Anxiety abounds at NASA as Mars landing day arrives

A NASA spacecraft's six-month journey to Mars neared its dramatic grand finale Monday in what scientists and engineers hoped would be a soft precision landing on flat red plains.

What happened before the Big Bang?

A team of scientists has proposed a powerful new test for inflation, the theory that the universe dramatically expanded in size in a fleeting fraction of a second right after the Big Bang. Their goal is to give insight into ...

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