It is a well-known fact that the movie "The Martian" was considered to be one of the most accurate movies scientifically. In fact NASA themselves have been impressed with the accuracy of details expressed in the movie. NASA has even gone to the extent of using the movie as a marketing campaign for the 2030s actual manned mission to Mars. That's how impressed they are.
The movie is based on the book written by Andy Weir and is considered close to perfect. The director of the movie requested NASA to check the film and make their corrections. Here are a few science based concepts from the movie.
The storm of dust
The storm of dust that starts up the movie is not right. Mars is thought to have dust storms but because the atmospheric pressure is very low the wind produced becomes minuscule. The dust however is considered very harmful.
Time taken to travel
The most accurate of them all is the accuracy of time travel between both the planets. The movie talks about spaceflight where it would require about 8 months to get to mars making use of all the modern technology.
The movie has it that the actor lands on Mars and is able to grow potatoes. The mineral and chemical content of Martian soil may make it possible for plants to grow and therefore this concept is accurate too.
There is a high possibility of developing radiation related disease when one is exposed to high radiation for an extended duration of time. The movie shows the astronauts spending a lot of time on Mars whereas in reality the astronauts stay within the Earth's magnetosphere.
The tornadoes are tear up the surface in the movie and one may wonder how can this be possible if the atmosphere is thin. But it seems true that there is a possibility of tornado formation in the form of whirlwinds that take up the debris on the surface. Though they might not be as dramatic as in the movie, they do exist.
The actor in the movie has no problem moving about and he in fact moves just like he would on Earth, however since the gravity of Mars is only about 30% as of Earth, the movement will be different.
The habitat used in the movie is an inflatable one and this is something that is being considered in reality. Though with the thin atmosphere a habitat with earth like environment might have too much pressure within, this is not an idea to be dismissed easily.