful space weather and radiation. The mission ended in 2019 when the probes ran out of fuel.
The Van Allen Belts are a harsh region and can be harmful to both spacecraft and astronauts. Remarkably, the probe was not expected to return to Earth until 2034, NASA said, but due to a “far more active than expected” solar cycle, it is coming down ahead of schedule.
It’s unclear from NASA’s memo where Probe A will enter the atmosphere — or where any debris might fall; both NASA and the US Space Force follow the path. (NASA did not immediately respond to a request for comment from Scientific American.) But the agency stressed that the risk of any danger to humans is “low,” or about one in 4,200. Most of Earth’s surface is covered in water, so parts of the probe are most likely to hit the ocean—minimizing the risk to humans. For context, however, the one-in-4,200 risk of danger to someone is higher than the odds of a single person being struck by lightning in their lifetime or of a diver or surfer being bitten by a shark.
The probes have served scientists well during their time in orbit: they helped discover an entire radiation belt previously unknown to scientists.
“The Van Allen probes rewrote the textbook on radiation belt physics,” Sasha Ukhorskiy, a project scientist at the Johns Hopkins Applied Physics Laboratory who worked on the mission, said in a 2019 statement when the probes retired. “The spacecraft used unique instruments to reveal radiation belt features that were nearly invisible to previous sensors, and discovered many new physical mechanisms for radiation belt acceleration and loss.”
Editor’s Note (3/10/26): This is a news item and may be updated.
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