Scientists have just announced that they have discovered what could be a habitable planet in a close neighbourhood. That’s a planet that is neither too hot or too cold to keep a supply of liquid water at surface level, and so may be able to sustain human life.
Scientists also think it’s between 2 and 6 times bigger than our planet Earth. And it’s “only 12 light years away.” It can even been seen from earth by the naked eye.
Before booking a place on the next space shuttle and packing our bags to emigrate, though, there are several rather steep hurdles to overcome. First of all, along with liquid water, any planet that would be permanently habitable for a species like Homo sapiens would need a sufficient supply of oxygen, have a surface which will produce food, and provide some protection for the lethal rays of the sun.
And we would have to figure out some way to get there. “Only 12 light years” doesn’t sound too far, but it’s just under 70 trillion miles. Our fastest space shuttle currently travels at about 37,000 miles per year. At our current speed of travel, arrival time would be close to 2 billion years after departure.
You see the problem.
Even getting to our closest neighbour, Mars, and setting up house there still is beset by formidable problems. The first is that right now astronauts cannot spend more than six months space without their bones getting soft. Our bones have evolved to live with the impact created by gravity, and even then, we risk severe osteoporosis without sufficient exercise. We don’t know yet how to maintain bone strength for astronauts who may need to be in space for as long as two years for a Mars trip.
One option is to genetically engineer humans with bones which can withstand the weightlessness of gravity for a period of years.
The problem is that, once on Mars, the astronauts will again be subject to the impact of gravity. What will happen to their bones then?
Then, of course, there are the problems of oxygen, food, and water which any one will need to survive the trip to Mars and even a short visit there.
These problems may be solvable. But it will not happen quickly.
I think we’d better keep thinking about keeping Earth habitable for us humans for the foreseeable future.