With a probability that has risen from 1.3% to 2.3% in just a few weeks, the threat posed by asteroid 2024 YR4 has caught the attention of the global scientific community. This football field-sized asteroid, estimated to be between 130 and 300 feet in diameter, could potentially strike Earth on December 22, 2032. This has elevated its status on the Sentry List—an inventory of objects that could impact Earth—making it a prime candidate for detailed study using the most advanced telescopes available.
James Webb Space Telescope Joins the Fray
Positioned at the Earth-Sun L2 Lagrange point, the James Webb Space Telescope (JWST) is uniquely equipped to observe and gather data on 2024 YR4. Utilizing its Mid-Infrared Instrument (MIRI), the telescope is scheduled to perform detailed observations that will enhance our understanding of the asteroid’s size, density, and composition. These observations are critical, as 2024 YR4’s exact dimensions and material makeup remain uncertain, factors that directly influence the potential severity of an impact.
“Webb will get data on the full spectrum from the end of the visible all the way to the infrared, in one go with one instrument, so it will be much cleaner and easier to interpret,” explained Oliver Hainaut from the European Southern Observatory, who has previously studied the asteroid using the Very Large Telescope in Chile. Hainaut’s findings have already ruled out the possibility of 2024 YR4 being a comet or primarily metallic in composition.
Precision Observations in a Narrow Window
The urgency of these observations is compounded by the asteroid’s current trajectory. 2024 YR4 is moving rapidly away from Earth and will soon be obscured by the sun’s glare, rendering it invisible to ground-based telescopes until June 2028. Webb’s intervention during this narrow window is crucial. The telescope will dedicate four hours of director’s discretionary time to study the asteroid, strategically placed between its regular scientific missions.
“The presence of a full moon and the asteroid’s increasing distance make each passing night critical,” said Hainaut, emphasizing the diminishing opportunities to observe the asteroid with ground-based telescopes.
Global Impact and Preparedness
Should 2024 YR4 impact Earth, its path could span across vital regions including the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, the Arabian Sea, and South Asia. This underscores the importance of international cooperation in monitoring near-Earth objects. The International Asteroid Warning Network (IAWN), chaired by NASA, plays a pivotal role in coordinating global efforts to prepare for potential asteroid impacts.