Life on Mars If the surface life has been reanimated as recently as 450,000 years ago, then rovers on Mars could find dormant but still viable life at a depth of one meter below the surface, according to an estimate. In 1965, the Mariner 4 probe discovered that Mars had no global magnetic field that would protect the planet from potentially life-threatening cosmic radiation and solar radiation; observations made in the late 1990s by the Mars Global Surveyor confirmed this discovery. Scientists speculate that the lack of magnetic shielding helped the solar wind blow away much of Mars's atmosphere over the course of
Space probe comet 67P/Churyumov-Gerasimenko in November 2014. First probe to Jupiter. Radio communications were lost with Pioneer 10 on January 23, 2003, because of the loss of electric power for its radio transmitter, with the probe at a distance of 12 billion kilometers (80 AU) from Earth. First probe to fly by Saturn. (Communications were later lost due to power constraints and vast distance.) "Voyager 1" is a 733-kilogram probe launched September 5, 1977. It visited Jupiter and Saturn and was the first probe to provide detailed images of the moons of these planets. "Voyager 1" is the farthest human-made object from