Photo of Curiosity during descent phase, taken from orbit. This shot is amazing all by itself.
Curiosity in descent phase. Photo taken by NASA’s Mars Reconnaissance Orbiter. Credit: NASA/JPL-Caltech/Univ. of Arizona.
Curiosity is powered by a Pu-238 oxide thermoelectric generator. The Multi-Mission Radiosiotope Thermoelectric Generator, MMRTG, has an output of 2000 watts thermal and 100-120 watts electric. The MMRTG unit sits in the aft end of the rover enclosed by a finned heat exchanger.
Lamentations on Chemistry 
It’s an amazing accomplishment. As the “Bad Astronomer” put it, NASA basically landed a one-ton nuclear-powered robotic mobile chemistry lab on the surface of Mars. Cool stuff.