‘Millennium Falcon’ Comet Sprouts Icy Wings as It Loops around the Sun

Comet 12P/Pons-Brooks, headed for its closest encounter with the sun next year, has started to heat up, leading to a cinematic outburst of icy volcanism

A long exposure of a comet.

Comet 12P/Pons-Brooks is observed in a long exposure image that was taken days after its initial outburst.

Somebody hit the warp speed button, judging from the icy wings astronomers have spotted surrounding an approaching comet.

Comet 12P/Pons-Brooks, which has been likened to the Millennium Falcon of Star Wars fame by one astronomy website for its new look, is now inbound on a fast pass by the sun. It’s one of the brightest known Halley–like comets, which are icy rocks that take 20 to 200 years to orbit the sun and do so along a steeply inclined path relative to the rest of the solar system. On July 20 astronomers worldwide spotted its outburst when the comet brightened 100-fold, making it visible as a horseshoe-shaped aura in backyard telescopes. The outburst may result from a rare case of icy volcanism on a comet—uncorked by solar heating of volatile gases trapped under cometary crusts. Sunlight reflecting off the tossed-up material on the comet’s surface is what causes the brightening.

“Comets are known to be unpredictable,” says astronomer Gianluca Masi of the Virtual Telescope Project, which is a network of worldwide robotic telescopes. “A few of them are famous just for these outbursts.” For instance, in 2021 Comet 29P/Schwassmann-Wachmann erupted four times back-to-back in such a spectacular show that some astronomers referred to it as a “super outburst.”


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Masi speculates Comet Pons-Brooks’s horseshoe shape may result from shadows cast by the dusty “coma” swathing the object after the outburst. “This is not happening every night, so these are precious opportunities,” Masi adds, referring to the fact that astronomers can learn more about these cosmic snowballs and our own space neighborhood. Made of dust, rock and ice, comets are the frozen leftovers from the formation of our solar system.

The comet’s outburst has tossed perhaps 10 billion kilograms of dust and ice into space, which is “fairly large,” says astronomer Carrie Holt of the University of Maryland. Although outbursts have been spotted from the comet by astronomers for centuries, she called the shape of its latest one, “quite peculiar,” and said more observations as it draws closer to the sun should help explain its unusual horns.

Comet Pons-Brooks circles the sun once every 71 years, and its closest solar approach will be next year. It will come nearest to Earth in June 2024, when it will pass some 144 million miles from our blue dot. That should make it faintly visible to the naked eye at night. Right now the comet is still beyond the orbit of Mars. That means it will get hotter as it plunges closer to the sun. “Perhaps we will see more fireworks,” Masi says.

Dan Vergano is a senior Opinion Editor at Scientific American since 2023. He was previously a science reporter and editor at Grid News, BuzzFeed News,National Geographic, and USA Today (where he was the science reporter for 14 years). He wrote a weekly science column, "Science Snapshots" for USA Today for seven years, and has written freelance reports for the Washington Post, Men's Health, Science, New Scientist, Science News, Air &Space Smithsonian, and others.

Starting in the 1990's, Vergano has become best known for pioneering new approaches to investigative science journalism, in reporting ranging from State Department cover-ups of "Havana Syndrome" findings to the peer reviews of the "Arsenic-Life" fiasco to the botched HHS investigation of the CDC's failed coronavirus vaccine. He was a leading national reporter in coverage of climate change in the 2000's, of the overdose crisis in the 2010's, and coronavirus vaccines in the pandemic. He broke the news that space shuttles had suffered excessive heating due to foam strikes before the Columbia disaster in 2003, and published a feature report on the suspected Anthrax killer in 2004, a year before the FBI identified the suspect.

Dan is the chair of the New Horizons committee for the Council for the Advancement of Science Writing, and a journalism award judge for both the American Association for the Advancement of Science and the U.S. National Academies of Science, Engineering and Medicine. He taught journalism as an adjunct professor for New York University from 2012 to 2014, and was a 2007-08 Nieman Fellow at Harvard, where he studied the intersection of politics and science. He has won the 2011 Gene S. Stuart Award by the Society for American Archeology, 2006 David Perlman Award for Deadline Science journalism by the American Geophysical Union and was a Finalist for 2001 Missouri Lifestyle Journalism award.

Vergano has a B.S. in Aerospace Engineering from Penn State and an M.A. in Science, Technology and Public Policy from George Washington University. He worked as a space policy analyst for a federal-funded research and development center prior to starting his reporting career.

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