Comet C/2024 G3 (ATLAS) zipped close to the sun on Jan. 13 and put on quite a show for NASA’s Solar and Heliospheric Observatory spacecraft. SOHO images show the comet swooping across the view with a bright tail like the plumage of an exotic bird. NASA shared a dramatic video of the comet’s dance on Jan. 22.
ATLAS G3 earned the nickname of the “New Year comet” thanks to the timing of its nearness to Earth and the potential to see it in the sky primarily from the Southern Hemisphere. A comet visible from Earth is always a cause for excitement. They’re targets for astrophotographers, but it’s even more thrilling when skywatchers can see them with the naked eye. SOHO, however, had a much different view of the comet than anyone on the ground on Earth.
SOHO Sees A Comet
SOHO’s Large Angle Spectrometric Coronagraph instrument suite captured the footage of ATLAS G3. “I think it’s the prettiest comet I’ve ever seen in the LASCO images—and I’ve seen about 5,200 of them!” said astrophysicist Karl Battams of the Naval Research Laboratory. Battams is LASCO’s principal investigator. LASCO blocks the solar disk so it can observe what’s happening around the sun without the sun’s light drowning out the data. The small white circle in the images indicates the location of the sun’s body.
SOHO was launched in 1995 and is a joint mission of NASA and the European Space Agency.
SOHO tracked the comet from Jan. 11 to Jan. 15. The comet reached perihelion, its closest point to the sun, on Jan. 13. At that point, it was just 8 million miles from the sun. That might sound like a lot of miles, but it’s very snuggly for a sun encounter. “When bright comets like this one pass close to the sun, their tails often react to fluctuations in the solar wind, a stream of particles and energy constantly flowing off the sun,” NASA said. “Heliophysicists can study the reaction of the tails to better understand the sun’s effects on its neighborhood and on comets passing by.”
Studying The Comet’s Tail
The brightness of the comet’s head affected LASCO’s images, creating what NASA described as artificial streaks. Another spacecraft, NASA’s Solar Terrestrial Relations Observatory (STEREO) also caught sight of ATLAS G3. STEREO’s observations highlight the streaky appearance of the comet’s tail. A processed image from STEREO makes the tail really pop. “I think the remarkable thing is the heavily striated tail,” Battams said. “There’s a combination of processes going on that will take scientists some time to figure out.”
Earth dwellers and spacecraft got to enjoy the visit from ATLAS G3. Astronauts on the International Space Station got in on the fun earlier in the month. NASA’s Don Pettit shared a photo of the comet on Jan. 10, showing the bright trail stretching out above the curvature of Earth. Pettit called the view “totally amazing.”
Comets orbit the sun and are made mostly of ice with some dust and rocks in the mix. The tail is a streamer of gas and dust. They’re like cosmic snowballs shedding material as they go. Not every comet survives perihelion, but scientists are still assessing ATLAS G3 and its prospects. It’s not easy being a snowball near the sun.
