That Opportunity, the robotic Mars Rover has finally succumbed to a massive dust storm is a little sad. No longer responding after nearly a thousand prompts from NASA engineers on Earth, the harsh environment of Mars has proven too much for the veteran explorer at the last. Operating on Mars since January 2004, the mission was originally intended to span 90 days, yet the machine crawled more than the distance of a marathon (42.1 kilometers) between its landing day and when the rover was last heard from on Mars, on June 10, 2018.

One of Opportunity's greatest scientific discoveries was confirming the presence of standing water on Mars over long periods. The rover uncovered the presence of minerals and other rocks on Mars that tend to form in water on Earth, and also found evidence of ancient hydro-thermal systems. Opportunity demonstrated it was possible to operate a rover for more than a decade on another planet, overcoming engineering and driving issues as it continued to perform scientific work. Its longevity was truly remarkable.

The achievements of Opportunity and her sister Spirit seem to point to a way forward for human exploration of the solar system, a necessarily robotic one. Despite the excited talk of a colony for humans on Mars or the Moon, neither of these places are really suitable for life as it has evolved on Earth - in fact - they are positively hostile to it. Mars has a thin, lethal atmosphere, a significantly lower gravity, poisonous soil, very limited protection from radiation, massive dust storms and so on. Anyone planning to be on a mission there in the next twenty years is more than likely to die within weeks or months of arriving. Rescue ships are a long way off and can only leave the Earth during a narrow two year window. Robots are not flesh and blood and will have an increased capacity as they are improved to perform whatever task is required. Yet I know very well that humans will decide to go themselves. It seems inevitable. Finding out the hard way might be the only way forward.

Meanwhile, Oppy sleeps in the Martian sands.