Whether the rock varnish is rich in manganese, and whether nature or past or present life created it, are questions that could be tackled by two U.S. rovers and one European lander that are scheduled to reach the red planet in 2003 and 2004.

CNN: Researcher: Mars rock varnish hints of life

An hour and a half later the group reaches "the dome, " a 60-foot-high semicylinder of rock, one half of the face a deep blue manganese, the other bridal-white calcite.

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