关于这张图
This series of seven radar observations by the Deep Space Network's Goldstone Solar System Radar shows the asteroid 2011 UL21 during its close approach with Earth from 4.1 million miles (6.6 million kilometers) away – about 17 times the distance between the Moon and Earth. White circles highlight the main asteroid and its small moon (a bright dot at the bottom of the image). Passing Earth on June 27, 2024, the asteroid was discovered in 2011 by the NASA-funded Catalina Sky Survey, in Tucson, Arizona. This marked the first time it came close enough to Earth to be imaged by radar. While the nea…
