Bright green Comet SWAN falls apart after once-in-a-lifetime appearance in our night sky

Another comet has fascinated skygazers but has already sung its swan song after approaching the Sun.
Comet SWAN (C/2025 F2) was discovered in March with the Solar Wind Anisotropies (SWAN) instrument on Nasa's Solar and Heliospheric Observatory (SOHO) spacecraft, hence why SWAN is in the comet's name.
Since its discovery, hundreds of observations of the comet have been logged into the International Astronomical Union's Minor Planet Center from observatories around the world.
Why The Closest Supermoon Of The Year Will Be Invisible To Earth
Comet SWAN was set to reach perihelion, the closest distance to the Sun, around May 1, raising hopes the possibility of unaided-eye viewing could be on the table later this month.
But recent observations show the comet didn't make it past the final approach.
"It looks like there's not much left of it, and it seems to be just clouded dust at this point that's gradually getting more diffuse and flying apart," said Dr. Qicheng Zhang, a post-doctoral astronomer at Lowell Observatory in Arizona.
Zhang studies comets that get very close to the Sun, known as sun-grazers, such as Comet C/2024 G3 ATLA's approach in January.
Comet SWAN was a smaller comet and Zhang said this is likely the factor that led to its early end.
See It: Lyrid Meteor Shower Peaks In Dazzling Worldwide Display
"The thing with small comets is that they tend to get spun up really easily by just random variations in their outgassing," he said. "When the ice on them starts to sublimate and create gas. It tends to not come out perfectly symmetrically. And that asymmetry starts to like, torque the thing and just spin it up."
As a comet spins up, it starts to fall apart, which is likely what is happening to Comet SWAN now before it ceases to be an active comet.
Comet SWAN has been observed by professional and amateur astronomers worldwide with its notable green coloring. Zhang said this coloring is likely from diatomic carbon.
"Comets have a lot of organic material. When you toss it out into space, you get UV rays from the Sun that hit those complicated organic molecules, which happen to contain a lot of carbon. And when they get broken down, you'll get pieces that contain essentially just two carbon atoms stuck together. And that's essentially just the green that we see in these comets," Zhang said.
The comet's orbital period is 1.4 million years, so even if it survived perihelion, it would be the last chance to see it in our lifetime.
So long, Comet SWAN.Original article source: Bright green Comet SWAN falls apart after once-in-a-lifetime appearance in our night sky

Try Our AI Features

Explore what Daily8 AI can do for you:

Learn with AIFact CheckingText to SpeechAI Summary

Related Articles

Wall Street Journal

5 hours ago

• Wall Street Journal

World's Largest Digital Camera Snaps Its First Photos of the Universe

Cerro Pachón, CHILE—The Vera C. Rubin Observatory on Monday released its first dazzling images of deep space in a preview of the cosmic movie the pioneering probe was built to create. The U.S.-funded observatory, perched in an area of the Chilean Andes known for exceptionally dark skies, is equipped with the world's largest digital camera and a 27.5-foot mirror that can capture light too faint for other telescopes to see.

Newsweek

5 hours ago

• Newsweek

Satellite Image Captures US Volcano 'Ready to Rumble'

Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. An image of Alaska's Iliamna Volcano "ready to rumble" has been captured from space. The image was taken on June 10 by the OLI (Operational Land Imager) on the Landsat 8 satellite, which is operated by NASA and the United States Geological Survey. The volcano saw an increase in seismicity, marked by frequent small earthquakes, around 4:30 a.m. local time on June 15. "This activity is likely not caused by volcanic unrest," the Alaska Volcano Observatory (AVO) said, but is instead caused by avalanches thundering down the volcano's slopes. While it last erupted in 1867, Iliamna still rumbles once every two years and "its murmurs tend not to be signs of volcanic unrest but rather the signature of avalanches large enough to register on nearby seismic and infrasound instruments," NASA explains. The AVO added: "Initially, the earthquake rate was nearly continuous, with several earthquakes per minute, but this has since slowed to a rate of about one earthquake per minute." A NASA satellite image of Alaska's Iliamna Volcano appearing "ready to rumble" days before seismic activity was reported days later. A NASA satellite image of Alaska's Iliamna Volcano appearing "ready to rumble" days before seismic activity was reported days later. NASA Earth Observatory The snow-covered stratovolcano is found on the western side of the lower Cook Inlet of Lake Clark National Park, about 130 miles southwest of Anchorage and 30 miles southwest of the more eruptive Redoubt Volcano. "Although steam plumes occur on its eastern flanks, there has been no historical volcanic activity at Iliamna," notes the AVO. While the AVO did not have enough information, as of June 16, to ascertain the size and location of any slide that may have occurred that day, the recent seismic activity was similar to that caused by the initial slipping between rock and ice that has preceded large avalanches on the volcano in the past. However, the "outcome of the current activity remains uncertain," the AVO says, noting that large ice and rock avalanches on Iliamna in the past have taken place around this time of year. Mostly covered by perennial snow, ice and numerous glaciers radiating from the summit area, large avalanche deposits are observed on Iliamna's flanks, especially down the Umbrella Glacier on its southwest side. Massive slides on the slopes of the volcano can occur from a combination of glacial ice; hydrothermally altered and weakened rock; and volcanic heat. Researchers says the frequency of the large ice and rock avalanches observed at this volcano is unusual but offers a setting for understanding the mechanics and precursors of this type of event. "Iliamna is remote, but similar conditions in more populated ranges around the planet could pose hazards to communities," NASA warned. Do you have a tip on a science story that Newsweek should be covering? Do you have a question about volcanoes? Let us know via science@

CNN

6 hours ago

• CNN

First look: Rubin Observatory's images reveal universe like never before

The Vera C. Rubin Observatory released its first images, showcasing millions of galaxies. The images are also expected to reveal thousands of previously unknown space objects.