Comet 3I/ATLAS streaks across space in new NASA video captured by TESS

NASA’s Transiting Exoplanet Survey Satellite (TESS) has captured a rare and spectacular sight: the interstellar comet 3I/ATLAS sweeping across the night sky during a week-long observation window from 15 to 22 January 2026.

The short video, assembled from TESS image sequences, shows the comet moving steadily against a backdrop of stars — a remarkable view considering how distant and fast-moving these objects are.

This sighting matters because 3I/ATLAS is not just any comet. It is one of only three interstellar comets ever observed passing through our Solar System.

⭐ Why 3I/ATLAS is so special

Most comets seen from Earth were formed in our own Solar System, in regions like the Kuiper Belt or the distant Oort Cloud.

But 3I/ATLAS began its journey in another star system, making it part of an extremely rare class of visitors.

The only other confirmed interstellar comets are:

1I/‘Oumuamua (2017)

2I/Borisov (2019)

This makes 3I/ATLAS the third confirmed interstellar comet, giving astronomers another precious opportunity to study material that formed around a completely different star.

⭐ What TESS captured

TESS, famous for discovering thousands of exoplanet candidates, occasionally records moving objects in its wide-field cameras.

During its January observation run, the spacecraft detected:

the comet’s motion across the field of view

variations in brightness that hint at rotation

possible signs of activity from ice sublimation

fragments or jets emerging from the comet’s nucleus

NASA says these datasets will allow scientists to build a clearer picture of the comet’s:

chemical composition

spin rate

dust production

trajectory through the Solar System

⭐ Why studying interstellar comets is important

Interstellar comets contain material formed around other stars, giving scientists direct access to:

different chemical environments

early planetary system formation clues

organic compounds that may not exist in our region

insights into how common comets are across the Galaxy

Because they move extremely fast and only pass by once, every observation is valuable.

Dr. Karen Collins, part of the TESS science team, said:

“Interstellar comets offer a once-in-a-generation chance to study alien building blocks of planetary systems.”

⭐ How 3I/ATLAS was discovered

Comet 3I/ATLAS was first spotted by the Asteroid Terrestrial-impact Last Alert System (ATLAS), a NASA-funded project that scans the sky for near-Earth objects.

Once its hyperbolic trajectory was confirmed, astronomers realised it was not gravitationally bound to the Sun — a clear sign of interstellar origin.

Follow-up observations showed:

an unusually long tail

brightening patterns different from normal comets

a steep incoming angle from outside the Solar System

⭐ Where is the comet heading now?

3I/ATLAS is currently moving rapidly away after its brief passage through the inner Solar System.

Scientists say we will never see it again — it will continue outward into deep interstellar space, eventually leaving the Sun’s gravitational influence entirely.

This makes the TESS video even more valuable.