spiral galaxy UGC 9391

UNRULY UNIVERSE  Different methods for measuring the universe’s expansion rate disagree. To make one such measurement, scientists observed Cepheid variable stars and a type 1a supernova in the spiral galaxy UGC 9391 (shown), located 130 million light-years away in the constellation Draco.

air bubbles in a rock

NOT-SO-FRESH AIR  Ancient air embedded inside rock salt for 815 million years suggests that oxygen was already abundant when the first animals appeared. The microscopic air bubbles were trapped inside rectangular inclusions (one circled in red) in the rock.

Cow killer ant

OUCH  Dasymutilla occidentalis, commonly known as the cow killer ant based on its painful sting, is actually a flightless wasp. The wasp and other venomous critters are the subjects of two new books.

Alzheimer’s plaques in human brain

PLAQUE FIGHTER  A long dose of antibiotics reduced Alzheimer’s-related plaques (shown here in a human brain) in the brains of mice, results that suggest gut bacteria can influence the disease. 



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