A recent study has revealed that Earth has a “new moon,” or more accurately, a new quasi-satellite.
A quasi-satellite is an astronomical body that orbits Earth but is primarily bound by the Sun’s gravitational pull.
Astronomers have discovered a new “quasi-satellite” of Earth. (Image credit: Shutterstock)
The quasi-satellite, named 2023 FW13, was discovered by experts using the Pan-STARRS telescope located on the summit of Haleakalā volcano in Hawaii. This is one of the few known quasi-satellites.
Experts believe that this cosmic “companion” has been near Earth since 100 BC and will continue to orbit our planet for at least another 1,500 years, until the year 3700 AD.
Fortunately, both 2023 FW13 and a similar quasi-satellite named 469219 Kamoʻoalewa pose no threat to humans on Earth.
Quasi-satellites, also known as co-orbital objects, typically orbit Earth in a manner similar to our natural satellite, the Moon.
However, they are termed “quasi” because they are bound by the Sun’s gravitational force rather than Earth’s, unlike the natural Moon.
2023 FW13 differs from the natural Moon as it orbits outside of Earth’s Hill sphere. The Hill sphere is the region surrounding a planet where its own gravity is the dominant force attracting satellites.
Earth’s Hill sphere has a radius of 1.5 million kilometers, whereas the radius of 2023 FW13’s orbit around Earth is slightly larger, approximately 2.57 million kilometers.
This distance equates to 0.18 astronomical units, which is significant enough that Earth plays a negligible role in the motion of this quasi-satellite.
