Astronomers have discovered the last half of Earth’s moon

has land Added its 7th confirmed pseudo-moon. This is asteroid 2025 PN7, a small Apollo-type star that was only discovered in August thanks to its brightness thanks to the Panstars 1 space telescope.

After analyzing the trajectory, scientists concluded that the object has a 1:1 resonance with the Earth. In other words, it orbits the Sun at the same time as our planet. From a distance, this coincidence looks like the Earth has collided with a small asteroid – like it has an extra moon.

Unlike the Moon, half moons are not gravitationally bound to Earth. They are cosmologically random companions that follow their own path around the Sun. Only at times do they come so close as to appear closed. In the case of 2025 PN7, its minimum distance is 299,000 km, while at its most distant point it may reach 17 million km. For comparison, the Moon stays at an average distance of 384,000 km from Earth.

According to an article published in the journal AAS Research Notes, The asteroid has been in the semi-satellite phase since 1965 and is expected to remain in this phase for 128 years. Some researchers estimate that 2025 PN7 will finally disappear in 2083.

Why does Earth have a half moon?

So far, seven bodies have been confirmed that appear to be in orbit with the planet. Astronomers believe that more may be discovered in the future. The Earth is a natural semi-moon deposit because the Earth’s orbit is similar to that of some nearby bodies that reside in the group of asteroids called Arjuna, a population that has only recently begun to be studied in detail.

The Arjuna cluster does not form a ring like the asteroid belt between Mars and Jupiter, but is a near-Earth mass of rocks that orbits the Sun in a similar path to our planet. Sometimes, some of these stars pass through us and are classified as crescent moons or small moons depending on their orbital dynamics.

The semi-lunar moon 2025 PN7 is located far from Earth in the Arjuna asteroid group.Image: Sami