2020 CD3: Mini-moon That Came Close to Earth Before Drifting Away into Deep Space
Representative image. Credit: Twitter.
A possible mini-moon was temporarily observed by the astronomers earlier this year, which has now drifted away from Earth. Named 2020 CD3, it was only the second asteroid captured from the Earth after 2006 RH120, the first temporary satellite was discovered in September 2006.
What is 2020 CD3?
2020 CD3 is a near-Earth asteroid which comes close to the Earth-Moon system while orbiting the Sun.
On rare occasions like what happened this year, it can temporarily enter the Earth’s orbit. It was first discovered by astronomers Theodore Pruyne and Kacper Wierzchoś at the Mount Lemmon Observatory on February 15 this year.
Researchers of more than six observatories studied the asteroid to calculate its orbit among other characteristics, after which it was confirmed that it was indeed orbiting the Earth.
BIG NEWS (thread 1/3). 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. Here are the discovery images. pic.twitter.com/zLkXyGAkZl— Kacper Wierzchoś (@WierzchosKacper) February 26, 2020
What are the characteristics of 2020 CD3?
The astronomers who studied the asteroid's characteristics found it to be measuring between 1.9 and 3.5 metres diameter. As per the JPL Sentry risk table, 2020 CD3 was estimated to have a mass of 4,900 kg, assuming the diameter to be 2 metres. 2020 CD3 has been classified as an Arjuna asteroid, which are near-Earth objects (NEOs) with orbits similar to Earth.
Why is 2020 CD3 being called a mini-moon?
The asteroid was initially called C26FED2, but after follow up observations was given the name 2020 CD3 by the Minor Planet Center. Having been captured orbiting the Earth and because of its small size, 2020 CD3 has widely been called as a mini-moon of Earth in the media. Astronomers believe that the asteroid may have been captured previously but could not be identified because of its faintness and variable orbit.
“Based on simulations, the average capture time for mini-moons is only nine months, so this was captured for a longer time than is expected,” Grigori Fedorets at Queen’s University Belfast, UK was quoted as saying by New Scientist.
“But this object flew very close to the moon, and that put it into a more stable orbit,” Fedorets added.
Will 2020 CD3 be back?
2020 CD3 will continue orbiting the sun and will approach Earth again in March 2044. But it will be perhaps too far (approach distance of about 3.55 million km) to be captured.
Can 2020 CD3 strike Earth?
The highest probability date on which 2020 CD3 can impact Earth is September 14, 2061. But the impact probability is too low, almost negligible. Even if it did strike Earth, it will pose no threat as it will most likely disintegrate upon entering the atmosphere.