What Happens Once We Spot the Asteroid That Will Hit Earth?

Imagine getting an email with the subject line “Potential Asteroid Impact Notification.” That’s exactly what happened to someone in the U.S. Space Force this January, when, for the first time time ever, the international alert system for defending the planet against space rocks was activated. Scientists had identified the most dangerous near-Earth object ever recorded, an asteroid dubbed 2024 YR4. There was a 3 percent chance it would strike Earth in about eight years. Spoiler: The threat has since gone down to basically zero. Still, 2024 YRS inspired writer Tomas Weber to get to know the network of people whose job is planetary defense, and the long odds they’re up against should a rock actually come barreling toward Earth:

Some planetary-defense officials and astronomers, instilled with strains of space-age idealism, hope the news of an Earth-threatening inbound asteroid or comet might spur humanity to unite to protect ourselves. But when it comes to asteroids roughly the size of 2024 YR4, too small to threaten humanity as a whole but powerful enough to incinerate a city, the truth may be somewhat bleaker. The nature of the response is more likely to depend on where, exactly, the asteroid is set to fall—whether it’s headed, say, for the Panama Canal, as in the case of 2024 YR’s projected impact corridor, or for a medium-sized town in, say, Venezuela. 

The U.S., as the only nation with the demonstrated capacity to nudge near-Earth objects off a collision course, is the de facto world leader in planetary defense. It has a planetary defense action plan and employs a full-time planetary defense officer. But it is not clear whether the country would be a reliable protector of the Earth. 

In January, as 2024 YR4’s risk of impact was rising, the U.S. withdrew a second time from the Paris Agreement on climate change. It then cut ties, again, with the World Health Organization. The following month, the Department of Government Efficiency dismantled USAID—a move that one study estimates has already led to the deaths of nearly 300,000 people. Then, in May, the White House released a spending blueprint proposing to gut NASA’s science work, of which planetary defense is part, by nearly 50 per cent, a decision the administration said was necessary to focus “on beating China back to the moon.” The White House suggested shrinking funding for near-Earth object detection in particular by $3 million, a cut of nearly 8 percent. A NASA spokesperson told me the agency “remains dedicated to our mission of safeguarding our planet.” But if an asteroid were bearing down on Bangladesh, it seemed fair to ask, would the U.S. intervene—and would it demand anything in return? Would it for Iran?