Humans are by nature curious. Mars is the next obvious step in our exploration of our universe. I hope that we will have habitats on Mars by 2020, with people living there continuously.
This was the only mission I was really involved with - as a SURF summer student at Caltech/JPL. I was examining the blurred parts of Sojourner images that were thought to be due to dust on the lens - something that would help us study dust size, and wind on Mars. However, these marks were actually gasses condensing on the CCD, within the optics, something that we had sent to Mars ourselves! I also worked a few weeks 'counting rocks' and assigning them shapes. This was on a 'floodplain' panorama, and we got to name rocks!