Earth Has Two Moons - Now What?

February 27, 2020

A new visiting ‘mini-moon’ has been orbiting Earth for the past 3 years, but it will soon disappear according to astronomers. Researchers in Tucson, Arizona spotted the small asteroid, dubbed 2020 CD3, on Feb. 15. The object measures about 6 feet to 11 feet across.

Photo of Two Moons by Enu Carka

Kacper Wierzchos, a researcher with The Catalina Sky Survey, a NASA-funded project, at the University of Arizona’s Lunar and Planetary Lab, tweeted the news on 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.”

The second moon has been officially cataloged by the International Astronomical Union’s Minor Planet Center on Tuesday. The center collects observational data on asteroids, comets and natural satellites in the solar system.

In its official designation, the center said observations “indicate that this object is temporarily bound to Earth.” The organization added: “No evidence of perturbations due to solar radiation pressure is seen, and no link to a known artificial object has been found. Further observations and dynamical studies are strongly encouraged.”

The asteroid is expected to leave Earth’s orbit in April and return to orbit around the sun. The last asteroid to get caught in Earth’s orbit was 2006 RH120. RH120, which orbits the sun and passes near Earth every few decades, was captured by the planet’s gravity in June 2006 and stayed until around September 2007, before returning to heliocentric orbit.

More information about the mini-moon will be revealed as astronomers continue to observe it.