How come the mars missions like spirit and oportunitis dont carry out a real video camera insted it snaps pic?

Question

i mean like the moon missions. not unless they do and i can't tell

Answer 1

It takes energy to power those cameras and those power is need to power other equipments. A live video feeds is very hard since radio waves from have to travel through the martian sky and it takes a pretty long time for radio waves to travel from mars to earth.  

Answer 2

There are a couple of reasons.

For one, the moon missions consisted of human visitors and lots of gear... so they brought both still and video cameras. The video was quite nice for posterity, for human viewers, etc... but not terribly useful for scientists, due to its low resolution.

On Mars, it's a different case... you have a robot, not a human. There's nothing terribly interesting to view in realtime. The data channel back to Earth is tiny, so it takes awhile to send back photos with minimal compression... but photos are far more useful for scientific purposes; they're higher detail, and the only thing moving is the robot itself. And every piece of gear on the robot is VERY expensive to get to Mars, it has to fit into the power budget, etc... so it has to be very useful.