Julia Levy, Contributing Photographer

When the world woke up on Sunday, Sept. 29, Earth had an extra moon. 

2024 PT5, a Yale shuttle-sized Asteroid, will orbit Earth until late November. This new “mini-moon” is a wayward asteroid, a space rock smaller than a planet, orbiting the Sun, that was pulled into Earth’s gravitational field. 

Before it became one of Earth’s moons, 2024 PT5 was part of the Arjuna asteroid belt, a cluster of smaller asteroids in orbit similar to Earth’s. So how did this asteroid leave the Arjuna asteroid belt and make its way to Earth?

“Every once in a while, gravitational perversions from Jupiter will toss [an] asteroid onto more oval or elliptical orbits. That’s when you start getting asteroids that could cross the orbit of Earth,” Tiger Lu, a fifth-year graduate student in the Rice Research Group, which studies planetary astrophysics, told the News.

Once it neared Earth, many factors allowed this asteroid to become our planet’s newest moon. All large bodies generate gravitational fields and the Earth is no exception. For 2024 PT5 to now be in orbit around the Earth, the trajectory of the asteroid had to strategically align with the Earth’s revolution around the Sun. 

The asteroid got close enough to Earth’s gravitational field that Earth took control of the asteroid from the Sun. This orbital capture is what makes it a moon. 

The newest moon’s size makes it too dim to view with the bare eye or even an amateur telescope. 

Yet, the Earth is just a temporary home for 2024 PT5. The asteroid is expected to resume its journey through the solar system on Nov. 25. 

“The Earth, the Moon and the Sun are all pulling on each other with their own gravity,” Garret Levine, astronomy doctoral candidate specializing in planetary astrophysics, said. “It will eventually leave the system because it’s on an unstable orbit, it’s kind of a temporary capture.” 

While it’s with Earth, what does this extra mini-moon mean to the average Earth dweller? The tides still rise and fall thanks to our — old — Moon, the Earth still rotates around the Sun, and our days are still 24 hours. However, an asteroid so close to Earth presents an alarming question about possible threats from asteroids. 

NASA has taken that into consideration through the Double Asteroid Redirection Test, or DART, which was a mission that tested planetary defense against near-Earth objects like asteroids.

Dr. Jay W. McMahon who worked as a scientist on the NASA DART project assures to, “not [be] too worried, at least about a big [asteroid]. We are confident that we know where all of the large asteroids are and that none of them will hit the Earth anytime soon.” 

NASA is also launching the Near-Earth Object Surveillance Mission to track smaller asteroids according to Dr. McMahon. The two missions are focused on tracking asteroids and preventing their collision with Earth.

Asteroids were formed at the birth of the solar system.