In the first weeks of 2016, 29 sperm whales were found stranded and dead off the coasts of Britain, France, the Netherlands, and Germany, the BBC reports.
The whales had been generally healthy, and scientists were confounded as to what had caused them to enter the dangerously shallow waters of the North Sea.
Now a study published last month in the International Journal of Astrobiology has a possible answer: Two massive solar storms in the final days of 2015 screwed with Earth's magnetic field and affected the sperm whales' ability to navigate.
Or, as Gizmodo puts it: "The Sun could have broken the whales' GPS." Researchers say sperm whales use Earth's magnetic field to navigate. They say the field usually creates a "geomagnetic mountain chain" that prevents the whales from entering the North Sea.
But the solar storms could have caused that mountain chain to disappear and sent the whales in the wrong direction. "They do not realize that the Sun is changing the geomagnetic environment for a short time," study author Klaus Henrich Vanselow says.
Researchers say measuring stations noticed changes in Earth's magnetic field from solar storms just prior to the stranded whales appearing. Vanselow's research will be very hard to prove, but other scientists say it's a "valid hypothesis" and "credible theory." (These whales are rarely seen, but scientists managed to spot two.)
This article originally appeared on Newser: New Study Claims the Sun May Have Caused 29 Whales to Die