2020 CD3: Mini-moon | 28 Feb 2020

  • In Arizona (USA), the astronomers of the National Aeronautics and Space Administration (NASA)-funded Catalina Sky Survey (CSS) have observed a small object orbiting Earth. It is actually an asteroid with a diameter of about 1.9-3.5 m.
  • It has been named 2020 CD3. It is also called “mini-moon” or the planet’s “second moon”. It is orbiting at a distance farther from Earth.
    • Unlike earth’s permanent Moon, the mini-moon is temporary.
  • When an asteroid’s orbit crosses Earth’s orbit, it can sometimes be captured into the latter orbit. Such an asteroid is called a Temporarily Captured Object (TCO).
    • The orbit of such objects is unstable.
    • They have to contend with the gravitational influence of the existing permanent natural satellite (Moon in earth’s case) as well as that of the Sun.
    • Once caught in a planet’s orbit, such objects usually remain for a few years before they break free and go into an independent orbit around the Sun.
  • According to the researchers, 2020 CD3 was captured into Earth’s orbit over three years ago. CSS previously discovered 2006 RH120, which orbited Earth for some time in 2006 and escaped its orbit in 2007.

Catalina Sky Survey

  • It is a NASA funded project to discover and track near-Earth objects (NEOs). It is based in Arizona in the United States of America.
  • NEOs are asteroids or comets with sizes ranging from metres to tens of kilometres that orbit the Sun and whose orbits come close to that of Earth’s.

Source: IE