Earth has a new otherworldly resident but we doubt it has been paying rent while it's here. A mini-moon is orbiting our planet and it's actually a small asteroid. But don't let the mini part fool you, this celestial object is about the size of a car. Although our world's newest resident was only just discovered on the night of February 15, 2020, it may have been drawn to our planet all the way back in 2017. Kacper Wierzchos and Theodore Pruyne, both astronomers with the Catalina Sky Survey, a NASA-funded project, spotted the asteroid that night and the rest is history. It has now been named 2020 CD3 and is between 1.9 and 3.5 metres in diameter, or 6.2 and 11.4 feet. "Orbit integrations ... indicate that this object is temporarily bound to the Earth," said the International Astronomical Union's Minor Planet Centre in an announcement about the mini-moon on February 25. This natural satellite might seem small in comparison to our planet and the moon itself but it's a really big deal that it is even just here hanging around our planet. Wierzchos said on Twitter that out of about one million known asteroids, "this is just the second asteroid known to orbit 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 Wierzchos (@WierzchosKacper) February 26, 2020 (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 (3/3) The object has a diameter between 1.9 - 3.5 m assuming a C-type asteroid albedo. But it's a big deal as out of ~ 1 million known asteroids, this is just the second asteroid known to orbit Earth (after 2006 RH120, which was also discovered by the Catalina Sky Survey).— Kacper Wierzchos (@WierzchosKacper) February 26, 2020 Still, this little celestial object won't become a permanent fixture around the Earth in space. In an animation of its orbit, it makes long and looping orbits around our planet and it was on a particularly close pass that it was finally spotted. According to The Weather Network, that might have been it's last ever pass around the planet and is probably on its way out of its gravitational pull, never to return again. Earth may have a new minimoon. C26FED2 may have spent the last 3 years orbiting Earth after being captured through L1. This simulation is in a rotating frame which keeps L1 and L2 stationary. Read @BadAstronomer's blog on minimoons. https://t.co/EqhmCf1Flhhttps://t.co/dAQHbA3skC pic.twitter.com/3NHqNKdTe3— Tony Dunn (@tony873004) February 16, 2020 According to CBC, these kinds of visitors only stick around for a short period of time because they get pulled by the Earth, the moon, and the sun's gravity all at the same time. Space is full of amazing things like this mini-moon even if we can't see it from all the way down here on the ground. For things we can see, there will be four super moons in a row this year and yesterday, Venus and the moon swapped places in the sky.
