'Dr Becky' receives thousands of views on her YouTube channel which answers questions about the universe.
Mark Armstrong talks about his father, and the first ever Moon landing 50 years ago.
Computer scientist Katie Bouman is part of the team behind the first-ever image of a black hole.
SpaceX's capsule has splashed down after a week-long test mission to the International Space Station.
The unmanned commercial test vehicle will splash down in the Atlantic Ocean on Friday afternoon.