NASA’s James Webb Space Telescope (JWST) has conducted its first observations of the near-Earth asteroid 2024 YR4. This asteroid will get very close to the Moon and possibly risk an impact during its close approach in December 2032. On March 26, 2023, we performed the first evaluation. It showed that 2024 YR4 can be a lot bigger and more rocky than we had been estimating so far. Although Earth is now considered safe from impact, the Moon may still be in danger.
2024 YR4 is a known asteroid with well-established size and trajectory. According to present-day estimates, it’s about 200 feet (60 meters) across. This new measurement exceeds previous estimates of around 180 feet (55 meters). The asteroid’s trajectory frequently intersects Earth’s orbit around the Sun, raising concerns about possible collisions in the future.
Insights from JWST Observations
The JWST leveraged its state-of-the-art infrared sensors to pick up heat signals from 2024 YR4. This breakthrough allowed researchers to get important clues into the object’s size and composition. These discoveries suggested that the asteroid was more complicated in structure than had been thought. Perhaps most interestingly, during a five-hour period, it rotates once every 20 minutes, adding to the eccentricities that make it special.
The European Space Agency (ESA) has set aside emergency discretionary time for the JWST. This emergency action takes significant steps to understand the proposed size and trajectory of 2024 YR4. The observations you make will be key in helping us refine our prediction of the asteroid’s path. This will be especially important as it makes its closest approach to Earth and Moon in late 2032.
“In general, the brighter the asteroid, the larger it is, but this relationship strongly depends on how reflective the asteroid’s surface is,” – ESA officials.
Researchers have long warned that the ramifications of 2024 YR4’s size are dire. If the impact is more like 40m (130ft), it poses a much less serious threat. If it gets anywhere near 90 meters (295 feet), the danger jumps exponentially. This variability in size might have a tremendous impact on the potential impacts of a collision.
Potential Impact on Earth and the Moon
Scientists have verified there is no possibility of 2024 YR4 hitting Earth by December 22, 2032. There’s still a chance that the asteroid will end up hitting the Moon as it approaches, so hang tight. This scenario would provide scientists with a unique opportunity to study the formation of lunar craters caused by known asteroids.
“While an Earth impact by 2024 YR4 on December 22, 2032 has now been ruled out, it continues to have a non-zero probability of impacting the Moon at this time,” – researchers.
Alan Fitzsimmons, an astronomer who took part in the study, said it was “incredibly significant” that such an event had finally occurred.
“It would have no effect on Earth, but would allow us to study the formation of a lunar crater by a known asteroid for the very first time.” – Alan Fitzsimmons
This potential lunar impact would provide scientists with unique and priceless data. They’re equally excited to be learning about the history of our own Moon—nature’s time capsule—as well as the behavior of asteroids.
Future Observations Planned
A second round of follow-up observations with the JWST are planned for May 2025. This follow-on study aims to improve the orbital trajectory of 2024 YR4. Additionally, scientists hope to better predict in advance whether it will actually hit the Moon. As the approach date for this near-Earth object gets closer, scientists will be monitoring it more closely.
That continuing research is a strong reminder of why it is important to keep tracking near-Earth asteroids like 2024 YR4. As technology advances, telescopes like the JWST will play an increasingly critical role in understanding these celestial bodies and assessing any potential threats they may pose.
