It’s hot in the the tail of the Quadrantids meteor shower, another spectacle in the sky is about to arrive: the comet Atlas C/2024 G3, which will reach perihelion—the point of its closest rotation to the sun—on January 13. On the same day, we will also come to see it at its closest point to Earth, and it could be the brightest comet of 2025, during a year when no other comet will be visible to the naked eye. Here’s everything you need to know.
IC/2024 G3 was discovered on April 5, 2024, by the Asteroid Terrestrial-Impact Last Alert System (Atlas)—an array of telescopes that scan space for asteroids that might hit Earth. The comet originates from the Oort Cloud, a distant region at the outer edges of the solar system that is believed to contain remnants of the material that formed the planets of the solar system.
When comet C/2024 G3 reaches perihelion, it will come within 13.5 million kilometers of the sun—in context, Mercury, the closest planet to the sun, orbits the star at a distance of 47 million kilometers. According to the latest figures reported by the Planetary Society, C/2024 G3 can reach a magnitude of -4.5, which is about the same as Venus, and may be visible to the naked eye for people located in the southern hemisphere.
The comet’s unusually close trip to the sun, however, raises questions about whether it will survive. Its orbit suggests that it is an old comet, and that this is not its first trip around the sun. In fact, its last approach is estimated to be about 160,000 years ago, which means it may have already survived a near-death experience. “It’s going to be very hot and it may not survive,” said Nick James, director of the comet division of the British Astronomical Association. “But if it does, it would be an impressive sight in the evening sky from the southern hemisphere after perihelion.”
How to Observe a Comet
If it survives unscathed, the comet will be visible in the southern hemisphere to the west just after sunset on January 13. The comet’s structure makes it difficult to see for those in the northern hemisphere—it will appear very low in the sky shortly after. Sunset or before sunrise, but may be eclipsed by twilight.
The comet’s proximity to the sun means that viewing it can be dangerous, and James says C/2024 G3 “should only be viewed if you are an experienced observer.” Looking directly into the sun without protective equipment can cause permanent eye damage.
There will also be interference from the moonlight, which will be waning, making viewing more difficult. Viewing the comet with the naked eye in the southern hemisphere may be possible, but may require binoculars or a telescope.
Those who do not want to miss the show can follow the comet in images from the Solar and Heliospheric Observatory’s Lasco C3 coronagraph, or consult the IAU Minor Planet Center or the Comet OBServation (COBS) website.
This story appeared first WIRED Italia and translated from the Italian.