Earth is set to play host to a “mini-moon” this week, as a small asteroid about the length of a double decker bus enters the planet’s orbit. The temporary guest, called 2024 PT5, is set to arrive on September 29 and is expected to befriend the regular Moon for around two months.
Daniel Brown, associate professor in astronomy at Nottingham Trent University, explained that a mini-moon is a small object orbiting another solar system body, which could be either just a rock (an asteroid) or a mixture of rock, dust, and ice (a comet). These mini-moons do not orbit around Earth forever but for a short amount of time.
2024 PT5, first discovered in August last year, belongs to the Arjuna asteroid belt and will orbit Earth for 57 days before eventually moving out of the planet’s gravitational pull. Although not visible to the naked eye, this mini-moon can be observed through telescopes used by professional astronomers.
According to Prof Brown, mini-moons like 2024 PT5 are common but not always easy to observe due to their small size, faint appearance, and fast movement. This asteroid is part of the near Earth object (NEO) group, which consists of space rocks that pass by Earth regularly.
While this mini-moon poses no threat to Earth, it is an interesting example of the complexity of orbits in our solar system. Interestingly, scientists predict that 2024 PT5 will be captured by Earth’s gravity again in 2055. In the past, Earth has had another mini-moon named 2020 CD3, which orbited the planet for over a year.
The arrival of 2024 PT5 serves as a reminder of the diverse and intriguing objects that traverse our solar system, capturing the fascination of astronomers and space enthusiasts alike.