Image courtesy NASA.
The best thing about Christmas are the presents! And if it hadn't been for that blazing star guiding the three magi to baby Jesus, laden with gold, frankincense and myrrh, then we might not have that present giving tradition at all.
So for Door #5 of the Plus Advent calendar we turn our gaze to the stars and muse on the biggest mysteries of the Universe. Find out what happened before the Big Bang, whether we will one day be able to travel through time, whether those mysterious constants of nature really are constant, how gravity works, and unravel the secrets of dark matter and dark energy.
You can also find out what the greatest star gazers of them all, the Hubble Space Telescope, has discovered, whether there's life on distant planets, why the Universe might just be an illusion, and why a single number holds the key to it all.