Exciting Celestial Event

This Sunday, September 29, marks an exciting celestial event for Canadians and stargazers across the world! At precisely 3:54 p.m. Eastern Time, Earth will attract a temporary mini-moon, providing a unique opportunity to witness a fascinating astrophysical occurrence. Just after this moment, onlookers will also see a waning crescent moon setting in the western sky around 6 p.m.

What is the Mini-Moon?

The mini-moon in question is officially designated as asteroid 2024 PT5. Unfortunately, this cosmic companion is quite diminutive, measuring only about 10 meters in diameter—similar in size to an average house—paling in comparison to our well-known moon, which boasts a massive diameter of approximately 3,500 kilometers. Due to its small size and distance—nearly ten times further from Earth than the Moon—2024 PT5 will remain elusive to the naked eye.

Temporary Satellite of Earth

This mini-moon represents more than just a fleeting visual delight. It will be a temporary satellite of Earth until November 25, when it will escape our planet's gravitational pull and return to the small asteroid belt from which it originated. As astronomer Carlos de la Fuente Marcos explains, "The object that is going to pay us a visit belongs to the Arjuna asteroid belt, a secondary asteroid belt comprised of space rocks that share orbits similar to that of Earth." This exciting visit is made possible thanks to the Asteroid Terrestrial-impact Last Alert System (ATLAS), a NASA-funded robotic survey aimed at tracking near-Earth objects.

Past Mini-Moons

Before 2024 PT5, Earth has temporarily captured other mini-moons on several occasions, with two recorded "short captures" that lasted for weeks or months. Despite being a rarity, these events happen a few times each decade. For instance, 2020 CD3, discovered in 2020, was believed to have been circling Earth since 2016 before disappearing from orbit shortly after its detection. Another notable case was 2006 RH120, which spent a few months orbiting our planet in 2007.

Interesting Long-term Companions

For those wondering about Earth's long-term companions, there's an intriguing case known as 2023 FW13. This 20-meter-wide quasi-satellite has been orbiting Earth in a complex path for over 2,100 years and is estimated to remain within our cosmic neighborhood for approximately 1,700 more years!

Conclusion

So while you may not see a second moon shining brightly in our sky this weekend, the fleeting presence of asteroid 2024 PT5 serves as a reminder of the ever-changing dynamics of our solar system. Set your sights on the sky and enjoy the wonders of astronomy as you witness this rare occurrence! Remember to share your experiences, and who knows, you might just inspire others to look up at the cosmos, too!