Mini-moon: Earth has pulled an asteroid into its orbit
Meet our mini-moon, an asteroid pulled into orbit around the Earth. (Kacper Wierzchos/Catalina Sky Survey)
It's not the moon, but you can call it mini-moon. 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 discovery was made by Kacper Wierzchos and Theodore Pruyne, researcher specialists for the Catalina Sky Survey. It's a NASA-funded project at the University of Arizona's Lunar and Planetary Laboratory in Tuscon, Ariz.
The survey is supported by the Near-Earth Object Observations Program, which reports into NASA's Planetary Defense Coordination Office. Specialists at Catalina help NASA discover and track near-Earth objects that could be potentially hazardous to the planet.
In this case, they found a natural satellite that was pulled into Earth's orbit three years ago.
On Tuesday, the Smithsonian Astrophysical Observatory's Minor Planet Center announced the object. The MPC is "the single worldwide location for receipt and distribution of positional measurements of minor planets, comets and outer irregular natural satellites of the major planets."
"Orbit integrations indicate that this object is temporarily bound to the Earth," according to the announcement on its site. "No link to a known artificial object has been found. Further observations and dynamical studies are strongly encouraged."
The asteroid is likely between 6.2 feet and 11.4 feet in diameter, the researchers said on Twitter.
The first known asteroid to orbit Earth, asteroid 2006 RH120, was discovered using the Catalina Sky Survey in September 2006. It's known as a TCO, or Temporarily Captured Object to astronomers.
"The story of 2006 RH120 is not without controversy however, as it's orbit appears similar to some Apollo-era spent rockets boosters, and therefore some scientists believe it may be an artificial object," according to the survey's website.
With increasing capabilities of surveys, it's likely that more temporarily captured objects "will be discovered in the coming years, allowing for improved definition and characterization of this strange class of near-Earth objects."