Aylla Joice Torres 
Prepare for trouble, and make it a double!
There’s no problem in sight, but a second moon will be orbiting our planet, and you should know about it.
Earth will temporarily gain a second moon as a tiny asteroid orbiting around the planet for two months. The asteroid is set to become a mini-moon, revolving around Earth in a horseshoe shape from September 29 to November 25.
When asteroids approach Earth, they typically either fly by the planet or hit it and leave a streak in the sky or a dent in Earth’s crust. However, in 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.
Discovered by researchers at the Asteroid Terrestrial-impact Last Alert System, an asteroid monitoring system funded by the National Aeronautics and Space Administration (NASA), asteroid 2024 PT5 was spotted in August using an instrument located in Sutherland, South Africa.
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. According to their study published in Research Notes of the American Astronomical Society, the asteroid came from the Arjuna asteroid belt, 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 in the coming weeks, becoming a mini-moon.
Scientists from the Universidad Complutense de Madrid have tracked the asteroid’s orbit for 21 days and determined its future path. Earth’s gravitational pull will draw 2024 PT5 towards it and, much like our moon, it will orbit our planet — but only for 56.6 days.
Even after it leaves orbit, it will stay near Earth for a few months, making its closest approach on January 9, 2025. Soon after, it will leave Earth’s neighborhood until its path puts it back into our orbit in about 30 years — in 2055. Earth’s gravity will pull it into its orbit and the asteroid will have negative geocentric energy, meaning it can’t escape Earth’s gravitational pull. It will orbit around Earth in a horseshoe shape before reverting to heliocentric energy, meaning it will rotate around the sun again, like the other planets and Non-Earth Objects (NEOs) in our galaxy.
This isn’t the first time it happened as an asteroid called 2020 CD3 was bound to Earth for several years before leaving the planet’s orbit in 2020 and another called 2022NX1 became a mini-moon of Earth in 1981 and 2022 and will return again in 2051.
Although it is exciting to know that we’ll get a mini-moon, The study’s lead author Carlos de la Fuente Marcos told Space.com the mini-moon will be too small to see with amateur telescopes or binoculars but professional astronomers with stronger tools will be able to spot it. The mini-moon won’t be visible to 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.
The mini moon’s absence from view might leave you feeling a bit let down. Despite the disappointment, each missed sighting highlights the vast and unpredictable universe. While one mini-moon passes unseen, it signals future astronomical wonders and fosters shared enthusiasm among skygazers. The collective acknowledgment that any single missed event is just a small part of our ongoing exploration of the cosmos can be a consolation.
