Comets are unpredictable, fleeting visitors in our sky, and C/2024 G3 (ATLAS) was no exception.
This January, it graced the southern hemisphere with its glowing tail, formed as ice sublimated near the Sun. Now moving away, signs suggest its nucleus may be breaking apart, making it a race against time to witness this cosmic wonder.
Cosmic Visitors with a Mind of Their Own
“Comets are like cats: they have tails, and they do precisely what they want,” wrote David H. Levy, an amateur astronomer who discovered 23 comets. These celestial wanderers are indeed unpredictable, and their visibility in the sky is never guaranteed.
A Stunning Sight in the Southern Sky
In January, the southern hemisphere was treated to a spectacular sight — comet C/2024 G3 (ATLAS). Captured in a breathtaking image by engineer Juan Beltrán on January 20 at ESO’s Paranal Observatory in Chile, the comet showcased its fleeting beauty. Just last year, another comet made a brief appearance, this time photographed at the European Southern Observatory’s Headquarters in Garching, Germany (see image below). These non-periodic comets are rare visitors, lingering in our skies for only a few weeks. Miss your chance to see one, and you might be waiting thousands of years for its return.
The Science Behind a Comet’s Tail
As comets approach the Sun they warm up, and the ice in them sublimates, meaning it goes directly from solid ice to gas. Dust particles are also released, and the solar wind and radiation push this gas and dust away from the Sun, creating extended tails. Although astronomers can calculate and estimate how long a comet will be visible, sometimes they surprise us, either by disappearing sooner, or by actually surviving their trip near the Sun relatively intact, saving their typical tail of gas and dust.
The Fate of C/2024 G3 (ATLAS)
For C/2024 G3 (ATLAS) that tail may fade quickly. The comet reached perihelion — the point where it is closest to the Sun — on January 13, 2025. At that point, it was only 13 million kilometers (8 million miles) away from our star. But it is now moving away, and there are signs that the nucleus might have fragmented even though the tail is still visible. If you are in the southern hemisphere you can still try to catch it towards the west after sunset; otherwise, check ESO’s webcams!
