🔗 2024YR4 Collision Chance is now 1.9%

🔗 Astronomy 🔗 Astronomy/Astronomical objects

2024 YR₄ is an asteroid between 40 and 90 metres (130 and 300 ft) in diameter, classified as an Apollo-type (Earth-crossing) near-Earth object. It was discovered by the Chilean station of the Asteroid Terrestrial-impact Last Alert System (ATLAS) on 27 December 2024. As of 5 February 2025, 2024 YR₄ was rated 3 on the Torino scale with a 1 in 53 (1.9%) chance of impacting Earth on 22 December 2032. NASA gives a Palermo Technical Impact Hazard Scale rating of −0.40 for 2024 YR₄, which corresponds to an impact hazard of 39.8% of the background hazard level. The discovery has triggered the first step in planetary defense responses, in which all available telescopes are asked to gather data about the object and United Nations-endorsed space agencies are prompted to begin planning for asteroid threat mitigation.

Preliminary analysis of spectra and photometric timeseries of this asteroid suggests it is a stony S-type or L-type asteroid with a rotation period near 19.5 minutes. The asteroid previously made a close approach of 828,800 kilometres (515,000 miles; 2.156 lunar distances) to Earth on 25 December 2024 (two days before its discovery), and is now moving away from Earth. It will make its next close approach around 17 December 2028. By early April 2025 and until June 2028, 2024 YR₄ will have moved too far away from Earth to be observed by ground-based telescopes. Space-based infrared telescopes such as the James Webb Space Telescope may be able to observe 2024 YR₄ when it is far from Earth.