TESS probes interstellar visitor 3I/ATLAS to reveal its spin

NASA's exoplanet-hunting telescope TESS observed interstellar comet 3I/ATLAS during Jan. 15–22, compiling a 28‑hour sequence to study the comet’s activity and rotation. The object appeared at about magnitude 11.5, and MIT researcher Daniel Muthukrishna stitched the observations into a video showing its trajectory as it leaves the solar system. Although TESS briefly entered safe mode, causing a time jump, the January data are publicly available, and scientists hope to infer how fast the nucleus spins and how dust and gas are shed from the comet.