NASA issues alert: Eiffel Tower-sized asteroid to make 'close encounter' with Earth at 30,000 km/h this weekend

A colossal asteroid the size of a 100-storey building is barreling past Earth this weekend in a high-speed flyby that's captured the full attention of NASA's asteroid trackers. Named 387746 (2003 MH4), the space rock spans 335 metres and will zip past Earth at 4:07 PM IST on May 24, travelling at a blistering 30,060 km/h — fast enough to orbit the planet in just over an hour. NASA has classified the flyby as a “close encounter,” and though the asteroid poses no threat of collision, its immense size and speed have put scientists on alert.

Belonging to the Apollo group of asteroids — those with orbits that cross Earth’s path — 2003 MH4 will pass at a distance of 6.67 million kilometres, or about 17 times the Earth-Moon distance. That’s close enough to earn the "Potentially Hazardous Asteroid" tag, given its size exceeds 140 metres and it comes within the 7.5 million kilometre threshold.

The concern isn’t this flyby, but what future trajectories might hold. Even minor gravitational nudges from planets or subtle forces like the Yarkovsky effect, where sunlight slowly alters an asteroid’s path, could redirect such objects over time. “This weekend’s sighting is a warning, not a threat,” stated NASA’s Centre for Near-Earth Object Studies (CNEOS).

Just days earlier, on May 21, a smaller asteroid named 2025 KF made an even closer pass — just 111,000 kilometres from Earth, or less than a third of the distance to the Moon. Discovered only this year, the 23-metre-wide rock drew comparisons to a stack of twelve and a half gorillas in height, according to a whimsical WWF-based analogy.

Despite its size, 2025 KF is being treated seriously. Many space rocks are not solid but “rubble piles” — loose clusters of debris held together by gravity, which can shift or disintegrate under planetary influence. “If one of these rocks ever hit Earth, the destruction would be enormous,” experts warn. The impact could rival thousands of nuclear bombs, unleashing fires, tsunamis, and seismic shocks, followed by dust clouds that might block sunlight and trigger a so-called “impact winter.”

CNEOS and other observatories continue to scan the skies, not only to detect new threats early but also to develop strategies for deflecting or destroying them if needed. For now, this flyby is a cosmic near-miss — and a potent reminder that in space, safety is never guaranteed.