Rare Binary Asteroid Discovered

 Scientists at the Arecibo Observatory in Puerto Rico and the Green Bank Observatory (GBO) in West Virginia have both independently confirmed the existence of a binary asteroid system. Known as 2017 YE5, the asteroids made their closest approach to Earth on June 21, coming within 6 million kilometres (3.7 million miles) of Earth.
 First spotted by the Cadi Ayyad University Morocco Oukaimeden Sky Survey in December 2017, the asteroids were initially assumed to be a single asteroid. However after follow-up observations by NASA's Goldstone Solar System Radar, this assumption appeared to be flawed.
 Through observations from Arecibo, GBO and Goldstone, it was found that the two objects revolved around each other once every 20 to 24 hours. In addition, data indicated that the two rocks did not reflect as much sunlight as a typical rocky asteroid meaning 2017 YE5 is likely dark like charcoal.
Further observation also revealed a striking difference in the radar reflectivity of the two objects. This difference hinted that the two objects may have different densities, compositions near their surfaces, or different surface roughnesses.

Read the full press release at: https://www.jpl.nasa.gov/news/news.php?feature=7187