Astronomers will use the James Webb Space Telescope (JWST) to observe the potentially hazardous asteroid 2024 YR4. This will make it possible to determine the size of the celestial body, which in turn will make it possible to clarify the potential consequences of its fall.
2024 YR4 has become the first relatively large asteroid in many years, which has, albeit small, the probability of collision with the Earth. The hit could happen on December 22, 2032. Now its probability is estimated at 2.1%.
Although the chances of such an unfavorable scenario are very low, astronomers can’t ignore them. The problem is that in a few months the asteroid will disappear from the field of view of Earth’s telescopes. It is possible that a small probability of a collision will persist until 2024 YR4 comes close to Earth again in 2028 and astronomers have the opportunity to make additional observations.
Although a potential 2024 YR4 collision would not be a global catastrophe, it could have serious consequences at the local level. However, their estimation is hampered by the fact that astronomers do not know the size of the asteroid. Current estimates put its diameter at between 40 and 90 meters, and it hasn’t changed much since 2024 YR4 was first detected in December 2024.
The stumbling block is the albedo (degree of reflectivity) of the 2024 YR4. The asteroid may have a diameter of 40 meters but has a bright surface, making its visible size appear larger. Conversely, the 2024 YR4 may reflect almost no light, which will give the impression that it is smaller than it actually is. For obvious reasons, a 90-meter diameter asteroid hitting Earth would have much more noticeable consequences than a 40-meter asteroid impact.
Because of these difficulties, astronomers decided to engage JWST to better estimate the size of the asteroid. Its main advantage over ground-based telescopes is that JWST observes in the infrared. By recording the heat emitted by the asteroid’s surface, the space telescope will be able to determine its diameter much more accurately.
Under the current plan, the first round of observations will take place in early March, when the asteroid is brightest for JWST. The data collected by the telescope will be used by NASA and ESA to assess its hazard and determine potential responses. JWST is also expected to refine the orbital parameters of 2024 UR4, which will also help astronomers.
According to ESA
