- Astronomers recently photographed a small object in a chaotic orbit around Earth.
- It might be a mini-moon - a former asteroid temporarily in Earth's orbit. If so, it would be only the second such object astronomers have seen.
- It could also be space debris - 500,000 pieces of space junk float in low-Earth orbit.
- Astronomers are trying to conduct more research and record more observations before the object leaves Earth's orbit in April.
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Astronomers have captured images of a small space object - only a few meters wide - in a chaotic orbit around the Earth.
It could be a "mini-moon," but it won't be here for long.
The object is set to get ejected from Earth's orbit in April.
The International Astronomical Union's Minor Planet Center has provisionally named the object "2020 CD3," as scientists quickly try to figure out what it is. For now, it's considered a "temporary captured object," the term for a small space object drawn into Earth's gravitational field.
If it's a "mini-moon," it was an asteroid that has been captured by Earth's gravitational pull. If not, there's a much less exciting option: It could be a piece of man-made space junk.
"Either way, this is a very compelling object and needs more data to determine what it is," Grigori Fedorets, the lead astronomer who captured the images of the 2020 CD3, said in an announcement.
Astronomers were able to create the composite photograph of the mini-moon above - which shows it as a small but bright pinprick among vibrant disco-ball-like splashes of light - by focusing high-resolution telescopes on the fast-moving object. The splashes of light are stars that appear as trails because of the mini-moon's motion. Their colors come from the filters used to create this composite.
The images, captured February 24, come from the Gemini Observatory in Hawaii. Researchers Kacper Wierzchos and Teddy Pruyne discovered the object at the University of Arizona's Lunar and Planetary Laboratory in Tucson, Arizona, on February 15.
A mini-moon or space junk?
If the object is a natural rocky satellite, it would be only second mini-moon astronomers have ever seen. The other was seen in 2006 and has since left our purview.
But it could also simply be a piece of space debris, one of the many manmade objects that humans have put into space. The orbiting field of space junk around Earth includes paint flecks and other little pieces from spacecraft, rocket parts that have fallen off or are left over from explosions, nonfunctional satellites, and more.
NASA estimates that there are over 500,000 pieces of space junk in our atmosphere, and most of them orbit at speeds up to 18,000 miles per hour - almost seven times faster than a bullet.
Scientists think the object's reflexivity - the way it reflects light - might help them figure out what it is.
If it's a natural rocky object, it would likely have relatively lower reflectivity than a piece of spacecraft debris.
Still, it's difficult for astronomers to study the object since it's so small - between 1.9 and 3.5 meters, Wierzchos estimated - and far away.
"Obtaining the images was a scramble for the Gemini team because the object is quickly becoming fainter as it moves away from Earth," John Blakeslee, head of science at the Gemini Observatory, said in a release.
Fedorets added that "additional observations to refine its position will help us determine this mystery object's orbit and its possible origin."
Leaving after a chaotic orbit
Wierzchos told Space.com that 2020 CD3 has a "chaotic orbit" - the object is all over the place because it's pulled by both the and Earth.
He tweeted a simulated diagram of the object's orbit since it came close to Earth about three years ago.
But the mini-moon is not slated to stick around.
"It is expected to be ejected from Earth's orbit altogether in April," Blakeslee said in the announcement.
(2/3) The object has just been announced by the MPC and its orbit shows that it entered Earth's orbit some three years ago. Here is a diagram of the orbit created with the orbit simulator written by Tony Dunn: pic.twitter.com/2wsJGtexiO
- Kacper Wierzchos (@WierzchosKacper) February 26, 2020