I saw this a few days ago on New Scientist – Earth has acquired a brand new moon that’s about the size of a car: https://www.newscientist.com/article/2235427-earth-has-acquired-a-brand-new-moon-thats-about-the-size-of-a-car/. Decided it would make a great Space Saturdays post for this week. A lot more information in the link above. It’s only temporary; they estimated it became attached about 3 years ago and will probably be leaving orbit by April or thereabouts.
Earth might have a tiny new moon. On 19 February, astronomers at the Catalina Sky Survey in Arizona spotted a dim object moving quickly across the sky. Over the next few days, researchers at six more observatories around the world watched the object, designated 2020 CD3, and calculated its orbit, confirming that it has been gravitationally bound to Earth for about three years.
An announcement posted by the Minor Planet Center, which monitors small bodies in space, states that “no link to a known artificial object has been found”, implying that it is most likely an asteroid caught by Earth’s gravity as it passed by.
This is just the second asteroid known to have been captured by our planet as a mini-moon – the first, 2006 RH120, hung around between September 2006 and June 2007 before escaping.
Our new moon is probably between 1.9 and 3.5 metres across, or roughly the size of a car, making it no match for Earth’s primary moon. It circles our planet about once every 47 days on a wide, oval-shaped orbit that mostly swoops far outside the larger moon’s path.
Previous Space Saturdays: https://upsdownsfamilyhistory.wordpress.com/tag/space-saturdays/