Artist's illustration of 2024 PT5.
Scientists are tracking what they are calling Earth's "second moon" this week. It's an asteroid 37 feet wide, sailing outside the orbit of the original, larger Moon.
Planetary Science Institute's Mark Sykes says the Earth's gravity captured the object, called 2024 PT5, and put it in a temporary orbit.
"But it only goes partway around that orbit. It's called a horseshoe orbit and the reason why it does this is because the moon is messing everything up. The moon helps to capture it and it will help kick it out."
Sykes notes many similar objects are in the Earth's general neighborhood but have avoided detection and tracking.
"If you are moving slowly enough, then you might get captured into an orbit or a captured flyby situation."
Asteroid 2024 PT5 is 2-point-6 million miles away and can only be seen using large telescopes. Scientists say there's no chance of it colliding with either the Earth or its original Moon.
By submitting your comments, you hereby give AZPM the right to post your comments and potentially use them in any other form of media operated by this institution.