Scientists discover Earth has a second (very tiny) moon(Source NBC News) A visiting mini-moon is circling Earth, according to astronomers who discovered the cosmic squatter in our planet’s orbit. The tiny asteroid, dubbed 2020 CD3, was spotted by astronomers in Tucson, Arizona, on Feb. 15.

“BIG NEWS,” Kacper Wierzchos, a researcher with the Catalina Sky Survey at the University of Arizona’s Lunar and Planetary Lab, tweeted Tuesday. “Earth has a new temporarily captured object/Possible mini-moon called 2020 CD3. On the night of Feb. 15, my Catalina Sky Survey teammate Teddy Pruyne and I found a 20th magnitude object.” Wierzchos said that the object measures about 6 feet to 11 feet across and that its orbit suggests that it entered Earth’s orbit around three years ago. He added that the discovery is a “big deal” because, out of roughly 1 million known space rocks, this is “just the second asteroid known to orbit Earth (after 2006 RH120, which was also discovered by the Catalina Sky Survey).” The cosmic interloper was officially cataloged by the International Astronomical Union’s Minor Planet Center on Tuesday. The center, founded in 1947, collects observational data on asteroids, comets and natural satellites in the solar system.