Astronomers using Gemini Multi-Object Spectrograph (GMOS) A telescope in southern Gemini determined that the recently discovered nearby asteroid 2024 YR4 is one of the largest objects in recent history that could affect the moon, and is likely to originate from the major asteroid belt in the solar system. Their Survey results It will be published in Astrophysics Journal Letter.
This image from the 2024 YR4 was captured at Gemini Southeres Scope in Chile, half of the International Gemini Observatory run by Noallab. Image credits: International Gemini Observatory / Noirlab / NSF / Aura / M. Zamani.
The 2024 YR4 was discovered on December 27, 2024 by the Asteroid’s Ground Impact Last Altar System (ATLAS).
At the time, the asteroids had a close approach to Earth, passing a distance of just 0.017 Au (astronomy unit).
In January 2025, a month after its discovery, the 2024 YR4 exceeded the International Asteroid Warning Network (IAND) notification threshold, which was predicted on December 22, 2032, with a 1% chance of future impact on Earth.
The asteroid misses Earth during this encounter, but there is still a few percent remaining chance that it could hit the moon instead.
Now interested in characterizing famous asteroids, Eureka scientific Athleton Mar Bryce Borin A colleague used a Gemini Southeres scope to capture images of the 2024 YR4 at several different wavelengths.
A detailed analysis of the asteroid LightCurve allowed the team to determine its composition, orbital properties and 3D shape.
“Our observation with Gemini South provided an important part of the puzzle in determining the characteristics of the 2024 YR4,” Dr. Bolin said.
“Studying this asteroid could be an Earth impactor and was crucial in understanding the poorly understood Earth Cross population.”
Information collected from the light curve indicates that the 2024 YR4 is likely an S-type asteroid. In other words, it has a silicate-rich composition.
The reflective pattern suggests a diameter of approximately 30-65 m (98-213 feet), making it one of the largest objects in recent history and affects the moon.
It is unlikely, but if it affects the moon, the asteroid would provide an unprecedented opportunity to study the relationship between the size of the asteroid and the size of the resulting impact crater – an amount previously unknown.
Analysis also revealed that the asteroid’s rotation period is about once every 20 minutes, and is shaped like a rare hockey puck.
“The discovery was pretty unexpected as most asteroids are thought to be shaped like potatoes and toy tops rather than flat disks,” Dr. Bolin said.
Based on these orbital characteristics, astronomers determined that the 2024 YR4 is most likely to originate from the main asteroid belt, and that gravity interaction with Jupiter is likely to cause it to be disrupted by its current short-range orbit.
Its retrograde spin direction suggests that it may have moved inward from the central main belt region, adding to its understanding of how small asteroids evolve and reach orbits beyond Earth.
____
Bryce T. Borin et al. 2025. Discovery and characterization of the Asteroid 2024 YR4, which crosses the Earth. apjlin press; arxiv: 2503.05694v2
Source: www.sci.news
