THERE鈥橲 no need to cry over spilt chemicals. Thanks to an accident inside one of its instruments, NASA鈥檚 Curiosity rover has detected the presence of a substance called perchlorate in Martian soil (see 鈥�Curiosity鈥檚 spills add thrills to the Mars life hunt鈥�).
Not exactly earth-shattering, you might think. But it adds a new twist to the most controversial chapter in Martian history: did the Viking landers detect life?
This is a question that has divided the Viking missions鈥� researchers for almost three decades. One group has resolutely stuck to its guns that the landers detected signs of life. Equally adamant is a second group who say they absolutely did not 鈥� a view that has always been the official version of events.
Advertisement
The unexpected discovery of perchlorate supplies a legitimate reason to reopen the debate. Perchlorate is an oxidising agent that destroys organic molecules. Its presence could finally explain the disputed results.
The episode highlights another important issue. Curiosity is a sophisticated machine, but there is only so much soil chemistry we can do from millions of kilometres away. A sample return mission must be a priority.
This article appeared in print under the headline 鈥淲e need a piece of Mars鈥�
