Asteroid 2024 YR4 May Strike Moon, Risks to Earth Evaluated

ST. GEORGE, Utah – Asteroid 2024 YR4, initially believed to be on a collision course with Earth, has shifted to a potential impact with the moon, according to recent observations by scientists.

The asteroid, first discovered in December 2024, seemed a threat, with a peak 3.1% chance of hitting Earth on December 22, 2032. However, updated calculations show that it is shifting course and could strike the moon instead. The revised probability for a lunar impact has now increased to 4.3%.

“If YR4 hits the moon, it will be the largest asteroid to have hit the moon in about 5,000 years,” said Dr. Paul Wiegert, a professor of astronomy and physics. “People at home will be able to see the explosion with small telescopes or even binoculars.”

Recent models predict the asteroid could create an impact crater about 1 kilometer in diameter, sending millions of kilograms of lunar debris into space. This debris could potentially endanger astronauts on the lunar surface and satellites that handle vital communication on Earth.

Research led by Wiegert indicates that while the moon would face serious consequences from an impact, Earth likely would not experience significant physical danger. “There’s no danger to anyone on the surface,” Wiegert emphasized. “But any fragments reaching Earth could produce a spectacular meteor shower.”

The asteroid’s size, estimated at approximately 60 meters (200 feet) across, raises concerns. Smaller asteroids, such as YR4, can indeed cause regional devastation if they collide with Earth. Astronomers keep track of such “city killers,” as these near-Earth objects can cause significant damage if they were to strike.

Future observations of 2024 YR4 are planned as it returns to the area near Earth in 2028. Scientists hope to gather more data that may refine estimates of its trajectory and potential risks.

As space agencies continue to monitor this asteroid, the focus of planetary defense is broadening, now including risks to objects that may impact the moon. “We’re expanding our vision to include asteroids headed for the moon as well,” Wiegert said, suggesting a need for a more comprehensive strategy in monitoring these celestial bodies.

The event highlights ongoing efforts to track such asteroids, with models and countermeasures being considered for future close encounters.