Should humans colonise Mars? Is there life in the Universe? Science continually seeks to answer big questions - but it takes a lot of research and communication to come to a consensus. Why not host a debate and try it yourself?

Have you noticed that the Moon doesn't always look the same. Sometimes we can see the full face of the Moon and it becomes the brightest object in the night sky. At other times, it appears as a just small sliver in the sky.

You have probably seen the Moon in the sky but have you ever studied it in detail? 

You have likely heard about the Universe expanding. Or that redshift can tell us about the movements of galaxies. Both are difficult ideas to imagine and understand.

The Moon is the brightest object in the night sky when its whole face is showing. This only happens at full Moon. So why isn't it always a full Moon?