Earth will temporarily gain a new “mini-moon,” asteroid 2024 PT5, from September 29 to November 25. Discovered on August 7 by NASA’s ATLAS, the asteroid is estimated to be 37 feet in diameter but could range from 16 to 138 feet. It will orbit Earth at a safe distance of 2.6 million miles before returning to a heliocentric orbit. The asteroid poses no collision threat.