Ken Rice: Breathing life into the Mars debate

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At 6.32am BST yesterday, after what has become known
 as “the seven minutes of terror”, Nasa’s Mars Curiosity rover, part of the Mars Science Laboratory, landed on the surface of the Red Planet.

This latest Mars rover landed in Gale Crater and will spend the next two years crawling slowly (no more than 30 metres an hour) studying Mars’ climate and geology with a prime goal of determining if Mars has been, or could still be, habitable. Although the initial mission is planned to last for two years, there is every expectation that the Mars Curiosity rover will operate for much longer than this, potentially for ten years or more. The rover gets its energy from a 
radioisotope power system that generates energy from the heat of plutonium’s radioactive decay. This means that, since it doesn’t rely on solar power like earlier rovers, it can operate throughout the Martian year.

The Mars Curiosity rover is twice as long and five times heavier than the previous rovers Spirit and Opportunity. It carries ten scientific instruments, with a scientific payload 15 times the mass of that on Spirit or Opportunity. One of the main goals is to determine if Mars ever had an environment able to support small life forms known as microbes. We already know that Mars has frozen water and there is some evidence to suggest that liquid water may have existed on the surface in the recent past. We have also detected methane in Mars’ atmosphere. Although we believe liquid water is necessary for life and methane may indicate life, neither of these is sufficient to really suggest that life exists, or has existed, on Mars.

The Mars Curiosity rover will use a laser to study the composition of rocks and will use a scoop and drill at the end of a robotic arm to gather soil and powdered samples of rock interiors. These will then be analysed by laboratory instruments inside the rover. Although the rover will not have instruments that could determine if live ever has, or still does, exist on Mars, it will be able to determine a great deal about Mars’ past climate and geological history. It will look for chemicals that are thought to be the building blocks for life and will establish how much water (and carbon dioxide) has been present on Mars and whether or not there was ever an abundance of liquid water.

To date, the only life that we are aware in the universe exists on our own planet. Determining if Mars could have been habitable will be a major step towards establishing if life exists elsewhere in the universe. The next steps for Mars will be to consider a sample return mission that would collect rocks and soils and send them back to Earth for analysis, and to consider the 
possibility of human exploration. Successfully landing a massive rover on Mars shows that we have the capability to land something that could potentially return to Earth. The radiation detectors on the Curiosity rover will also allow us to study potential hazards that any future crews might encounter.

Beyond Mars, there are moons of Jupiter and Saturn that may have conditions suitable for life and there are now more than 700 known planets orbiting stars other than the Sun. Very soon we will have a subset of these planets that may also have conditions suitable for life.

So the “God of War” will be revealing some of his secrets. The Red Planet has fascinated mankind ever since they looked into the heavens. At the moment, the planet is on the far side of the solar system, and is gradually disappearing from visibility from Earth. In the latter half of 2013 it will steadily brighten, and by spring 2014, when Curiosity is nearing the end of its planned life, the planet will be dominating our skies in the constellation of Virgo, outshining all the stars.

It should capture the imagination of both young and old when it is realised that on that bright light in the sky is one of mankind’s greatest achievements.

• If you would like to inspect rocks from another solar system body, visit the Royal Observatory this week. It has specimens of Moon rocks gathered during the Apollo missions, as well as meteorites which have fallen from space. To book places on Wednesday or Friday, 2pm-3.30pm, call 0131-668 8404. Adults £4, children (must be eight years or over) and concessions £3.

• Dr Ken Rice and Dr Russell Eberst are 
Edinburgh University astronomers at the Royal Observatory

BUBBLE TROUBLE FOR TEST VOLUNTEERS

Scientists are already making preparations for the possible human colonisation of Mars.

Eight volunteers locked themselves inside a self-sufficient bubble for two years in the early 1990s in an attempt to test out the kind of facility needed to survive on Mars. The air-tight biosphere in which they lived near Tucson, Arizona, was large enough at three acres for the volunteers to grow their own food, take care of

animals and produce oxygen.

The experiment was not without problems. The volunteers had to break into their emergency food supplies before the end of the first year and oxygen

fell so low after 18 months that the biosphere

needed injections of extra air.

They also found that unwanted pests such as cockroaches thrived. An attempt to repeat the experiment shortly after had to be abandoned after being sabotaged by an embittered former team member opening an outside door.