Asteroids: NASA Tracking House-Sized Space Rock Near Earth

NASA has been tracking a house-sized asteroid in the vicinity of Earth that is hurtling through space at a zippy 42,300 miles per hour.

Known as “2025 HM4,” the asteroid’s path brought it within a cosmically-small 477,000 miles of our home, according to NASA’s Jet Propulsion Laboratory (JPL).

The space rock is estimated to be around 49 to 111 feet in diameter, according to the JPL’s Center for Near-Earth Object Studies (CNEOS).

Asteroids are small, rocky masses left over from the formation of the solar system around 4.6 billion years ago. They’re found in the main asteroid belt, orbiting around the sun between the paths of Mars and Jupiter.

2025 HM4 isn’t the only space rock approaching the Earth this week. NASA is also tracking two airplane-sized asteroids—the “2024 BF” and “2025 GT1”), spanning around 110 to 140 feet in diameter—that will zoom past our planet on Thursday at a distance of around 2.2 to 2.6 million miles from the Earth.

Another house-sized space rock—the “2025 HJ5,” which measures around 48 feet—will also be going past at about 2.5 million miles from the Earth on Friday.

Earlier this year in February, updated data from the CNEOS showed the Earth impact probability of the asteroid known as “2024 YR4” in 2032 was at 3.1 percent, which was “the highest impact probability NASA has ever recorded for an object of this size or larger,” NASA noted at the time.

Further studies on the asteroid’s trajectory later that month brought the chance of Earth impact on December 22 in 2032 down to 0.004 percent.

The space agency said that “NASA has significantly lowered the risk of near-Earth asteroid 2024 YR4 as an impact threat to Earth for the foreseeable future” and “the range of possible locations the asteroid could be on Dec. 22, 2032, has moved farther away from the Earth.”

Earlier this month, the 2024 YR4 was estimated to be about 200 feet by NASA’s James Webb Space Telescope. “That’s just about the height of a 15-story building,” noted Andy Rivkin, an astronomer at Johns Hopkins University who is the principal investigator of the Webb Director’s Discretionary Time program used to study 2024 YR4,

“All together, we have a better sense of what this building-sized asteroid is like. This in turn gives us a window to understand what other objects the size of 2024 YR4 are like, including the next one that might be heading our way,” Rivkin said in a NASA blog post on April 2.

The orbits of asteroids bring them within around 120 million miles of the sun. “The majority of near-Earth objects have orbits that don’t bring them very close to Earth, and therefore pose no risk of impact,” NASA notes.

A small portion of them, however, known as potentially hazardous asteroids (PHAs), do merit closer tracking. PHAs, which are around 460 feet in size, have orbits that bring them as close as within 4.6 million miles of the Earth’s orbit around the sun, NASA notes.

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