Rubin Observatory Spots an Asteroid That Spins Fast Enough To Set a Record
Astronomers using the Vera C. Rubin Observatory have discovered a record-setting asteroid, known as 2025 MN45, nearly half a mile wide and spinning once every 1.88 minutes -- the fastest known rotation for an object of its size. "This is now the fastest-spinning asteroid that we know of, larger than 500 meters," said Sarah Greenstreet, University of Washington astronomer and lead author of the study. The findings have been published in the The Astrophysical Journal Letters. GeekWire reports: 2025 MN45 is one of more than 2,100 solar system objects that were detected during the observatory's commissioning phase. Over time, the LSST Camera tracked variations in the light reflected by those objects. Greenstreet and her colleagues analyzed those variations to determine the size, distance, composition and rate of rotation for 76 asteroids, all but one of which are in the main asteroid belt between the orbits of Mars and Jupiter. (The other asteroid is a near-Earth object.) The team found 16 "super-fast rotators" spinning at rates ranging between 13 minutes and 2.2 hours per revolution -- plus three "ultra-fast rotators," including 2025 MN45, that make a full revolution in less than five minutes. Greenstreet said 2025 MN45 appears to consist of solid rock, as opposed to the "rubble pile" material that most asteroids are thought to be made of. "We also believe that it's likely a collisionary fragment of a much larger parent body that, early in the solar system's history, was heated enough that the material internal to it melted and differentiated," Greenstreet said. She and her colleagues suggest that the primordial collision blasted 2025 MN45 from the dense core of the parent body and sent it whirling into space. Read more of this story at Slashdot.
Astronomers using the Vera C. Rubin Observatory have discovered a record-setting asteroid, known as 2025 MN45, nearly half a mile wide and spinning once every 1.88 minutes -- the fastest known rotation for an object of its size. "This is now the fastest-spinning asteroid that we know of, larger than 500 meters," said Sarah Greenstreet, University of Washington astronomer and lead author of the study. The findings have been published in the The Astrophysical Journal Letters. GeekWire reports: 2025 MN45 is one of more than 2,100 solar system objects that were detected during the observatory's commissioning phase. Over time, the LSST Camera tracked variations in the light reflected by those objects. Greenstreet and her colleagues analyzed those variations to determine the size, distance, composition and rate of rotation for 76 asteroids, all but one of which are in the main asteroid belt between the orbits of Mars and Jupiter. (The other asteroid is a near-Earth object.)
