US firm Vast is developing spinning space stations with artificial gravity to keep astronauts healthy on deep-space missions and push the search for alien life.

The imaginary constructions of science fiction fill us with awe at their alien vastness. Which have you explored, and what was the most overwhelming?

A top scientist has suggested that aliens may be 'terrified of Earth' not because of humanity, but due to a bizarre cosmic phenomenon known as time dilation, which could leave any interstellar visitor ...