International Computer Magazine
The Second Earth
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12 of which have diameters between one and two times Earths, and orbit in their star's habitable zone. Nine orbit stars similar to ours in size and temperature. Exoplanets, especially small Earth-size worlds, belonged within the realm of science fiction just 21 years ago. Also Germany’s European Southern Observatory announced the discovery of a new habitable planet. The new world is just slightly bigger than Earth and sits about four light years away, orbiting Proxima Centauri. That star is the nearest one to our solar system. The planet, known as Proxima b, is close enough that future generations of space craft might be able to travel there, taking robotic probes with them. Eventually it could even be close enough to become a new home for travellers from Earth Proxima b is far closer to its star, taking just 11.2 days to complete one orbit and sitting only 5% as far away from its star as we do from ours. But because that star is much dimmer, it is still within the habitable zone where there could be water on the planet – and, as a consequence, life. But there are other issues with Proxima b, the star pelts its planet with powerful ultraviolet rays and X-rays, which would mean that anything living there would find it much harder and so would have to become hardened against |
that radiation. The planet is thought to be in the star's 'habitable zone' - an area around a star in which an orbiting planet's surface could hold liquid water. For humans to survive we need oxygen, therefore any planet which does not have oxygen would be unsuitable for us to live on. We also need a supply of water. We need water for many reasons such as to grow food or for other animals. We need a certain amount of sunlight and we need a planet which is neither too hot nor too cold. A planet with stable temperatures between 0C and 40C would be suitable. We also need an atmosphere to shield off the harmful rays from the sun. Below the different planets in our solar system are considered whether they fulfill the basic requirements for life. |