4 large asteroids, including a skyscraper-size 'city killer,' will zoom past Earth in a 12-hour span today (Oct. 24)

Four "potentially hazardous" space rocks, which are between 100 and 580 feet across, will all make their closest approaches to Earth within less than 12 hours of one another on Thursday (Oct. 24). Two of them were only discovered earlier this month.

An impressionist photo of 4 asteroids floating near Earth
Four large space rocks, between 100 and 580 feet across, will reach their closest points to Earth in quick succession on Thursday (Oct. 24).
(Image credit: Getty Images)

A quartet of particularly hefty asteroids, including two that were discovered earlier this month and another that is as tall as a skyscraper, will make their closest approaches to Earth on Thursday (Oct. 24) — all within 12 hours of one another. The "potentially hazardous" space rocks will all get similarly close to our planet, but pose zero threat to life on Earth.

The first asteroid to make its closest approach will be 2015 HM1, also the smallest of the four space rocks at around 100 feet (30 meters) across. It will reach its closest point to our planet at around 4:36 a.m. UTC (0:36 a.m. EDT) when it reaches a minimum distance of 3.4 million miles (5.5 million kilometers) from us, according to NASA's Asteroid Watch dashboard. (That’s roughly 14 times the average distance between Earth and the moon.)

Harry Baker
Senior Staff Writer

Harry is a U.K.-based senior staff writer at Live Science. He studied marine biology at the University of Exeter before training to become a journalist. He covers a wide range of topics including space exploration, planetary science, space weather, climate change, animal behavior and paleontology. His recent work on the solar maximum won "best space submission" at the 2024 Aerospace Media Awards and was shortlisted in the "top scoop" category at the NCTJ Awards for Excellence in 2023. He also writes Live Science's weekly Earth from space series.