In the Summer of 1993, it appeared a new era of space exploration was going to a major boost. After Pionneer Venus was launched in 1978, no U.S. planetary probes were launched until 1989. Magellan was sent off to Venus, and Galileo to Jupiter. It was now time for Mars Observer to enter Mars orbit, and begin advance studies of the planet. Unfortunately, this would have to wait until the 1997 arrival of Mars Pathfinder and Mars Global Surveyor. Mars Observer lost contact with earth (it seems now that a fuel line exploded) just before entering Mars orbit, never to be heard from again. Below are the only two resolved images it ever took of Mars. I colorized the image based roughly on somoe wide angle data, with a little editing to make it look a bit more realistic.
Mars Climate Orbiter also failed just before entering orbit too - in this case, due to a metric/English conversion error! This is its lone image - unfortunately, not nearly as detailed as the Mars Observer image.