This is an alien world and anything could happen. Cautiously we explore, taking care not to get lost.

In the silence we hear a distant sound! A sort of "boom, boom, boom" sound, like underground machinery. There could be intelligent life here! But what happens if they see our space craft?

Should we RUN? Get back to the space craft as fast as we can? Or should we move backwards as slowly and carefully as possible? Or do something else?