Millions of asteroids are currently zipping through our solar system, remnants from its early formation. These rocky bodies receive heightened scrutiny when their paths bring them perilously close to Earth, a scenario that astronomers can typically monitor. However, challenges arise with so-called “twilight” asteroids, whose positions behind the sun's glare make detection and tracking exceedingly difficult. This article explores the implications of such asteroids, focusing on the newly identified 2025 SC79, which poses a unique threat due to its speed and proximity to our planet.
The latest addition to the list of twilight asteroids, 2025 SC79, is noteworthy not only for its challenging visibility but also as the second-fastest asteroid ever recorded. With an astonishing orbital period of just 128 days around the sun, its discovery was made by Scott Sheppard, an astronomer at Carnegie Science, using the Blanco 4-meter Telescope equipped with the Dark Energy Camera in September. Subsequent confirmations were made using the Gemini and Magellan telescopes, solidifying the asteroid’s presence in our cosmic neighborhood.
2025 SC79 is estimated to measure approximately 2,300 feet (700 meters) in diameter, making it nearly twice the height of the famed Empire State Building. This substantial size, coupled with its rapid orbit, categorizes it as a “planet killer” asteroid. Sheppard has been on the lookout for such potentially dangerous asteroids, highlighting the need for vigilance in tracking these celestial bodies.
According to Sheppard, “The most dangerous asteroids are the most difficult to detect.” Most asteroids become detectable under the cover of night; however, those near the sun are primarily visible during twilight hours, complicating efforts for astronomers. This unique visibility challenge presents a significant hurdle for scientists who aim to identify potential threats to Earth. Sheppard warns that if detected, twilight asteroids like 2025 SC79 could “pose serious impact hazards.”
While our ability to mitigate natural positions of extraterrestrial objects is limited, Sheppard remains hopeful that further observation of 2025 SC79 may yield valuable insights into its composition and potentially assist in identifying similar asteroids in the future. He notes that many asteroids in our solar system reside in one of two primary belts of space rocks, but perturbations can send some into orbits that are more challenging to detect. “Understanding how they arrived at these locations can help us protect our planet and also help us learn more about solar system history,” Sheppard stated.
The discovery of twilight asteroids such as 2025 SC79 underscores the necessity for ongoing vigilance in monitoring our solar system. As astronomers enhance detection methods and research strategies, our understanding of these potential threats will improve. The knowledge gained from studying such asteroids not only contributes to planetary defense but also enriches our comprehension of the solar system's complex history.