Could Asteroid 2024 YR4 Collide with the Moon? Astronomers Explain Possible Effects on the Moon and Earth.

An asteroid the size of a building nearly collided with Earth… and now it could crash into the Moon. What did the James Webb Telescope discover?

Asteroid 2024 YR4, in an image from January 27. NASA/New Mexico Institute of Mining and Technology.

On December 27, 2024, a new asteroid was detected by the ATLAS system in Chile. Named 2024 YR4, this rocky object just 60 meters in diameter immediately caught the attention of astronomers for an unsettling reason: its potential trajectory toward Earth.

Initial orbital estimates indicated a 3.1% chance of collision on December 22, 2032. Although numerically low, that probability was serious enough to warrant close attention, especially considering the destructive potential of a body that size if it were to strike a populated area.

An asteroid 60 meters wide, while small by astronomical standards, could release energy equivalent to dozens of nuclear bombs if it entered Earth’s atmosphere. The famous Tunguska event in 1908, which flattened thousands of hectares in Siberia, was caused by a similar-sized object.

In light of this possible scenario, the international scientific community activated its near-Earth object (NEO) monitoring protocols and developed a plan to observe 2024 YR4’s orbit more precisely. This brought one of today’s most advanced instruments into play: the James Webb Space Telescope.

The Webb’s Infrared Eye in Action

The James Webb Space Telescope, specialized in infrared observations of the Universe, was directed at the asteroid on March 26, 2025. Its NIRCam and MIRI instruments captured precise images and thermal measurements of 2024 YR4, which were key in estimating its size and composition.

Thanks to these observations, the asteroid’s diameter was determined to be approximately 60 ± 7 meters. This level of accuracy allows scientists to fine-tune orbital models and better understand the asteroid’s thermal behavior, which directly influences its long-term trajectory.

The telescope also helped characterize the asteroid’s albedo (reflectivity), which is crucial in estimating how it absorbs and emits solar heat. These properties influence the so-called Yarkovsky effect, a subtle but constant thermal force that can gradually alter its orbit over time.

With these new data, experts from NASA’s Center for Near Earth Object Studies (CNEOS) updated the prediction models. The best news: the possibility of a collision with Earth in 2032 was practically ruled out. However, an unexpected possibility emerged: a potential impact with the Moon.

A Lunar Impact on the Horizon?

While the Earth threat has been dismissed, the refined analysis suggests about a 2% chance of the asteroid impacting the Moon in December 2032. Although unlikely, this scenario has sparked great scientific interest for the opportunities it could offer.

A controlled or anticipated impact on the lunar surface would offer a unique opportunity to study impact dynamics on airless bodies. It would be possible to observe the crater formation, debris dispersion, and even analyze subsurface lunar material exposed by the collision.

Chart of possible locations (yellow dots) of asteroid 2024 YR4 on December 22, 2032, as of April 2, 2025. NASA JPL/CNEOS

It could also provide key data to understand how to protect future infrastructure on the Moon, such as scientific bases or human habitats. An impact of this magnitude, though minor, could pose risks to ongoing missions if they are near the impact zone.

Even though there is no danger to Earth, monitoring such asteroids is vital. It reminds us that the Solar System is dynamic and that relatively small objects can become protagonists of astronomical—or even geological—events if they interact with planetary bodies.

Cosmic Vigilance and Global Cooperation

The case of 2024 YR4 has once again highlighted the importance of international planetary defense systems. Institutions like NASA, ESA, and the International Asteroid Warning Network (IAWN) collaborate to anticipate and mitigate possible threats.

Collaboration between ground-based and space-based telescopes, like James Webb, enables faster and more accurate coverage. In this case, it was crucial to move from an alarming scenario to a controlled situation in just weeks.

Even so, observations will continue. New study sessions are scheduled for May 2025 to further refine its trajectory, study the thermal evolution of the body, and reduce uncertainties about a possible lunar impact.

2024 YR4 won’t be the first or last asteroid to make us look up at the sky with concern. But it is a clear example of how science, technology, and international cooperation can turn a potential threat into a unique opportunity to learn more about our cosmic neighborhood.

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