Meet the Interstellar Comet 3I/ATLAS

What exactly is 3I/ATLAS?

• 3I/ATLAS (also designated C/2025 N1 (ATLAS)) is a rare visitor to our Solar System coming from outside it. Astronomers have classified it as an interstellar object because its orbit is hyperbolic (not bound to the Sun).
• It was discovered on July 1, 2025 by the Asteroid Terrestrial‑impact Last Alert System (ATLAS) telescope in Chile.
• Why the name? The “3I” means it’s the third confirmed interstellar object (I = interstellar) passing through our neighbourhood. After 1I/ʻOumuamua (2017) and 2I/Borisov (2019), this is number three.
• Scientists estimate its size is uncertain (because of surrounding gas/dust “coma”), but it may be up to a few kilometres across.

In short: 3I/ATLAS is a cosmic wanderer — icy-rocky, coming from another star system, plunging into our Solar System then heading back out.

2. What has NASA (and other scientists) said about 3I/ATLAS?

• NASA states 3I/ATLAS will make its closest approach to the Sun (perihelion) around October 30, 2025, at about 1.35–1.40 astronomical units (AU) from the Sun (1 AU = distance Earth–Sun) which is roughly 125–210 million km.
• NASA emphasises there is no threat to Earth: the comet will not come anywhere near enough to pose a danger.
• Observations from NASA’s instruments (for example the Neil Gehrels Swift Observatory) have detected OH (hydroxyl) emissions from the comet — a sign of water splitting, meaning the comet is active even far from the Sun.
• NASA also provides multimedia/tracking tools (e.g., “Eyes on the Solar System”) to let researchers and sky enthusiasts follow 3I/ATLAS.
• The European Space Agency (ESA) and other observatories are also involved in the global observing campaign.

So, NASA and its partners are taking this very seriously — scientifically exciting, but not dangerous.

3. Will the comet be visible from Earth? (And from India?)

From Earth overall:

• Unfortunately, for naked-eye visibility, chances are very low. According to the Wikipedia summary of 3I/ATLAS: at its best, it may only reach about magnitude ~11.5 (which is far too faint for the unaided eye) and not easily visible in small binoculars.
• The comet went into solar conjunction around late September / October 2025 — meaning it was very close to the Sun in the sky from our viewpoint, hidden in the Sun’s glare and thus not observable from Earth during that time.
• After its perihelion it might become observable again with good telescopes (not naked eye) in November/December-2025 as it moves away.

From India (or other locations):

• Because the comet is very faint and was behind the Sun for a key part of its approach, viewing from India will be even more challenging.
  • The faintness means you’ll need a reasonably large telescope, dark skies, and optimal timing.
  • The fact that it is close to the Sun in the sky for much of its perihelion means it may not be at a favourable angle for observers in India during that period.
• In practice: It’s unlikely that casual sky-watchers in India will see 3I/ATLAS with the naked eye or simple equipment. Dedicated astronomers with good gear might attempt it later in 2025/2026 as the comet recedes and elongation from the Sun improves.

Short answer: No, it’s not likely visible to the casual observer in India at this time. A good telescope + dark sky + correct timing might enable a detection later.

4. Why is 3I/ATLAS so interesting?

• Because it’s interstellar: It didn’t originate in our Solar System. That makes it a rare opportunity to study material from another star system — giving clues to how planetary systems elsewhere form.
• Its composition appears unusual: Early spectroscopy shows a high CO₂/H₂O ratio (meaning much more carbon-dioxide than water, compared with typical Solar System comets) and active behaviour far from the Sun.
• It helps refine our understanding of how frequent interstellar visitors are — we have only seen 1I/ʻOumuamua, 2I/Borisov and now 3I/ATLAS. So each one adds important data.
• Its behaviour differs: E.g., outgassing far from the Sun, hyperbolic speed, unusual polarisation measurements.

5. Quick Q&A Summary

• Is the 3I/ATLAS visible from India?
  No, not in any practical sense — at least not for naked eye. With a large telescope & good conditions maybe later in the year, but for standard sky-watchers it will be very difficult.
• What has NASA said about the 3I/ATLAS?
  NASA confirms it’s an interstellar object, safe for Earth, active and being closely studied. They are observing with multiple instruments and encouraging global observation campaigns.
• What is the interstellar comet 3I/ATLAS?
  It’s the third known interstellar object (thus “3I”), discovered July 2025, with a hyperbolic orbit indicating it came from beyond our Solar System, now passing through and heading out again.
• Will the comet 3I/ATLAS be visible from Earth?
  Not for naked-eye observers. Observability is hindered by its faintness, its position near the Sun for part of its passage, and the fact that it never comes very close to Earth. Specialized instruments/telescopes stand the best chance.

6. Final thoughts for sky-watchers

Even though 3I/ATLAS might not dazzle in the night sky like bright comets of legend, it offers excellent scientific value. If you’re an astronomy enthusiast in India (or anywhere), here are some tips:

• Stay tuned to astronomy updates: when the comet emerges from behind the Sun and its solar elongation improves.
• Use cameras/telescopes with digital “stacking” or long-exposure ability to detect faint objects.
• Dark skies away from city lights will help.
• Follow live streams or robotic-telescope feeds (some observatories may show it).
• Enjoy the rarity: to have an interstellar object passing through is still a relatively unusual event.