Searching for habitable planets in Science Fiction
Posted on December 3, 2011 by Tom
I saw a recent article where astronomers had located a planet that they felt may plausibly support life. It was twenty light years away from earth (1) .
“This is really the first ‘Goldilocks’ planet, the first planet that is roughly the right size and just at the right distance to have liquid water on the surface,” astronomer Paul Butler, with the Carnegie Institution in Washington, D.C., told reporters during a conference call Wednesday.The speed of light is 186,282 miles per second and when we multiply this times twenty years, this planet can be seen to be seventeen trillion miles away. What if we don’t happen to have a ship that can travel faster than light? Apollo Ten hit a staggering 24,791 miles per hour during its return from the moon. At this speed, the trip takes nearly five billion years. So, what if we use the speed of the Helios 2 space probe which went 149,968 miles per hour? The trip can be shortened to 783.5 million years.
“Everything we know about life is that it absolutely requires liquid water,” he added. “The planet has to be the right distance from the star so it’s not too hot, not too cold… and then it has to have surface gravity so that it can hold on to a substantial atmosphere and allow the water to pool.”
With a mass three times larger than Earth’s, the newly discovered world has the muscle to hold atmosphere. Plus, it has the gift of time. Not only is its parent star especially long-lived, the planet is tidally locked to its sun — similar to how the moon keeps the same side pointed at Earth — so that half the world is in perpetual light and the other half in permanent darkness. As a result, temperatures are extremely stable and diverse.
The next consideration is a planet’s gravity, which is determined by the planet’s mass. (2) This further narrows the field of host planets for our science fiction adventures down. Note that the planet in our example has a mass three times that of Earth. I believe that the gravity there would be too much for humans, so we need to extend our search.
The extreme numbers and distances involved in space exploration lead science fiction writers to use tools like faster than light space ships and worm holes to plausibly get their characters to planets in some other universe’s Goldilocks zone.