Astronomers have discovered a new interstellar visitor, 3I/ATLAS, which is believed to be the oldest comet ever observed. The comet is estimated to be around 7 billion years old.

As 3I/ATLAS approaches the sun, astronomers expect its frozen ices to sublimate, releasing gas and forming a glowing coma and tail—the signature features of a comet.

However, new research has shown this potentially "water ice-rich" visitor could be even more extraordinary than initially ...

The icy traveler, called 3I/ATLAS or Comet ATLAS, was discovered on July 1 by the NASA -funded ATLAS survey telescope in Río Hurtado, Chile. This enormous space snowball came from the direction of the ...

A mystery interstellar object spotted last week by astronomers could be the oldest comet ever seen, according to scientists.

A mystery interstellar object discovered last week is likely to be the oldest comet ever seen—possibly predating our solar ...

Emily Kwong and Regina Barber of NPR's Short Wave talk about a comet visiting from interstellar space, caterpillars that eat ...

The ATLAS (short for Asteroid Terrestrial-impact Last Alert System) is a NASA-funded program developed by the University of ...

For only the third time in recorded history, an interstellar object has crossed into our solar system, creating quite the ...

COLUMBUS, Ohio — In a cosmic first for this decade, astronomers have identified a mysterious comet from another galaxy — ...

Just the third-ever confirmed interstellar object has been detected in our solar system. Here's what we know. (Spoiler: It's ...

Astronomers tracking an interstellar object flying through the solar system think it comes from a star at least 8 billion ...