So is there life on Mars?
It sounds like a simple question - and probably seems like it might be simple to answer. Just go there and… look. Right?
Nope. The search for life on Mars is not as simple as looking for something that looks a bit like a frog -- sorry, UFO fans.
In fact working out if there has ever been - or if there might even still be - life on or within Mars is incredibly difficult, not least because the planet is both further away, and more hostile to most forms of life we understand, than is commonly realised.
As a result of all of these factors, it is incredibly hard to summarise the extent of research into Martian organics and life in just a few words. But here are some of the basics that we know so far.