Science ❯ Astronomy ❯ Comets

Characteristics

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

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