3I/ATLAS

Third Interstellar Visitor to Our Solar System

Overview

3I/ATLAS is the third confirmed interstellar object to pass through our Solar System, discovered on July 1, 2025, by the NASA-funded ATLAS telescope in Río Hurtado, Chile. This ancient visitor from beyond our solar system offers scientists a rare opportunity to study material from another star system. [NASA]

Closest to Sun

October 29, 2025

Closest to Earth

~1.8 AU minimum distance

Observation Window

Peak visibility period

Discovery Date

July 1, 2025

NASA

Speed

~137,000 mph

NASA

Age (estimated)

7.6 - 14 billion years

Wikipedia

Eccentricity

6.14 (highest known)

Wikipedia

Analytics Dashboard

Real-time data visualization and comparative analysis of 3I/ATLAS with other celestial objects

Current Distance from Sun
Live Data
Current Velocity
Live Data
Visual Magnitude
Estimated
Distance from Earth
Live Data

Distance from Earth Over Time

Speed Comparison

Orbital Eccentricity Comparison

Composition Analysis

Trajectory Path (AU from Sun)

Visual Magnitude Over Time

Interstellar Visitor Comparison

Solar Radiation Intensity

Solar flux (W/m²) drives sublimation and activity (Inverse Square Law)

Velocity Evolution

Speed changes due to gravitational acceleration near the Sun (Kepler's Laws)

Current Distance from Sun

Current Velocity

Days Until Perihelion

Size Comparison of Interstellar Objects

Coma Size Evolution

Gas cloud expansion driven by sublimation

Gravitational Energy

Energy exchange in hyperbolic orbit

Temperature & Solar Heating Analysis

Visualizing how solar heating affects 3I/ATLAS's surface temperature and activity as it approaches perihelion

Estimated Surface Temperature vs Distance from Sun

Temperature estimates based on blackbody radiation model. Actual surface temperature may vary based on albedo, composition, and rotation.

Gas Production Rates (H₂O, CO₂, CO)

Gas production calculated using sublimation physics. CO₂ dominates at large distances (sublimates at 20K), while H₂O requires higher temperatures (170K) and peaks near perihelion. Production scales with solar flux (∝ 1/r²⁻³).

At Discovery (3.2 AU)

~155 K

(-118°C / -180°F)

Low activity, minimal sublimation

At Perihelion (1.36 AU)

~238 K

(-35°C / -31°F)

Peak activity, maximum sublimation

Sublimation Zone

~183-238 K

Water ice actively sublimates

Distance: 1.36 - 2.3 AU from Sun

CO₂ Dominance

8:1 ratio

CO₂ to H₂O production

One of highest ratios ever observed

Interactive Solar System View

Real-time 2D view of 3I/ATLAS's hyperbolic trajectory through our solar system (view from above)

Note: This visualization is an approximation for educational purposes only. Distances, sizes, and orbital paths are not to scale and are simplified for clarity.

Oct 23, 2025
Sun
Mercury
Venus
Earth
Mars
Jupiter
3I/ATLAS

Current Positions

3I/ATLAS: Loading...
Distance from Sun: Loading...
Distance from Earth: Loading...

Discovery & Timeline

June 14, 2025
Pre-discovery observations captured [NASA]
July 1, 2025
Official discovery by ATLAS telescope, Chile [NASA]
October 3, 2025
Closest approach to Mars [NASA]
October 29, 2025
Perihelion - Closest approach to the Sun (~1.36-1.4 AU) [NASA] [Wikipedia]

Name Breakdown: "3" indicates it's the third known interstellar object, "I" means interstellar, and "ATLAS" refers to the Asteroid Terrestrial-impact Last Alert System discovery telescope. [NASA]

Physical Characteristics

Size & Structure

  • Nucleus diameter: 0.44 - 5.6 km [NASA]
  • Type: Active interstellar object with visible coma and tail [ESA]
  • Orbital eccentricity: 6.14±0.001 (highest of all known interstellar objects) [Wikipedia]

Composition

  • Primary component: Unusually rich in carbon dioxide [Wikipedia]
  • Water: Water vapor detected by Swift telescope [NASA Space News]
  • Other gases: Carbon monoxide [ESA]
  • Activity: Releasing gases as it approaches the Sun [ESA]

Origin & Age

3I/ATLAS likely originated from the Milky Way's thick disk and is estimated to be between 7.6 and 14 billion years old - potentially older than our Solar System itself. Scientists cannot trace it back to its original parent star, adding to its mystery. [Wikipedia]

Real-Time Position & Orbit Tracking

Track the current position of 3I/ATLAS in real-time using official NASA/JPL data and interactive 3D visualizations.

