Earth is saying goodbye to a small asteroid named 2024 PT5, which has been moving near our planet for the past two months. People call it a "mini moon," but it’s not a real moon because Earth's gravity never fully captured it. Instead, the asteroid moved in a unique, curved path around Earth, shaped like a horseshoe, after it was first seen in August.

On Monday, the asteroid will move away from Earth because the sun’s gravity is pulling it more strongly. But it will come back for a short visit in January. Scientists say it will pass safely by Earth, staying about 1.1 million miles (1.8 million kilometres) away.

Raul de la Fuente Marcos, an astrophysicist who, along with his brother Carlos, identified the asteroid’s “mini moon behaviour,” said, “By the time it returns next year, it will be moving too fast—more than double its speed from September—to hang around.”

NASA to study the space rock in January

The asteroid is about 33 feet (10 meters) wide and might be a piece of rock knocked off the moon by another asteroid hitting it. NASA wants to learn more about it. In January, they will use a special radar in California to study the asteroid and understand where it came from and how it moves.

At the moment, the asteroid 2024 PT5 is very far away, over 2 million miles (3.5 million kilometres), and too dim to see without a strong telescope. When it comes back in January, scientists will use radar to study it and learn more about it.

The asteroid is expected to pass by Earth again in 2055, but like now, it won’t stay for long. The sun’s gravity controls its path, making it an interesting visitor, but only for a short time.