The Search Tool is how you quickly find a particular person, vehicle, or settlement. It can get very handy when you want to check up on something you've left for something else.
Try selecting a person, vehicle or rover from the list and double-clicking on it. This opens the unit's info window and centers your map on the unit (if you have the Mars Navigator tool window open). You can close the unit window or leave it open - it automatically updates when something related to the unit changes.
Click this link to go forward to Step 6, or this link to go back to Step 4.