Astronomers at the Catalina Sky Survey in Tucson, Arizona, who search the skies for potentially hazardous asteroids, recently found one that appeared to have been captured by Earth within the past couple of years. As a result, it is temporarily in our orbit:
Don’t expect to gaze at it or enjoy a walk under its glow. The moon is very small, with a diameter of between 6 and 12 feet.
“It would probably fit in a bedroom, even in San Francisco or New York,” Alessondra Springmann, an astronomer at the University of Arizona, told The New York Times.
Now, more astronomers are trying to observe the object, known as 2020 CD3, to confirm the finding and learn more about it, including where it came from, where it’s headed and when.
“Small objects like 2020 CD3 are often pulled in close to the Earth,” Catalina Sky Survey astronomer Theodore Pruyne told CNN. “This happens when the Earth intersects close enough to asteroids in orbit to the sun. If the object is close enough to the Earth, Earth’s gravity will pull on the objects, changing the object’s orbit.”
Mini-moons ― basically, captured asteroids ― were long theorized, but rarely observed until recently. The Catalina Sky Survey found the only known asteroid/mini moon in 2006; it departed in 2007. That one is now in its own orbit around the sun, which is the predicted fate of the latest mini moon.
“It is heading away from the Earth-moon system as we speak,” Grigori Fedorets of Queen’s University Belfast in the UK told New Scientist. He also predicted it would escape Earth’s orbit by April.
Enjoy it while it lasts.