NASA’s observations recently revealed significant brightening of comet 3I/ATLAS as it nears its closest approach to the Sun. The comet, which has garnered attention since its discovery in July, is set to reach perihelion on October 29, 2023.
Key Observations of Comet 3I/ATLAS
Amateur astronomer Worachate Boonplod has actively monitored comet 3I/ATLAS utilizing the GOES-19 weather satellite’s data. This satellite, known for its solar observation capabilities, has provided crucial insights into the comet’s brightness and trajectory.
- The comet was detected by Boonplod on October 18, 2023.
- It was visible until October 24, with an estimated brightness of approximately magnitude 11.
- This brightness level is comparable to nearby stars.
Multiple NASA missions are also tracking the comet, including the Polarimeter to Unify the Corona Heliosphere (PUNCH) and the Solar and Heliospheric Observatory (SOHO). The SOHO spacecraft has been monitoring the comet until October 26.
Characteristics of 3I/ATLAS
Recent studies indicate that comet 3I/ATLAS has been experiencing rapid brightening as it approaches perihelion. According to findings posted on arXiv, the comet’s brightness is expected to reach about magnitude 9 at its closest point to the Sun. This level of brightness would make it visible through good backyard telescopes but still not to the naked eye.
The study revealed that 3I/ATLAS appears distinctly bluer than the Sun. This change is attributed to gas emissions from the comet, which contribute to its brightness as it heats up and sublimates ices into gas, forming a tail.
Unique Aspects of Comet 3I/ATLAS
3I/ATLAS is only the third known interstellar comet, traveling at an unprecedented speed of over 130,000 mph (210,000 km/h). It follows a remarkably straight trajectory through the solar system, and researchers consider it potentially the oldest comet ever observed, with age estimates around 3 billion years, which is notably older than our solar system’s 4.6 billion years.
- The comet may also be the largest interstellar object detected, with a suspected width of about 3.5 miles (5.6 km).
- 3I/ATLAS will become visible again to Earth-based telescopes by early December 2023.
- It is expected to make a close approach to Jupiter in March 2026, which may also provide additional observational opportunities.
While the swift passage of 3I/ATLAS raises speculation about extraterrestrial origins, astronomers maintain that it is a natural celestial body from a distant star system.
As comet 3I/ATLAS continues its journey, observations from both ground-based and space-based telescopes will remain crucial in uncovering its secrets.
