The Moon is so familiar we barely look at it, but it is genuinely peculiar, far too large for a planet our size, and we are fairly sure it exists because something the size of Mars hit the young Earth. We look at the evidence for that collision, how the Moon drives our tides, and the argument that without it, Earth might be a much less hospitable place.

You'll come away understanding why the Moon always shows us the same face, why it is slowly drifting away, and what it stabilises about our planet.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: NASA lunar science; Lunar and Planetary Institute; Apollo sample analysis summaries.