NASA JPL Orbit Viewer

Official NASA orbit visualization tool showing 3I/ATLAS trajectory through the solar system.

Launch NASA Orbit Viewer Note: Search for "3I" or "C/2025 N1" in the small body field

TheSkyLive 3D Tracker

Interactive 3D solar system view with real-time position data from JPL Horizons.

Open 3D Tracker Real-time updates using official ephemeris data

Live Position Data

Current coordinates, distance, and speed from TheSkyLive's real-time tracker.

View Live Data Updated using JPL Horizons ephemeris service

Scientific Observations

Observing Missions

NASA Missions [NASA]

  • Hubble Space Telescope
  • James Webb Space Telescope
  • Swift UV Telescope
  • SPHEREx
  • Mars rovers and orbiters

ESA Missions [ESA]

  • Mars Express
  • ExoMars Trace Gas Orbiter
  • Juice spacecraft

Key Scientific Findings

  • Water detected by Swift telescope [NASA Space News]
  • Displays "extreme negative polarization" - unusual behavior [NewsBreak]
  • Closest observations captured by ESA's Mars orbiters during Mars flyby [ESA]
  • Provides insights into interstellar object composition and star system formation
⚠ Safety Notice: 3I/ATLAS poses absolutely no threat to Earth. Its closest approach will be approximately 1.8 AU (about 170 million miles / 270 million kilometers) from our planet. [NASA]

Latest News & Articles

The Anti-Tail of 3I/ATLAS Turned to a Tail NEW

Avi Loeb / Medium

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A Sunward Jet from 3I/ATLAS Imaged by the Two-Meter Twin Telescope

Avi Loeb / Medium

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ESA's ExoMars and Mars Express observe comet 3I/ATLAS

European Space Agency

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These robots on Mars and Jupiter are capturing images of comet 3I/ATLAS

BBC Sky at Night Magazine

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New Images of Nickel and Cyanide Around 3I/ATLAS from the Keck Telescope

Avi Loeb / Medium

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Comet or alien spaceship? An astrophysicist explains what we know about interstellar traveler 3I/Atlas

Northeastern University

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Interstellar comet 3I/ATLAS is losing water 'like a fire hose'

Live Science

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Swift's UV Telescope Reveals Water in Interstellar Comet 3I/ATLAS

NASA Space News

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Astronomers catch rare glimpse of interstellar comet 3I/ATLAS

ABC News

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European Mars orbiter spies interstellar comet 3I/ATLAS

Space.com

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Interstellar comet 3I/ATLAS carries water across the stars

Earth.com

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Interstellar comet passing by Mars seen in rare images

CBS News

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Official Resources & Links

Official Space Agencies

NASA

Official NASA Science page for 3I/ATLAS

Visit NASA Page →

ESA

European Space Agency FAQ and observations

Visit ESA FAQ →

ESA - ExoMars Observations

ExoMars and Mars Express observation details

View Observations →

Wikipedia

Comprehensive encyclopedia entry on 3I/ATLAS

Read on Wikipedia →

Astro Photons

The Third Interstellar Visitor Explained

Learn More →

Data Sources & API

Real-Time Data Sources

All real-time orbital data and statistics displayed on this website are calculated using official data from:

  • JPL Horizons System - NASA's Jet Propulsion Laboratory provides highly accurate ephemeris data for solar system objects. Our calculations are based on orbital elements from this system.
    → Visit JPL Horizons System
    → API Documentation
  • Minor Planet Center (MPC) - The International Astronomical Union's clearinghouse for observations of asteroids, comets, and natural satellites.
    → Visit Minor Planet Center
  • TheSkyLive.com - Aggregates real-time astronomical data from JPL Horizons and MPC for visualization.
    → 3I/ATLAS Live Tracker

Data Update Frequency: Real-time statistics are recalculated every 5 minutes based on current date/time and latest orbital elements. Historical uptime of data sources exceeds 99.9%.

Fascinating Facts

1st

First interstellar object detected with water by NASA's Swift telescope

3rd

Third confirmed interstellar object ever discovered (after 1I/ʻOumuamua and 2I/Borisov)

6.14

Highest orbital eccentricity of any known interstellar object

Older

Potentially older than our Solar System (up to 14 billion years old)