A moon is a natural satellite orbiting another body. The key part here is “orbiting.” A moon travels in an elliptical path around another central object. And there is only one object like that going around Earth, and it’s called the Moon, which orbits Earth every 27.3 days.

So what, exactly, is this “new moon”? The object is in fact an asteroid called 2025 PN₇. It was discovered in early August, and it is what is known as a “quasi-moon” of Earth. Quasi-satellites orbit the Sun, not Earth, but they orbit the Sun with a period of about one year. Sometimes these satellites come close to Earth and move along with our planet. Sometime in the 1960s, 2025 PN₇ came close to Earth, and it will travel close to Earth until sometime in the 2080s.

The newly discovered asteroid is not Earth’s only quasi-moon—six others are known. These quasi-satellites are part of a group of asteroids called the Arjunas, which basically have the same orbit around the Sun that Earth does. More than a hundred Arjunas are known, and sometimes these asteroids can become quasi-moons.