As many as half of Scotland's drivers are keen to cut back on their use of cars to reduce stress and to protect the planet, according to expert research for the Scottish Executive.
They are defined as either "malcontented motorists" who find driving a strain or "aspiring environmentalists" who want to limit their pollution. Researchers estimate that together they make up 48% of drivers.
The radiation encountered on a journey to Mars and back could well kill space travellers, experts have warned. Astronauts would be bombarded by so much cosmic radiation that one in 10 of them could die from cancer.