“They say once you grow crops somewhere, you have officially ‘colonized’ it. So technically, I colonized Mars. In your face, Neil Armstrong!” -Andy Weir
In 1960, just three years after Sputnik 1, humans began launching missions to Mars.
After six USSR and USA failures, Mariner 4 successfully flew by Mars in 1965, sending back 21 photos.
NASA’s Mariner 6 and 7 also reached Mars, along with the USSR’s Mars 2 and 3, showing a heavily cratered, Moon-like surface.
Mariner 9 arrived at Mars in 1971, however, orbiting it for over a year and changing our view of it forever.
Mars contained dust storms, extinct volcanoes, and the largest chasm ever discovered on a planet: Valles Marineris.
NASA’s Viking landers, in 1976, returned the first color photos from the surface.
In addition, they tested for signs of life, discovering some evidence for organic materials, but nothing definitive.
Subsequent orbiters allowed us to map out the entire surface in high resolution; we now have a global map.
Meanwhile, landers, orbiters and rovers continued, becoming more advanced and discovering evidence for liquid water.
Most excitingly, methane vents and flowing surface features point towards past — and possibly present — microbial life.
Two upcoming landers, ESA’s ExoMars Rover and NASA’s Mars 2020, will seek advanced biosignatures and unambiguous life signs.
After 50+ years, we’re ready to know.