Study Says 13% of Earth Could Have Let 10-Km Asteroid Kill Dinosaurs

Q: An asteroid may hit the Moon in 2032. Could the debris shower trigger a catastrophic failure of Earth's satellites?

No. The specific 2032 case is no longer considered a threat: updated observations, including from the James Webb Space Telescope, have ruled out asteroid 2024 YR4 hitting the Moon. NASA now expects it to pass the Moon safely at about 21,200 kilometers. More broadly, a lunar impact can threaten satellites in principle, but a catastrophic collapse of Earth’s satellite network would be an extreme scenario, not the expected outcome. Researchers have warned that if a sufficiently large asteroid struck the Moon, the blast could eject lunar debris into space. Some fragments could cross Earth’s orbital region and hit satellites at very high speed. Because even small debris can disable spacecraft, this raises a real concern for satellite damage and, in the worst case, a debris cascade known as Kessler syndrome. That said, this remains a modeled, conditional risk rather than an established forecast. Whether a lunar impact would produce enough Earth-crossing debris to trigger widespread satellite failures depends on the asteroid’s size, speed, impact angle, and where it hits the Moon—much as Chicxulub research shows that impact consequences depend heavily on specific conditions, not just object size. So the practical answer is that the 2032 Moon-impact scenario has been ruled out, and even in a hypothetical future lunar strike, “catastrophic failure” of Earth’s satellites is possible in theory but not something scientists would assume without a much larger, well-characterized impact.

1 articles · Updated · spacedaily.com · May 27

A 2017 modeling study by Kunio Kaiho and Naga Oshima argues the Chicxulub asteroid caused mass extinction largely because it hit hydrocarbon-rich, sulphur-bearing seabed rather than most other terrains.
Their simulations put only about 13% of late-Cretaceous Earth in that high-risk category, with Chicxulub-like sediments generating enough stratospheric soot to cool the planet by roughly 8-11C and sharply cut rainfall.
Most other impact sites in the model produced only mild cooling, implying the asteroid’s location—not just its roughly 10-km size—may have been decisive in ending the dinosaurs’ reign.
The claim remains contested because the 13% figure is model-dependent, while other studies emphasize sulphate aerosols, fine silicate dust, or overlapping Deccan Traps volcanism as key drivers of the extinction.
A separate 2020 study also suggested Chicxulub was unusually destructive because the asteroid struck at about a 60-degree angle, reinforcing the idea that several features made it a worst-case impact.