Particle.news

Download on the App Store

3I/ATLAS Confirmed as Ancient Interstellar Comet From Milky Way’s Thick Disk

Traced to the galaxy’s thick disk with a 7.6–14-billion-year age, 3I/ATLAS will offer direct study opportunities when it sweeps inside Mars’ orbit in October.

Image
That small moving dot is our new interstellar visitor, Comet 3I/ATLAS. A new study said it might be 7 billion years old, or 3 billion years older than our own solar system. Image via ESO/ O. Hainaut.
Image

Overview

  • ESO’s Very Large Telescope imagery showed a hyperbolic trajectory at about 57 km/s and revealed emergent coma formation as 3I/ATLAS begins outgassing.
  • Application of the Ōtautahi–Oxford interstellar object population model with Gaia data pinpointed the comet’s origin in the Milky Way’s thick disk, a first for this population.
  • Research led by Matthew Hopkins estimates the object’s age between 7.6 and 14 billion years and indicates a water-ice-rich composition predating the 4.6 billion-year-old Sun.
  • Size estimates place the nucleus at roughly 10–20 kilometers across, with a bluer surface hue and redder coma than typical Solar System comets.
  • Ground- and space-based observatories are intensively tracking 3I/ATLAS as it brightens toward its October perihelion inside Mars’ orbit, when activity is expected to peak.