A ROBOTIC rover has detected living organisms in the driest and most barren place on Earth, the Atacama desert in Chile. A similar rover could one day look for life on Mars.
A team led by Nathalie Cabrol of NASA鈥檚 Ames Research Center in California, along with roboticists from Carnegie Mellon University in Pittsburgh, Pennsylvania, used a 1-metre-tall, four-wheeled rover called Zoe to explore a site in the heart of the Atacama desert. To simulate operating a rover on Mars, the vehicle was controlled remotely from Pittsburgh. The controllers were not told exactly where Zoe had 鈥渓anded鈥�, only that it was somewhere within a large 鈥渓anding ellipse鈥�.
The team could instruct the rover to move to a specified spot, but the rover had to plan its own route and avoid obstacles. The NASA rovers currently exploring Mars have travelled no further than 317 metres under autonomous control, but Zoe went as far as 5 kilometres on its own. 鈥淶oe is the next generation of rovers,鈥� says Cabrol.
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When the team found a site worth investigating, based on images relayed from the rover鈥檚 cameras, Zoe sprayed four fluorescent dyes on the ground, each designed to glow a particular colour in the presence of proteins, carbohydrates, membrane lipids or nucleic acids. The ground was then illuminated by a flash of light, causing the dyes to fluoresce if the biological molecules were present. Zoe could also detect fluorescence from chlorophyll-based life such as cyanobacteria.
In this extremely arid region, the rover picked up signs of what appeared to be cyanobacteria in cracks on some rocks. 鈥淲e weren鈥檛 expecting to see anything there,鈥� says Lauren Ernst, a biochemist at Carnegie Mellon. The team then retraced the robot鈥檚 route and took samples back to the lab, where they confirmed the robot鈥檚 results. There were no false detections.
When they started the project, Cabrol says, the researchers were not sure if 鈥渞emote, unambiguous detection of life was realistic and achievable鈥�. The results 鈥渁re looking very good. It is really exciting,鈥� she told 快猫短视频.
