Comet 3I/ATLAS already made its closest pass by Earth on December 19, 2025, at about 06:00 GMT, and it is now moving back outward through the solar system.

Quick answer: when it passed

  • 3I/ATLAS reached closest approach to Earth on December 19, 2025 , around 1 a.m. EST / 06:00 GMT.
  • Even at “closest,” it was about 168 million miles (270 million km) away, nearly twice the Earth–Sun distance, so there was never any impact risk.

What happens next in its journey

  • After passing Earth, 3I/ATLAS is heading toward Jupiter , which it is expected to pass at tens of millions of miles distance in March 2026.
  • It will then cross the orbits of Saturn (2026), Uranus (2027), and Neptune (around 2028) before exiting the outer solar system and heading back into interstellar space in the 2030s.

Can you still see or follow it?

  • 3I/ATLAS is too faint and far to see with the naked eye; only large amateur or professional telescopes can pick it up now.
  • For virtual viewing and tracking, observatories and NASA visualization tools have offered online simulations and past livestream archives of the December 19 flyby.

Why it became a trending topic

  • 3I/ATLAS is only the third known interstellar object to pass through our solar system, after 1I/‘Oumuamua and 2I/Borisov, which made it a hot topic in late 2025 forums and news.
  • Its odd behavior (color changes and hints of non‑gravitational acceleration near the sun) sparked debate ranging from exotic-comet physics to speculative “could it be technology?” discussions in media and online communities.

Information gathered from public forums or data available on the internet and portrayed here.