A11pI3Z is only the third interstellar visitor to be discovered, and astronomers can’t say yet whether it is a comet or a rocky body.

https://www.nytimes.com/2025/07/02/science/interstellar-object-a11pi3z.html?smid=url-share

Resolution criteria

This market will resolve to the classification assigned to A11pI3Z by the International Astronomical Union (IAU) or other authoritative astronomical bodies. Possible classifications include:

• Comet: If A11pI3Z exhibits a coma or tail indicative of sublimating ice.

• Rocky object (including asteroid): If A11pI3Z lacks cometary activity and is determined to be composed primarily of rock or metal.

The resolution will be based on official announcements from the IAU, similar organizations, or a clear report from reputable news sources (NYT, ABC, Washington Post, AP, Reuters) or scientific magazines.

Background

A11pI3Z is the third known interstellar object detected passing through our solar system, following 'Oumuamua in 2017 and Comet 2I/Borisov in 2019. Discovered on July 1, 2025, by the Asteroid Terrestrial-impact Last Alert System (ATLAS), A11pI3Z is currently near Jupiter and moving toward Mars. Its hyperbolic trajectory and high velocity suggest an origin outside our solar system. The object's size is estimated to be approximately 25 miles (40 kilometers) across. (apnews.com)