Two women made allegations against the astrophysicist and "Cosmos" host in a newly published report.
A professor broke down why Trump's wild brag can't possibly be true.
The famed astrophysicist looks at the evidence.
NASA has revealed new details about its hotly anticipated mission to fly a space probe into the sun’s atmosphere to learn more about solar radiation.
The big question: Did they leave artifacts behind for us to find?
He started writing it just weeks after Britain entered WWII.