I’m amazed by the fact Mars looks a lot like some areas of Earth. For example, the top of Pike’s peak looks kind of like Mars. Alien, yet familiar.
If you haven't seen the NOVA documentary...you should watch it. It's really good. They show the area on earth they used to develop the autonomous landing system...which worked flawlessly, using a helicopter that flew so high, they had to wear oxygen masks.
They also talk about Mars Yard, where they have a duplicate of the rover, as well as all the other rovers that are on Mars, which they use to troubleshoot problems and develop software patches. It's just like in the movie, the Martian.