Two NASA astronauts are finally back on Earth after an unexpected nine-month stay in space. What kept them up there so long? Meanwhile scientists have discovered that gray seals have a built-in oxygen gauge that helps them hold their breath for more than an hour. And in the Antarctic, researchers found that penguin poop seriously stresses out krill. Catch up on these stories and more in our Monday news roundup.

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After 286 Days in Space, NASA Astronauts Return to Earth with a Splash 

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Science Quickly is produced by Rachel Feltman, Fonda Mwangi, Kelso Harper, Naeem Amarsy and Jeff DelViscio. This episode was edited by Alex Sugiura. Shayna Posses and Aaron Shattuck fact-check our show. Our theme music was composed by Dominic Smith.

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