Mercury would have the worst Airbnb reviews due to extreme temperature swings, total lack of amenities, incredibly long days, ...

But of these planets, which is nearest to the sun? Mercury is a strange little world. There are some craters on its surface that never see sunlight. It also has the most extreme temperatures of ...

Feb. 18 marks the 95th anniversary of the discovery of our outermost planet-not-planet. Here's what to know about the short ...