<p>PASADENA, Calif. (AP) - NASA's Spirit rover discovered more evidence of past water activity on Mars, although not in as great amounts as the twin rover Opportunity found on the other side of the planet, mission scientists said Thursday.</p>
<p>The findings come from analysis of a rock dubbed Mazatzal in the Gusev Crater region where Spirit landed on Jan. 3. Since then Spirit has been overshadowed by Opportunity as it found signs that extensive water, possibly a salty sea, once covered its landing site on Meridiani Planum.</p>