President Obama commended the progress of African-Americans in a speech on the 100th anniversary of the NAACP, but said there was still much work to be done.

Apes laugh similar to humans, according to new research exploring the evolution of laughter. James Williams takes a look at the video.

New pictures of never-before-seen parts of Mercury taken by NASA's Messenger spacecraft are revealing surprises about the solar system's innermost planet. Usually the deepest craters are the biggest, but on Mercury there are two craters right next to each other that are about the same size even though one is four times deeper than the other. What's going on? Mercury_craters_4 The shallow crater basin, which is about the size of the greater Washington, D.C.

Since his record-breaking performance at the Beijing Olympics Michael Phelps has been a man in demand. And this week at a special Walt Disney World Parade in his honour he got to meet one of America's most iconic and recognisable stars - Mickey Mouse.