Get ready to witness a celestial wonder in 2026! Mark your calendars for the appearance of interstellar comet 3I/ATLAS, a rare and extraordinary visitor from beyond our solar system. This comet, discovered in 2025, is only the third of its kind ever identified, making it a truly special event for astronomers and sky enthusiasts alike.
3I/ATLAS is a free-roaming comet, not gravitationally tied to any star, and it's been on a journey through the vastness of space. When it was first spotted by the Asteroid Terrestrial-impact Last Alert System (ATLAS) survey in Chile on July 1, 2025, it was a mere 670 million kilometers from the Sun, technically within our inner Solar System. But its closest approach to Earth, on December 19, 2025, brought it a bit closer, at 270 million kilometers away.
This comet has an intriguing history. Scientists believe it originated from a region of the Milky Way galaxy that is home to older stars, and it may be over 7 billion years old, predating our Solar System itself! That's a mind-boggling thought, isn't it?
However, spotting this comet will be a challenge due to its low brightness. On January 1, 2026, it's expected to have a magnitude of +15.6, which is best observed with imaging setups. While it might be faint, smaller smart telescopes should be able to capture its beauty. As it travels westward towards Cancer, it will be near the bright star Regulus in late December and early January.
Here's a helpful tip for skywatchers: On January 1, 2026, comet 3I/ATLAS will be positioned approximately 2.5 degrees north of Omicron Leonis, a star with a magnitude of +3.5, and will be around 20 degrees above the eastern horizon at 22:00 UT. It will reach an altitude of 52 degrees when it's due south at 03:00 UT. As it moves along, it will pass just under 4 degrees north of M67, a cluster of stars with a magnitude of +6.9, on the nights of January 11-13, potentially reaching a magnitude of +16.0.
Later in the month, on January 16, it will be at a magnitude of +16.3 and will pass 3.5 degrees south of M44. Towards the end of the month, it will be in the vicinity of Jupiter. If you're an avid stargazer or photographer, this is your chance to capture the beauty of 3I/ATLAS. Share your sightings and photos by emailing contactus@skyatnightmagazine.com, and let's celebrate this extraordinary interstellar visitor together!
