Interstellar comet 3I/ATLAS reaches perihelion 204 million km from the Sun this Wednesday

Comet 3I/ATLAS, the third confirmed interstellar object, reaches perihelion on October 29. The closest point to the Sun occurs at 1.36 astronomical units, equivalent to 204 million kilometers. Discovered in July 2025, the celestial body originates outside the Solar System.

Astronomers monitor the event at 8:47 Brasilia time. The distance prevents total fragmentation of the nucleus. Solar heat activates the sublimation of ice, forming coma and tail.

• Perihelion scheduled for October 29;
• Distance of 204 million km from the Sun;
• Exact time: 8:47 in Brasilia.

Discovery and origin

Comet 3I/ATLAS was identified in images from the CCOR-1 coronagraph on the GOES-19 satellite. An amateur astronomer processed daily data behind the Sun.

The origin can be traced back to an unknown star in the Milky Way. The chemical composition offers data on planetary formation in distant systems.

Effects of perihelion

The maximum heat transforms ice into gas in the core. Released dust creates structures visible from Earth.

The distance greater than Mercury’s orbit reduces risks. Minimal cracks may occur in fragile areas.

The brightness increases during the step. Intense activity highlights chemical elements.

Future trajectory

After perihelion, the comet begins to move away from the Sun. Visibility returns on November 3 in the morning sky.

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The object appears in the constellation of Virgo until November 17. Position rises 3 degrees every day.

Close approaches

The Earth receives passage on December 19 at 269 million kilometers. Jupiter enters orbit in March 2026 at 54 million km.

The planet’s gravity slightly alters the trajectory. Brightness decreases until the end of March 2026.

Practical observation

Telescopes capture the comet before dawn. Position at 9 degrees above the eastern horizon.

Animations simulate movement through the Solar System. JPL data updates orbital parameters.

The nucleus remains intact after perihelion. Studies confirm structural stability. Composition includes rare metals. Observatories in Namibia record ice jets. Established platforms provide accurate predictions.

Orbital data

Parameters indicate hyperbolic orbit. Speed exceeds solar escape.

• Astronomical unit: 149.6 million km;
• Perihelion: 1.36 AU;
• Tyerra Approach: 1.80 UA;
• Influence Jupiter: 0.36 UA. <>