Topline
Earth will temporarily get a second moon next week when a tiny asteroid begins its two month orbit around the planet, though researchers say the space rock likely won’t be visible without the help of a professional telescope.
Key Facts
NASA-funded scientists discovered a tiny asteroid—which they named 2024 PT5—on August 7, using the Asteroid Terrestrial-impact Last Alert System in South Africa during routine monitoring, according to a recent study published in Research Notes of the American Astronomical Society.
The asteroid came from the Arjuna asteroid belt, which is a group of asteroids 93 million miles away that follow Earth-like orbits, and will temporarily join the moon in its orbit around the Earth next week, becoming a mini-moon.
Asteroid 2024 PT5 is about the size of a bus, standing at around 33 feet long, and researchers predict it will make a horseshoe-like orbit around Earth instead of a full rotation around the planet.
Though the mini-moon will only be in Earth’s orbit for about two months, it’ll stay close to the planet for a few months, making its closest approach in January 2025, after which it’s expected to make a return to the planet’s orbit in 2055, according to the study.
When Will The Mini-Moon Orbit Earth?
Asteroid 2024 PT5 will begin its roughly 57-day orbit around Earth on September 29, and it will end on November 25.
What Is A Mini-Moon?
When asteroids approach Earth, they typically either fly by the planet, or they hit it and leave a streak in the sky or a dent in Earth’s crust. However, in more rare cases they are captured by Earth’s gravitational pull, becoming a mini-moon, according to the Planetary Society. Mini-moons orbit Earth for a short timeframe, typically less than a year on average. In order to be considered a mini-moon, a space body must reach Earth at a range about 2.8 million miles and at a steady space of around 2,200 mph, Carlos de la Fuente Marcos, the study’s lead author and professor at Universidad Complutense de Madrid, told Space.com. Once 2024 PT5 completes its orbit, it will return to the Arjuna asteroid belt.
Can You See The Mini-Moon?
Unfortunately, the mini-moon won’t be visible by the naked eye due to its size, according to the study. The asteroid is also “too small and dim for typical amateur telescopes and binoculars,” according to Marcos. Professional-grade telescopes with a diameter of at least 30 inches and a charge coupled-device or complementary metal oxide semiconductor detector are needed to see the mini-moon, he said.
Surprising Fact
Asteroid 2024 PT5 may be a piece of Earth’s moon. The asteroid’s previous motion suggests it’s “possibly a piece of ejecta from an impact on the moon,” Paul Chodas, the director of the Center for Near Earth Object Studies at NASA’s Jet Propulsion Laboratory, told The New York Times.
Key Background
Asteroids are made up of the leftover remnants from when the solar system formed around 4.6 billion years ago, according to NASA. NASA has taken the threat of an asteroid coming into contact with Earth more seriously in recent years. In 2022, it carried out its first Double Asteroid Deflection Test, which changed an asteroid’s orbit. NASA launched a spacecraft into space and hit the asteroid, shortening its orbit by 32 minutes. NASA also sent the OSIRIS-REx spacecraft on a mission to an asteroid near Earth called Bennu in order to study it. The spacecraft collected samples of the asteroid and dropped them off on Earth in September 2023, though the findings haven’t been made public yet. Scientists believe Bennu has a chance to collide with Earth in 2182, so that’s why research is being conducted on the asteroid. The scientists with the OSIRIS-REx mission believe Bennu has a one-in-2,700 chance of hitting a Texas-sized portion of Earth in 2182, according to a 2023 paper published in Icarus.
