It has been exactly two decades since NASA's Pathfinder mission touched down on the surface of Mars.
There was a time when the idea of operating a remote-controlled vehicle on another world was the stuff of science fiction, but on July 4, 1997, the dream became a reality when the Pathfinder mission, which brought with it a small rover known as Sojourner, touched down on the Martian surface.
It was the first successful Mars landing for NASA since the Viking missions in the 1970s and the rover, which was designed to operate for one week, managed to keep going for three whole months.
The mission was followed up in 2004 by the landing of two twin rovers, Spirit and Opportunity, which began scouring the planet's surface for evidence of its watery past.
Spirit sadly stopped working back in 2010, two years before NASA's car-sized Curiosity rover landed in Gale Crater, but incredibly, Opportunity remains operational even to this day.
"Pathfinder initiated two decades of continuous Mars exploration, bringing us to the threshold of sample return and the possibility of humans on the first planet beyond Earth," said Michael Meyer, lead scientist for NASA's Mars Exploration Program at the agency's headquarters in Washington.