Earth now has a second moon? What is 2025 PN7, what do Astronomers say about it? All you need to know

Earth just got itself a second moon, an asteroid named 2025 PN7.

Astronomers have spotted the rock, researchers confirmed this week, saying that it qualifies as a “quasi moon”.

The small space rock has been likely hanging around the Earth for nearly 60 years, yet it was left undiscovered by telescopes.

Who found Earth's second moon?

Researchers at the University of Hawaii were the first ones to spot Earth's second moon 2025 PN7 during a routine telescope survey.

On August 29, the Pan-STARRS observatory located on the Haleakala volcano in Hawaii first captured observations of 2025 PN7.

It was later revealed by archival data that the celestial object has been earth's companion for several decades.

What is 2025 PN7, Earth's second moon?

2025 PN7, earth's second moon, is a quasi-moon — a celestial object that travels almost exactly in sync with Earth.

While the asteroid is not a true moon, it keeps pace with Earth and revolves around the sun in an almost exact manner — so much that it appears to shadow our planet as we orbit.

Quasi-moons are different from temporary mini-moons like 2024 PT5, which occasionally orbit the Earth. The 2024 PT5 orbited the earth for around two months in 2024 and can now be called a fragment in space after it was blasted off by our primary moon.

The newly discovered 2025 PN7, also being dubbed as Earth's second moon, may stay with us till 2083 if its current orbit holds. It is one of the very few known quasi-moons that have orbits near Earth, including Kamo‘oalewa that is also believed to be an ancient lunar fragment.

2025 PN7 is not bound by the Earth's gravity unlike our primary moon, but follows a similar orbit as us.

How big is Earth's second moon?

Earth's second moon 2025 PN7 is small and faint, scientists say, which is precisely why it got unnoticed for so many years.

Astronomers are still trying to understand how big or small this asteroid is, with researchers estimating that it is about 98 feet (30 metres) across and around 62 feet (19 metres) in diametre, according to EarthSky.

According to Carlos de la Fuente Marcos, a researcher at the Complutense University of Madrid, 2025 PN7 can be only detected when it comes close enough to Earth.

“It can only be detected by currently available telescopes when it gets close to our planet as it did this summer. Its visibility windows are few and far between. It is a challenging object,” CNN quoted him as saying.

The space rock is the smallest known quasi-moon yet to have orbited near the earth, de la Fuente Marcos said.

At its closest pass of our planet, Earth's second moon 2025 PN7 swings within 299,337 kilometres of us, he added. As per NASA, it is 384,400 kilometres away from us on an average.

Astronomers have confirmed only eight quasi-moons in total so far.