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 Water Ice 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 Mass and Size 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