Nature: An Anglo-Saxon historical text may shed light on a mysterious radiation spike recorded in Japanese cedar tree rings in AD 774 or 775, writes Richard Lovett for Nature. The connection was made by a biochemistry undergraduate at the University of California, Santa Cruz. After hearing about a team of researchers in Japan who had found the odd spike, Jonathon Allen did “a quick Google search.” In the eighth-century pages of the Anglo-Saxon Chronicle, whose online version is part of Yale University’s Avalon Project, he found a reference to a “red crucifix” that appeared in the sky “after sunset.” In a Nature Correspondence, Allen proposes that the phenomenon could have been a supernova explosion that created a burst of high-energy radiation, which struck Earth’s upper atmosphere and was recorded in the Japanese tree rings.
The finding that the Saturnian moon may host layers of icy slush instead of a global ocean could change how planetary scientists think about other icy moons as well.
Modeling the shapes of tree branches, neurons, and blood vessels is a thorny problem, but researchers have just discovered that much of the math has already been done.
January 29, 2026 12:52 PM
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