NASA’s planet-hunting TESS spacecraft just lately caught a view of a really completely different form of cosmic object: interstellar comet 3I/ATLAS.
Throughout a special observation run from Jan. 15 to Jan. 22, the Transiting Exoplanet Survey Satellite tv for pc (TESS) repeatedly noticed comet 3I/ATLAS because it headed out of our photo voltaic system. With its large subject of view, TESS recorded the comet as a brilliant, fast-moving dot dragging a faint tail throughout a crowded starfield.
Scientists like Muthukrishna hope to make use of the dataset to check the comet’s exercise and rotation, clues that reveal how vigorously it is shedding mud and fuel and the way rapidly the comet’s core spins.
TESS measurements put comet 3I/ATLAS’s brightness at about 11.5 in apparent magnitude, roughly 100 times fainter than what we can see with the naked eye, but accessible using telescopes.
NASA’s TESS mission was designed to seek out exoplanets by way of the transit methodology, by which a faraway star dims barely when a planet in its system passes in entrance of it. However TESS’ large subject of view and constant monitoring additionally make it helpful for detecting and monitoring nearer objects, together with comets and asteroids, for longer stretches of time.
This functionality helped astronomers spot comet 3I/ATLAS earlier than they even knew it was there. TESS occurred to look at a comet in May 2025, two months earlier than 3I/ATLAS was found. By wanting again by means of all the info and compiling a number of observations, astronomers may filter out the interstellar customer by means of the noise and observe its actions. Whereas sadly this does not inform us the place the comet originated, it does give us different key particulars.
The January TESS observations are actually publicly accessible and will be discovered on the the Mikulski Archive for Space Telescopes. It is inside these treasured hours that astronomers could discover repeating patterns of brightness that reveal additional secrets and techniques about our transient interstellar customer.
