Astronomers have discovered a skyscraper-sized asteroid, 2025 SC79, which orbits the sun every 128 days, making it the second-fastest known asteroid in the solar system. The asteroid, identified by Carnegie Science astronomer Scott S. Sheppard, was first observed on September 27. It crosses Mercury’s orbit during its 128-day trip around the sun, making it one of the few objects with an orbit inside Venus. The discovery highlights the challenges of tracking such objects, which can be difficult to spot due to their proximity to the sun.
Scientists are using advanced telescopes like the Dark Energy Camera to monitor potential threats to Earth, including ‘planet killer’ asteroids. The NSF’s Gemini telescope and Carnegie Science’s Magellan telescopes were used to confirm the sighting of 2025 SC79, Carnegie Science said. The work, which is partially funded by NASA, aims to identify objects that could pose a risk of crashing into Earth, helping to protect our planet and learn more about the solar system’s history.
The fastest known asteroid was also discovered by Sheppard and his colleagues in 2021, taking 133 days to orbit the sun. This new discovery underscores the importance of ongoing research into near-Earth objects. While the asteroid is now traveling behind the sun and will be invisible to telescopes for several months, its proximity and speed make it a subject of interest for further study.