One of our galactic neighbors, the tiny Segue 1, could be among the first galaxies ever to take shape—and it may present an opportunity for scientists to examine our universe as an infant. Segue 1's chemical composition suggests it stopped evolving some 13 billion years ago, Scientific American reports; in fact, researchers say, it's the "least chemically evolved galaxy known." Stars contain heavier and heavier elements with each generation, but the stars in Segue 1 have hardly any heavy stuff—they're made mostly of just hydrogen and helium.
"Segue 1 is so ridiculously metal-poor that we suspect at least a couple of the stars are direct descendants of the first stars ever to blow up in the universe," says the co-author of a study that investigated six of the galaxy's brightest stars. The research suggests that Segue 1 rapidly formed one batch of stars before halting the process permanently. Experts are trying to figure out why, and further study could help explain both how galaxies begin evolving and how they stop, the magazine reports.