Earth new moon 2024 PT5: Can it be seen?

Earth is about to gain a temporary companion in space – a mini-moon known as 2024 PT5. This near-Earth asteroid NEA) is expected to enter Earth's orbit on 29 September 2024 and remain in orbit for just under two months before being released back into the solar system.

2024 PT5, which is 11 meters in diameter – roughly the size of two giraffes – is classified as an Arjuna asteroid. According to a study published in the *Research Notes of the American Astronomical Society*, the asteroid will be captured by Earth’s gravity as it approaches at a low relative velocity.

The asteroid will depart Earth's orbit on 25 November and resume its journey around the sun. However, it will come close to Earth again on 9 January 2025.

Earth’s mini-moons

Researchers explain that Earth regularly captures near-Earth objects (NEOs) into orbit, calling them "temporarily captured flybys." These mini-moons are generally short-lived, as the objects are eventually pulled back into their solar orbits.

Where is 2024 PT5?

Currently, 2024 PT5 is located in the constellation Draco, in the northern sky. It is about 1.9 million miles (3 million km) away from Earth. Despite its proximity, the asteroid is too faint to be seen with the naked eye or even through standard backyard telescopes. Only professional astronomers using powerful 30-inch telescopes will be able to view it.

Where did 2024 PT5 come from?

Asteroids like 2024 PT5 are believed to originate from the Main Asteroid Belt between Mars and Jupiter. Specifically, 2024 PT5 belongs to the Arjuna asteroid group, which has an orbit similar to Earth's around the sun. As the asteroid approaches Earth on 29 September, the planet's gravitational pull will cause it to temporarily enter orbit.

The asteroid was discovered on 7 August by South Africa's Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope, the same system that recently identified the naked-eye comet A3. 

While Earth’s newest mini-moon will not be visible to most, its brief stay in our planet's orbit is a reminder of the dynamic and ever-changing nature of our cosmic neighbourhood.

Can we see it?

Unfortunately, 2024 PT5 will not be visible to the naked eye, and home telescopes are unlikely to be sufficient.

"The object is too small and dim for typical amateur telescopes and binoculars," Carlos de la Fuente Marcos, one of the authors of the journal entry describing the asteroid, told Space.com.

"However, the object is well within the brightness range of telescopes typically used by professional astronomers," Marcos added.