JWST Observations of Potentially Hazardous Asteroid 2024 YR4

Rivkin, A. S.; Mueller, T.; MacLennan, E.; Holler, B.; Burdanov, A.; de Wit, J.; Pravec, P.; Micheli, M.; Devogele, M.; Conversi, L.; Thomas, C. A.; Farnocchia, D.; Dotson, J. L.; Wheeler, L.; Hammel, H.; Milam, S. N.; de Leon, J.; Glantzberg, A.
Bibliographical reference

Research Notes of the American Astronomical Society

Advertised on:
4
2025
Number of authors
18
IAC number of authors
2
Citations
0
Refereed citations
0
Description
The destructive power of an impacting asteroid is primarily estimated by knowledge of its size. Asteroid 2024 YR4 reached a peak 2032 impact probability with Earth of 3%, motivating a desire to determine its size. Owing to its infrared capabilities, JWST is uniquely suited for such assessment, especially for decameter-scale objects. We used JWST to observe 2024 YR4 and find a diameter of 60 ± 7 m. This size range corresponds to an albedo for 2024 YR4 of 8%–18%, consistent with observation that it is an S-type asteroid (International Asteroid Warning Network, https://iawn.net/obscamp/2024YR4/index.shtml), if at the low-albedo end of that asteroid taxon. Future observations through 2025 May will help further refine the asteroid's thermophysical model.