This fall, for a limited time, Earth will get a second moon.
According to a study published this week, asteroid roughly the length of a city bus, will be captured by Earth’s gravitational pull and orbit our planet for about two months, becoming a “mini-moon.”
It will spend time with Earth from September 29 to November 25 before returning to its home, an asteroid belt orbiting the sun.
“The object we are going to visit belongs to the Arjuna asteroid belt, a secondary asteroid belt made of space rocks that follow orbits very similar to that of Earth,” Carlos de la Fuente Marcos, a professor at Universidad Complutense de Madrid and the lead author of the research, tells Space.com.
He explained that some of the asteroids in the Arjuna belt can approach relatively close to Earth, about 2.8 m miles (4.5 mkm) away.
Also, going relatively slowly for asteroids – at speeds of around 2,200 mph (3,540 km/h) – their paths are affected more strongly than usual by Earth’s gravity.
“Under these conditions … the object could become a temporary moon of Earth,” he said, adding that this will happen with the asteroid in question starting next week and lasting about two months.
He added that it will not follow a full orbit around the Earth.
The asteroid was discovered on August 7 by the Asteroid Terrestrial-Impact Last Alert System (Atlas). Nasa-funded program.
It is about 10 meters long, which is small compared to Earth’s moon, with a diameter of about 3,474 km.
The object will be “too small and dim for typical amateur telescopes and binoculars,” Marcos added. “However, the object is well within the brightness range of typical telescopes used by professional astronomers.”
The scientists added that they believe the asteroid minimoon will return to Earth’s orbit in 2055.
This is not the first mini-moon that Earth has had. The researchers wrote in their paper that two mini-lunar events occurred in 1981 and in 2022.