City-killer' asteroid speeding to Earth as NASA reveals odds of it hitting the Moon go up

A "city-killer" asteroid has been found to have a greater chance of hitting the Moon than Earth. Space rock 2024 YR4 was detected last year, with an estimation it had a 3% chance of striking our planet on December 22, 2032.

Further observations saw the threat reduce to almost zero, but they now show the rock has a small chance of hitting the Moon. An observation collected by NASA's James Webb Space Telescope led to experts improving their knowledge of where the building-sized rock will be on December 22, 2032 by almost 20%.

NASA said the asteroid’s probability of hitting the Moon has risen slightly from 3.8% to 4.3%. However, the space agency said the "small chance" of the asteroid striking the Moon would not alter the orbit of Earth's only natural satellite.

Recent estimates show there is a 95% chance 2024 YR4 will miss the Moon.

An international team of experts led by Dr Andy Rivkin from Johns Hopkins Applied Physics Laboratory in the US made the observations using Webb’s Near-Infrared Camera in May.

Asteroid 2024 YR4 is now too far away to observe with space or ground-based telescopes.

NASA expects to make more observations when the space rock's orbit around the Sun brings it closer to Earth in 2028.

Infrared observations from the James Webb Space Telescope made in March estimate 2024 YR4 measures 174-220 feet (53-67m).

When it was first discovered by experts at the Minor Planet Centre, 2024 YR4 appeared to have a "very small" chance of hitting Earth.

But after more observations of the asteroid were added to calculations of its orbit, 2024 YR4 was deemed to have "no significant chance" of Earth impact in 2032 or beyond.

Recent analysis of 2024 YR4 suggests it might once have been a boulder on the surface of a larger asteroid. Astronomers found it was rich in silicates, according to the Independent.

This showed the asteroid is likely to have been pushed into its current orbit through gravitational interactions with Jupiter.