3I/ATLAS Comet Viewing in US: When and Where to See the Rare Interstellar Visitor — Dates, Timings, and Key Details
Interstellar comet 3I/ATLAS, estimated to be 7 billion years old, will be visible across the US from early November to mid-December 2025. Check best viewing dates, times, and locations.
3I/ATLAS Comet Viewing in US: When and Where to See Rare Interstellar Visitor
A rare celestial spectacle is set to light up American skies this month as interstellar comet 3I/ATLAS makes its journey through our solar system. Discovered in July 2025, the ancient comet — estimated to be around 7 billion years old — offers skywatchers a unique opportunity to witness material from beyond our solar system.
According to astronomers, 3I/ATLAS reached its closest point to the Sun (perihelion) on October 30, 2025, coming within 1.4 astronomical units (AU) of it. The comet will then pass roughly 1.8 AU (269 million km) from Earth on December 19, 2025.
This marks only the third confirmed interstellar object to visit our solar system, following ʻOumuamua (2017) and 2I/Borisov (2019) — making it a once-in-a-lifetime event for space enthusiasts.
🪐 When to View Comet 3I/ATLAS in the US
The time frame in which comet 3I/ATLAS can be best seen from the U. S. is going to be thus: beginning of November till the middle of December in 2025, with the possibility of seeing it about an hour and a half before sunrise—when the sky is dark and the horizon is free from obstructions.
The comet's brightness will fluctuate between magnitude 12 to 18 thus making it impossible to see it with bare eyes—only through a large amateur telescope (of 10-inch aperture or more) will its presence in the form of a faint, slow-moving dot in the sky be revealed, provided the viewing area is very dark and rural.
📍 Where to Watch in the US
Visibility will depend on your location, light pollution, and weather. Here’s a regional breakdown of the best windows for observation:
- Arizona, New Mexico, Texas: November 5 – December 10
- Southern California, Nevada: November 10 – December 15
- Florida, Georgia, Alabama: November 5 – December 10
- Midwest (Kansas, Missouri, Illinois): November 10 – December 5
Astronomers say the Southwestern US and Hawaii will offer the clearest professional-grade views, thanks to their high-altitude observatories and clear skies.
🔭 What Makes 3I/ATLAS Special
Unlike typical comets that orbit the Sun, 3I/ATLAS is an interstellar traveler — it entered our solar system from deep space and will leave it forever once its trajectory carries it beyond the Sun’s influence.
Scientists are using ground-based observatories and space probes to study its composition, motion, and brightness, hoping to learn how it compares to comets born within our solar system.
As NASA and global observatories monitor its passage, 3I/ATLAS offers a glimpse into the building blocks of other planetary systems that formed billions of years ago — long before Earth itself existed.
