The day a weasel shut down CERN

...and a zoo of similar offenders that have tinkered with major science projects.

By Victoria Jaggard
Published 16 Jan 2019, 10:57 GMT
A common weasel peers out from the undergrowth.
Photograph by Flip de Nooyer, Minden Pictures, National Geographic Creative

Unlocking the secrets of the universe can be a massive undertaking. Just this week, plans were announced for a new 100km particle accelerator to be built next to the Large Hadron Collider run by CERN in Geneva, Switzerland - the huge underground machine where scientists discovered the Higgs boson in 2012.

Some may be asking if there will be any advanced animal proofing included. As researchers have learned, it only takes a single furry or winged beast to throw our cosmic endeavors right off the rails.

In April 2016 the world's most powerful particle accelerator came to an abrupt halt due to a power outage. 

According to an internal status update, the cause of the LHC’s electrical glitch was a fouine, French for “weasel” or “marten.” The mischievous mammal seemed to have chewed into one of the collider’s electrical transformers, triggering a short circuit. Unfortunately for the animal, it did not survive its shocking adventures. A second outage was caused the following November by a stone marten. The corpse of this animal later became a museum exhibit.

“I can confirm that the Large Hadron Collider is on standby mode, following technical issues in the last 24 hours, including a power cut due to the passage of a weasel,” CERN spokesperson Arnaud Marsollier said in an email at the time.

“The concerned part of the LHC stopped immediately and safely, though some connections were slightly damaged due to an electrical arc,” he added. 

While it’s unclear why small mammals might munch on electrical gear, it’s definitely not uncommon, says Roland Kays, head of the Biodiversity Research Lab at the North Carolina Museum of Natural Sciences.

The CMS detector in the Large Hadron Collider helped scientists find the Higgs boson.
Photograph by CERN

“Martens chew on car wires all the time in Europe, it’s a pretty big problem actually,” he said in an email, adding that there is “quite a bit of engineering now going into reducing the problem.”

The incident is definitely not the first time animals have tinkered with some of our biggest science projects. Here are four more wild encounters between beasts and machines.

Original Computer Bug

Techy types have been calling weird engineering problems “bugs” since the 1800s. Perhaps the most famous is the unfortunate moth that got stuck in the Harvard Mark II computer in 1947. Engineers servicing the hulking machine were so amused they taped the dead moth into a logbook with the phrase “first actual case of bug being found.” The book and the moth are now in the collections of the Smithsonian’s National Museum of American History.

Physicists Robert W. Wilson (right) and Arno Penzias stand in front of the radio antenna they used to discover the echo of the big bang.
Photograph by Associated Press

Cosmic Pigeons

In the 1960s, physicists Arno Penzias and Robert Wilson were trying to use a 20-foot antenna at Bell Labs in New Jersey to map radio signals in the spaces between galaxies. Despite taking many steps to weed out background noise, the pair kept hearing a uniform sound at a particular microwave wavelength. Their primary suspect for the static: pigeons that had taken up roost inside the antenna.

The duo diligently ousted their avian interlopers and spent hours cleaning up pigeon poop. Weirdly, the static was still there, and that turned out to be good news. The physicists eventually discovered that they were listening to the cosmic microwave background, an echo of the big bang that permeates the universe.

The Tevatron particle accelerator in Batavia, Illinois
Photograph by Epa

Raccoon Rabble

The LHC isn’t the only particle accelerator to have wildlife troubles. A 2006 status update from the Tevatron, a now defunct collider at Fermilab in Illinois, notes that on May 30, the facility had to battle a “raccoon attack.” Shortly after midnight, according to the report, the masked invaders tried to stake out turf in the accelerator and the division headquarters, but they were repelled by the staff.

“No raccoons were either injured or captured during these encounters,” the report states.

A closeup of the space shuttle's external fuel tank shows the free-tailed bat.
Photograph by NASA

Space Bat

NASA is also no stranger to animal hiccups. The launch complex at Kennedy Space Center in Florida shares the area with the Merritt Island National Wildlife Refuge, home to crocodiles, manatees, and other local wildlife. But it was a free-tailed bat that made headlines in 2009, when it took an inadvertent ride on the space shuttle Discovery.

The bat was spotted clinging to the shuttle’s orange fuel tank shortly before its scheduled liftoff. The animal appeared to have a broken wing, which may be why it clung to the spacecraft even as it roared into the sky.

Follow Victoria Jaggard on Twitter.

An earlier version of this article originally appeared on 


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