The potential threat posed by asteroid 2024 YR4 has significantly heightened, with the likelihood of it colliding with the Moon during the Christmas season of 2032 now more than double its previous estimates. Initially making headlines in February as the most perilous object in the Solar System concerning Earth, subsequent observations have dramatically reduced the risk of it striking our planet to just 0.004 percent. In a recent update, scientists have calculated that there is now nearly a one-in-25 chance of 2024 YR4 impacting Earth's only natural satellite.
Experts from NASA’s Center for Near Earth Object Studies, located at the agency’s Jet Propulsion Laboratory, have revised the probability of asteroid 2024 YR4 hitting the Moon on December 22, 2032. The chances have increased from 1.7 percent reported in late February to 3.8 percent, as announced by NASA this week. However, there remains a robust 96.2 percent chance that the asteroid will pass by without incident. In the unlikely event of a collision, it is important to note that the impact would not alter the Moon’s orbit.
Astronomers first detected asteroid 2024 YR4 using an automatic telescope on Christmas Day last year. Shortly thereafter, scientists assessed its potential trajectory and determined that it could potentially collide with Earth. After further analysis of its orbit, NASA began to consider the possibility of a lunar impact, initially estimating the risk at a mere 0.3 percent.
To investigate the physical properties of 2024 YR4, NASA has employed the advanced capabilities of the James Webb Space Telescope (JWST), utilizing its Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI). Initial results reveal that this asteroid is somewhat atypical compared to larger asteroids. The JWST team reported that the thermal properties of 2024 YR4—specifically how rapidly it heats up and cools down—do not align with those of larger celestial bodies. This anomaly is likely due to its rapid spinning motion and the absence of fine-grained sand on its surface. Preliminary estimates suggest that the asteroid is composed primarily of larger rocks, possibly fist-sized or bigger, and measures approximately 60 meters (200 feet) in diameter.
What would occur if a rock of this size were to collide with the Moon? According to NASA, the event would likely result in the formation of a small crater, although nothing on the scale of the Moon's largest impact feature, the South Pole-Aitken basin. By 2032, there might be a permanent human presence on the Moon, as both the United States, Russia, and China plan to establish bases there, with the European Space Agency (ESA) also exploring similar possibilities. Even if 2024 YR4 were to strike the Moon, the risk to human safety would be exceedingly low, providing a hopeful outlook for future lunar endeavors.
