I/Atlas was first spotted on July 1 by the Asteroid Terrestrial-impact Last Alert System (Atlas) survey telescope in Río Hurtado, Chile. At the time it was about 670 million km from the Sun

When the news started to spread on July 1, 2025, about a new object that was spotted from outside our solar system, only the third of its kind ever known, astronomers at Michigan State University—along with a team of international researchers—turned their telescopes to capture data on the new celestial sighting.

I/ATLAS isn't just fascinating because it is the third interstellar visitor found in the solar system; new research suggests it's also the oldest comet ever seen, at over 7 billion years old.