Science ❯ Astronomy ❯ Comets

Characteristics

3I/ATLAS Composition Outgassing Chemical Composition Speed 3I/Atlas Non-gravitational Acceleration Tail Water Ice Carbon Dioxide Ratio Color Changes Brightness Tails Hyperbolic Orbit Eccentricity Tail Behavior Orbital Mechanics Mass and Size C/2025 A6 (Lemmon) Gas Emissions C/2025 R2 (SWAN) Mass Loss Size and Composition Nucleus 2I/Borisov Cometary Nucleus Cometary Activity Observation Degassing Carbon Dioxide Ice Visibility 3I/ATLAS Jets Comet Composition Anti-Tail Carbon Dioxide Composition Orbit Trajectory Cometary Gases Nickel and Iron Abundance NASA Findings Hydroxyl Molecules

Interstellar Comet 3I/ATLAS to Make Safe Closest Approach Friday at 167 Million Miles

Fresh multi‑wavelength data highlight unusual chemistry with a sunward anti‑tail, reinforcing NASA’s view of a natural, harmless visitor.

Comets Lemmon and SWAN Poised for Best Viewing Oct. 20–21

New Analysis Says Interstellar Comet 3I/ATLAS Is Far Larger Than First Estimated

Interstellar Comet 3I/ATLAS Tied to New Planet 'Seeding' Hypothesis

Hubble and Infrared Observations Show 3I/ATLAS Is an Active Interstellar Comet

High-Resolution Images Illuminate Ancient Interstellar Comet 3I/ATLAS

Interstellar Comet 3I/ATLAS Unveils Glowing Coma and Tail

Active Interstellar Comet 3I/ATLAS Set for Safe Solar System Passage