Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. Today is Shannon Lucid's first day on Planet Earth in six months. Her stay aboard Russia's Mir Space Station was of record length - the longest stay of any American in space ever. During her time in orbit around the Earth, Lucid, a biochemist , did many things including experiments on the effect of weightlessness on the human body. Pictured above , Lucid greets the astronaut that will replace her on Mir , John Blaha .
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