First things first: I never read the book. There is no specific reason, I just didn't. From what I gather the story very much deviates from the book so much that even Bradbury itself didn't liked it. In any event, this show can't be judged by it's looks, it's OK but even for 1980 it looks cheap. And, of course, you can't take the science seriously now but you should be aware that this was written from 1946 onward and published in 1950 and at that time, well, they just didn't know better. To change it in the show would not have been right, anyhow it was cheaper to produce that way.
About the show itself: the first part is actually not bad. The second was [spoiler] too religous for my liking and the third had that stupid part with the blonde. But it also has the meeting between Wilder and the Martian which was really well written with good dialogue. [/spoiler] Alltogether the massage is a good one, it is a very critical story about colonisation and the destruction of other cultures. Many things are true even today and I am always amazed how visionary writers like Bradbury have been. So, it's probably better to read the book than watch this series. But if you do, don't judge the book by it's TV adaptation I'd say.