Oct 03, 2021 I Paul Seaburn

Mysterious Flashing Comet Defies the Rules of Cometary Behavior

Comets are a favorite space rock of amateur astronomers for many reasons – they’re often seen without a telescope, their tails tale them easy to fins, some return on a regular scale and a few end up in rock songs. However, they’re mostly just icy rock balls and don’t do anything special – except for Comet 29P/Schwassmann–Wachmann, better known as Comet 29P, the flashing comet. The what? What’s making it flash?

29P orbit 570x321
29P Schwassmann Wachmann orbit (NASA)

“Some are calling this a super outburst. This requires an immense amount of energy. We don’t know. And that’s what makes it so interesting.”

Dr. Maria Womack, an astrophysicist at the National Science Foundation, told The New York Times that the 37-mile-wide 29P comet doesn’t act like the ice ball it is – it is constantly blasting off gas and dust as it orbits the Sun every 14.6 years in a nearly circular orbit … a real oddity in our solar system. Discovered in 1927 by German astronomers Arnold Schwassmann and Arno Arthur Wachmann, it has an unusual brightness range between 12 and 16 magnitude. However, when it hits 16, it occasionally goes superbright and can reach 21 magnitude. 29P averages an amazing 7.3 bursts per year but their timing is unpredictable as is their brightness, so what happened last week was unexpected and unbelievable … 29P emitted four consecutive outbursts.

  • Current Status and Latest Observations:
  • STOP PRESS - Fourth outburst on 2021 09 27.6+/-0.2 almost 9 times greater intensity than the first two events !!!!
  • STOP PRESS - Third outburst on 2021 09 27.0 almost 5 times greater intensity than the former two events. Time between each pair of outbursts ~20 h
  • LATEST: An outburst of about 2.5 mag amplitude appears to have occurred on 2021 September 25.34 +/-0.005 followed about 20 hours later by another outburst of similar intensity

Richard Miles, director of the asteroids and remote planets section of the British Astronomical Association, is the project lead on the MISSION 29P website, which keeps track of 29P activity and issued those news bursts as the comet bursts happened. According to Sky and Telescope, Miles thinks 29P’s first massive outburst triggered the next and so on until they stopped at four. No other comet in the solar systems flares with this frequency and intensity.

29P Schwassmann Wachmann
29P Schwassmann Wachmann (NASA)

However, no astronomer can answer the big question. They speculate the flares could be caused by carbon monoxide heating up and erupting into space – a process called cryovolcanism where sunlight weakens 29P’s crust, allowing cryomagma made up of carbon monoxide and other slushy ices to vigorously bubble out like champagne from a shaken bottle. Or the flares could be caused by a cometary landslide or even a cometary quake causing a piece to break off. Dr. Kacper Wierzchoś, an astronomer at the University of Arizona, had an observation that we all can relate to.

“Who knows?”

That means they’ll keep on watching and reporting on the MISSION 29P website.

The Flashing Comets would be a great name for a band … as long as the social media algorithms don’t censor it.

Paul Seaburn

Paul Seaburn is the editor at Mysterious Universe and its most prolific writer. He’s written for TV shows such as "The Tonight Show", "Politically Incorrect" and an award-winning children’s program. He's been published in “The New York Times" and "Huffington Post” and has co-authored numerous collections of trivia, puzzles and humor. His “What in the World!” podcast is a fun look at the latest weird and paranormal news, strange sports stories and odd trivia. Paul likes to add a bit of humor to each MU post he crafts. After all, the mysterious doesn't always have to be serious.

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