We might be seeing double soon — well, kind of. This fall, Earth will temporarily welcome a mini-moon: a tiny asteroid named 2024 PT5. Spotted by NASA-funded scientists on August 7, 2024, this space rock will begin its two-month orbit around our planet on September 29, 2024.
Earth’s gravity will capture 2024 PT5, enabling it to follow a horseshoe-shaped orbit around our planet. Since it possesses negative geocentric energy, it cannot escape Earth’s gravitational pull. However, after its time as a mini-moon, 2024 PT5 will transition back to heliocentric energy — meaning it will resume its orbit around the Sun like other planets and near-Earth objects.
After leaving Earth’s orbit, it won’t drift too far. The asteroid will remain in our vicinity for a few months before heading back out into space, and it is expected to return to our orbit again in 2055 — about 30 years from now!
🌝 What You Need to Know About This “Second” Moon / Mini-Moon:
➡️ How was it discovered?
2024 PT5 was found using the Asteroid Terrestrial-impact Last Alert System in South Africa.
➡️ What’s the size of this mini-moon?
At 33 feet long, this asteroid will follow a unique horseshoe-shaped path rather than completing a full orbit around Earth.
➡️ How long will it be in our orbit?
The mini-moon will be in our orbit from September 29 to November 25, 2024. According to a report by CBS News, “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.”
As previously mentioned, the asteroid will remain in our vicinity for a few months before heading back out into space with its closest approach in January 2025.
🌚 What is a Mini-Moon?
Mini-moons are asteroids temporarily captured by Earth’s gravity, reports NPR. Typically, they orbit for less than a year. To qualify as a mini-moon, an asteroid must approach Earth within about 2.8 million miles and travel at a speed of around 2,200 mph. Interestingly, 2024 PT5 may be a fragment of the Moon — as its trajectory suggests it could be debris from an impact on our natural satellite.
🔭 Can You See This “Second” Moon?
Unfortunately, 2024 PT5 will be nearly impossible to see with the naked eye, according to Space.com. Not even amateur telescopes will work — only professional telescopes of at least 30 inches in diameter can detect it.
While there aren’t any official viewing parties announced in Los Angeles, it’s worth mentioning that the Griffith Observatory collaborates every month with local telescope groups to share their telescopes and expertise with the public. With their help, there’s always something exciting to observe in our skies! You can find more info here.
While you might not see this mini-moon with the naked eye, it’s still a fascinating reminder of the incredible and dynamic nature of the cosmos above us.