The news was released around September 29th: Astronomers had found the most Earthlike planet yet. The new exoplanet, meaning a planet outside our solar system, is called Gilese 581g, and may harbor life. Gilese 581g is 3 times the mass of earth, and orbits it's star, Gilese 581, in 37 days. This may seem like a close orbit and a large planet, but jet fighter pilots survive at 3 Gs. (One G is the gravity of earth; 2 Gs is twice the gravity of Earth, not to be confused with grams, which is about the weight of a paper clip.) The orbit of 37 days may seem like a short orbit, implying a close orbit and high temperatures, but Gilese 581 is a red dwarf, and therefore smaller and less bright than our sun. Another oddity is the length of Gilese 581g's day, it lasts forever. Due to what astronomers call "tidal forces" (because they are the same forces that cause the tides), one side of Gilese 581g always faces it's sun. The other side is in permanent darkness. Any life would exist on the band between the two sides. The area between "too close to he star!" and "too far away from the star!" is called the goldilocks zone: not too hot and not too cold. Gilese 581g's orbit is right in the goldilocks zone.
However, one of the most amazing things about Gilese 581g is not its relatively small size or distance to its sun, but its distance to earth. Gilese 581g is only 20 light-years from earth. (Contrary to many people's beliefs, the light-year is actually a unit of measurement, which masures the disance light travels in a year in a vacum.) Although most would consider this a very long way, 20 light-years is an astoundingly short distance in porportion to the size of our galaxy. If humans could develop a space ship that could go half the speed of light, a probe could return results within sixty years, a short time in comparison to the scale of the universe. Not only that, but according to Einstein’s theory if relativity, as speed increases, the time experienced by the object moving decreases! This means that a hypothetical astronaut would be able to make it there within the confines of her/his lifetime!
Although most reading this right now will probably not live to see the results of a mission, it’s something the human race should probably consider, for the sake of our children and to perhaps answer the ultimate question: “Are we alone?”
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