Evocative Debris, Orbital Opportunity Astrobiology Magazine

As you saw with Spirit, said Tim McElrath of the Opportunity’s navigation team, “we have a number ways to locate a rover. The 44 by 5 miles across, that error ellipse was what we worked for six months to define before landing. We were fortunate to have two Deep Space Network tracking stations, so we could see two-way Doppler data all the way down during descent until the parachute opened. ”