NASA scientists will go live at 1 p.m. Eastern time on Friday to discuss Scott Kelly's record-breaking year in space. At 342 days, Kelly's mission is the longest ever undertaken by a U.S. astronaut. The purpose of the mission was to test the effects of longterm spaceflight in preparation for longer missions to Mars and the worlds beyond.

Kelly's identical twin, retired astronaut Mark Kelly, will also be present at the 1 p.m. news briefing. The earthbound twin served as a kind of experimental control, allowing scientists to pinpoint which physical and mental changes might have been space related. You can read more about that here.

A 2 p.m. briefing with Scott Kelly himself will follow. This is the spaceman's first big appearance since he arrived back in Houston early Thursday morning.

You can ask questions for either briefing by tweeting #askNASA. You can also jump into Reddit's Friday morning AMA on the subject, where NASA scientists will be answering questions until they get sick of us.

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