Earth has tiny second moon, and we almost missed it
What's the story
Earth has a new friend in the darkness of space: a 'mini-moon'. The object was caught in the orbit of our planet some three years ago and has just been spotted by a team of astronomers using a ground-based telescope. However, this cute little moon is much different from the one we see daily in the night sky. Here is all about it.
Asteroid
Discovery of space object captured by Earth's gravity
On the night of February 15, Kacper Wierzchos and Theodore Pruyne, astronomers working for the Catalina Sky Survey, spotted a strange blip of light zip across their telescope's screens. They analyzed the movement of the space object in question and concluded that this is possibly a new mini-moon captured temporarily in orbit by the gravity of Earth.
Details
Asteroid as big as a closet
The subsequent observations of the object, now named 2020 CD3, led the Catalina team to suggest that this is most probably a small chunk of carbon-rich C-type asteroid. Their orbital simulations and calculations indicated that the body measures somewhere between 6.2 feet and 11.5 feet in diameter, nearly as big as a closet, and has been circling our planet for the last three years.
Twitter Post
Here's the mini-moon zipping across space
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
Confirmation
Later, Minor Planet Center confirmed the finding
On February 25, days after Catalina astronomers discovered the body, the Minor Planet Center, a branch of International Astronomical Union, confirmed it as a temporarily captured object (TCA). "Orbit integrations indicate that this object is temporarily bound to the Earth," MPC stated while adding that the body doesn't look related to a known artificial object and "further observations and dynamical studies are strongly encouraged."
Future
No word on its future
Often, asteroids passing by near-Earth's neighborhood get captured by the planet's gravity but do not last long enough to be categorized as mini-moons. They either enter the atmosphere and turn into glowing fireballs or skim around the orbit for a bit before their velocity carries them upwards and onwards. That would also happen with 2020 CD3, although we don't know when.
Information
This is the second mini-moon captured by Earth
To note, 2020 CD3 is the second-mini known to have been captured by Earth. The first one was asteroid 2006 RH120, discovered all the way back in September 2006 by the Catalina Sky Survey team.