NASA’s Mars rover Spirit has reached a safe site for the Martian winter, while its twin, Opportunity, is making fast progress toward a destination of its own. The two rovers recently set out on important — but very different — drives after earlier weeks inspecting sites with layers of Mars history. Opportunity finished examining sedimentary evidence of ancient water at a crater called “Erebus,” and is now rapidly crossing flat ground toward the scientific lure of a much larger crater, “Victoria.”

The Jet Propulsion Laboratory has just completed building twin rovers that will launch to Mars in May and June of this year. This is the first and last opportunity to see both rovers while they are still in JPL’s Spacecraft Assembly Facility before they are packed up and sent to Cape Canaveral, Fla., to be prepared for launch. Reporters will be able to don protective “bunny suits” to get an up close view of the rovers inside the clean room. Reporters who enter the clean room must be wearing long pants and closed toe shoes. No shorts, skirts or sandals are permitted in the clean room.