Third interstellar object A11pl3Z on its way to the sun!

Third interstellar object A11pl3Z on its way to the sun!

A new astronomical discovery is causing a stir in the scientific community: a third interstellar object, tentatively named A11pl3Z, has been discovered and is traveling on a trajectory through our solar system. The discovery was made by an astrophysics student in California who operates under the pseudonym “Astrafoxen” and posted an image of the object on Bluesky. This discovery enabled amateur astronomer Sam Deen to trace the object back to June 14, 2025 on older images from the ATLAS telescope, which enabled the first calculations of its trajectory.

The European Space Agency (ESA) confirmed the observations and said that A11pl3Z is unlikely to have come from our solar system. This would make it the third known interstellar object after 1I/ʻOumuamua and 2I/Borisov. The object is about 20 kilometers in diameter and ESA assures that it poses no threat to Earth. The closest approach to the Sun is expected in October 2025, with the object remaining just outside the orbit of Mars.

trajectory and speed

A11pl3Z is currently moving at a speed of about 66 kilometers per second and is about 735 million kilometers from the Sun, making it difficult to see for now. Astronomers around the world have pointed their telescopes at the object to collect more data. NASA has also added A11pl3Z to its database of near-Earth objects. The object's origin and composition are currently unknown, further fueling scientific curiosity.

ESA said its Planetary Defenders are currently observing A11pl3Z and are also evaluating older data to identify any previous sightings of the object. The object has a hyperbolic trajectory, meaning it originally came from outside the solar system, as stated by David Rankin, an engineer at the University of Arizona. His estimate of the object's eccentricity is around 6, confirming its interstellar origin.

A new star in the sky

The discovery of A11pl3Z comes at an interesting time for astronomy. A lot has happened since the first observation of interstellar object 1I/ʻOumuamua in 2017 and the second interstellar object, comet C/2019 Q4 (Borisov), discovered in 2019. These findings have challenged and alerted our understanding of the abundance of such objects in the interior of our solar system. The ESA explains that such findings suggest that interstellar objects may be more common than previously thought.

Like A11pl3Z, C/2019 Q4 continues to be closely monitored by ESA to gain new insights into its structure and composition. It remains exciting to see what insights these new interstellar objects have in store for the future of astronomy.

For more detailed information about A11pl3Z and the observation of interstellar objects you can visit oe24.at, Visit ArsTechnica and ESA.