In a notable discovery, astronomers at the Carnegie Institute for Science have identified a new near-Earth asteroid named 2025 SC79. This asteroid resides in a particularly challenging location for observation, nestled in the glare of the Sun. It is the latest addition to the Atira asteroid group, which consists of near-Earth objects that maintain orbits entirely within that of Earth.
The Atira group is notably the least populous category of near-Earth asteroids, and with the addition of 2025 SC79, it now counts 39 members. These celestial bodies are notoriously hard to detect due to their faint light being overshadowed by the Sun. 2025 SC79 is only the second known asteroid that orbits entirely within the orbit of Venus. Furthermore, it intersects the orbit of Mercury and completes its solar orbit in just 128 days, marking it as one of the fastest asteroids, surpassed only by two others that orbit in 115 days.
The discovery was made on September 27 using the Dark Energy Camera attached to the National Science Foundation”s Blanco 4-meter telescope, which is dedicated to hunting hazardous asteroids. The size of 2025 SC79 is approximately 700 meters (around 2,300 feet) in diameter. Although this is smaller than the asteroid responsible for the mass extinction of the dinosaurs, its size is still significant enough to cause widespread devastation if it were to impact Earth.
The observation was subsequently verified by two additional telescopes: the NSF”s Gemini telescope and the Magellan telescopes operated by Carnegie Science. According to astronomer Scott S. Sheppard, “The most dangerous asteroids are the most difficult to detect. Most asteroid research finds these objects in the dark of night, where they are easiest to spot. But asteroids that lurk near the Sun can only be observed during twilight—when the Sun is just about to rise or set. If these “twilight” asteroids approach Earth, they could pose serious impact hazards.”
While much remains to be learned about 2025 SC79, its visibility will diminish as it moves behind the Sun for several months. Once it reemerges, astronomers plan to conduct further investigations to gather more detailed information about its composition and origins. Understanding how these asteroids are positioned can provide insights into their history and assist in planetary protection efforts.
Sheppard concluded, “Many of the Solar System”s asteroids inhabit one of two belts of space rocks, but perturbations can send objects careening into closer orbits where they can be more challenging to spot. Understanding how they arrived at these locations can help us protect our planet and also help us learn more about Solar System history.”
