NASA spacecraft capture rapid brightening of interstellar comet 3I/ATLAS during sunward journey

Comet 3I/ATLAS is currently undergoing rapid brightening as it approaches perihelion, its closest point to the Sun. The perihelion event is set for October 29, 2023. This remarkable comet has garnered attention from both researchers and amateur astronomers, despite being obscured from Earth’s view as it swings behind the Sun.

Tracking Comet 3I/ATLAS

Amateur astronomer Worachate Boonplod successfully tracked the comet with the GOES-19 weather satellite. This satellite, operated by the National Oceanic and Atmospheric Administration (NOAA), employs the CCOR-1 instrument to monitor solar conditions regularly.

• Date of discovery: The comet was identified in July 2023.
• Brightness: As of October 18, its brightness was comparable to nearby stars with a magnitude of approximately 11.
• Visibility: Boonplod confirmed the comet’s visibility from the satellite until October 24.

Satellite Observations

In addition to GOES-19, several other missions are observing 3I/ATLAS:

• NASA’s PUNCH mission, comprising four small satellites focused on solar studies.
• NASA and ESA’s Solar and Heliospheric Observatory (SOHO), located nearly 1 million miles (1.5 million kilometers) from Earth.

These instruments are crucial for tracking the comet’s movement and provide valuable insights into its characteristics and behavior.

Rapid Brightening Ahead of Perihelion

Recent studies suggest that 3I/ATLAS is brightening rapidly as it approaches perihelion. Researchers estimate that it could reach a brightness of around magnitude 9 at perihelion. While this is still too dim for the naked eye, it should be visible with quality telescopes.

According to findings published on October 28, the comet appears bluer than the Sun, indicating significant gas emissions contributing to its brightness. As comets approach the Sun, they heat up, causing surface ices to vaporize into gas, which envelops the comet and aids in forming its tail.

Scientific Insights

Comet 3I/ATLAS is notable for traveling at speeds exceeding 130,000 mph (210,000 km/h), making it the fastest known solar system object. It follows a flat trajectory, which contributes to its classification as the third interstellar comet ever documented.

• Age: Some studies suggest that it may be up to 3 billion years older than our 4.6 billion-year-old solar system.
• Size: Hubble Space Telescope data indicates a maximum width of approximately 3.5 miles (5.6 km).

After its passage behind the Sun, the comet is expected to be visible again through Earth-based telescopes by early December 2023. It will make a close approach to Jupiter in March 2026, where it may also be observed by spacecraft near the gas giant.

Conclusion

As comet 3I/ATLAS continues its journey through our solar system, ongoing observations and studies will enhance our understanding of this unique interstellar traveler. Its rapid brightening during its sunward journey is a fascinating subject for both enthusiasts and scientists alike.