On February 15th 2020 a magnitude 20 object designated 2020 CD3 was observed and projected to be in a 47 day elliptical orbit of the Earth. Projections do not all agree yet, but the orbit is believed to be unstable and should not last more than about 3 years. 2020 CD3 is estimated to be between 1 and 6 meters in diameter, though reportage varies wildly on the size estimates. Nobody seems to be commenting on perigee, though the simulation images suggest it is approximately at lunar orbit distance - of course with the 47 day period apogee is well beyond lunar orbit.
This is only the second "captured asteroid" to be observed in Earth orbit, 2006 RH120 was observed to be in Earth orbit from September 2006 to June 2007 - although 1991 VG was weakly captured for a month in 1992 and is expected to return in the future.
Many stories have already been published elsewhere - Wikipedia has already been updated; but, nobody seems to be asking the important questions like: if Pluto can be disqualified as a planet, how can 2020 CD3 be called a moon? ;-) EarthSky was unable to be consulted, perhaps due to the traffic spike, but other astronomers have referred to the object as a TCO - Temporarily Captured Object, while some question if 2020 CD3 is in fact an artificial object like a spent Apollo era booster stage.
"Earth has captured a tiny object and pulled it into orbit.
The asteroid, known as 2020 CD3, is only the second asteroid known to orbit Earth. And while it won't last, this asteroid acts as a temporary mini-moon whirling around our planet."
--The article doesn't expand on why its' orbit is only temporary so I can only imagine that its' orbit is not stable for....reasons.
"In this case, they found a natural satellite that was pulled into Earth's orbit three years ago. "
The article does not say WHEN the orbit may end and... will likely be pulled into collision vector with Earth?
"The asteroid is likely between 6.2 feet and 11.4 feet in diameter, the researchers said on Twitter."
VERY mini-me!
https://www.cnn.com/2020/02/26/world/earth-mini-moon-asteroid-scn-trnd/index.html
(Score: 5, Insightful) by BK on Thursday February 27 2020, @05:48AM (4 children)
“That’s no moon!”
Seriously though, if Pluto can’t be a planet, then calling this small piece of debris a moon is ludicrous.
...but you HAVE heard of me.
(Score: 2, Touché) by Anonymous Coward on Thursday February 27 2020, @06:07AM
"If my motorcycle isn't a car, then this cupcake definitely isn't a cake!"
(Score: 4, Funny) by driverless on Thursday February 27 2020, @02:21PM
Yeah, sorry, I'll just hike these up a bit. Really should see about getting a belt for them.
(Score: 1, Interesting) by Anonymous Coward on Thursday February 27 2020, @04:10PM
What is the cutoff? Officially there are 1 kilometer sized moons of Jupiter and a 300 meter moon of Saturn.
(Score: 0) by Anonymous Coward on Friday February 28 2020, @05:16PM
People say the same thing about my ass, but you can bet if you ever encounter it you'll know you've been mooned.