Following the water

The following is an excerpt from an editorial in the Guardian of London:

When ancient explorers set off from home they would follow the water, along rivers and coastlines, from lake to lake. There was little else they could do, for water is unique. The simple combination of hydrogen and oxygen is crucial for life as we know it. Without liquid water, cells fail, and so do those functions that define us.

The U.S. space agency put the same intuition at the heart of its exploration of Mars. On our home planet, where there is water, life is never far away. And it is this that makes NASA’s latest discovery so exciting: that water may flow on Mars today.

To find living organisms on Mars would rank among the most important discoveries in history, as no longer could life on Earth be considered unique.

But is it all worth it? The Mars Reconnaissance Orbiter, whose instruments detected flowing water on Mars, cost NASA nearly $750 million a decade ago. There are some who would argue that, instead of blasting robots into space, we should build more hospitals here on Earth. But that is shortsighted. The money was not launched into a void. It was spent here on Earth, on problem-solving. Space is the toughest environment we have to work in, and creates fiendish problems that need smart people to solve them. Smart people who cut their teeth in the space industry move into schools, engineering firms, life science companies.

The problem facing NASA now is what to do next. International agreements forbid space agencies from contaminating other planets with bugs from home, and so the Curiosity rover, with its earthly bacteria, cannot start digging around for alien organisms.

A joint European-Russian rover named ExoMars might take on the task. The robot will be as clean as the 1970s Viking landers, and aims to drill two metres under the surface to look for past or present life. These new explorers deserve celebration, and — as ever — water will be their guide.