Wednesday, March 28, 2012

There are billions of Earth-like planets in our Milky Way

The notion that we are unique and alone in the universe is rapidly fading. Astronomers have already successfully identified several Earth-like planets, and even though we haven't found life yet, it is likely that it exists somewhere in the universe. We may even be able to find it in our own galaxy, as scientists now believe there are tens of billions of Earth-like planets in the Milky Way. How long will it take before we find the first forms of alien life?

Red Dwarfs
Observations by the European Southern Observatory have focused on detecting specific types of stars floating around in the Milky Way: Red Dwarfs. With a special technique, it is possible to determine whether there are planets orbiting a specific star. To achieve this, scientists use the Doppler effect, which is basically the sound effect you experience when a car passes you by. When light is emitted from a star, pretty much the same thing happens: bodies that move away from us have different wave frequencies compared to those that move towards us. By measuring the frequencies of Red Dwarfs and incorporating a lot of complicated mathematics, scientists at the ESO were able to determine that our galaxy is quite rich in planets orbiting a star, much like the Earth orbits the Sun.

After measuring about 102 Red Dwarfs, a tiny fraction of the billions of stars in our galaxy, the scientists deduced that there must be billions of planets orbiting all the stars in the Milky Way. As much as 40 percent of the Red Dwarfs are thought to possess a planet within the so-called habitable zone. That means they orbit their star at such distances that temperatures allow for liquid water, a prerequisite for life as we know it. Because there are billions and billions of stars, the number of possible Earth-like planets is unimaginably big.

A closer look
One would expect to find life on at least a few of the Earth-like planets orbiting a Red Dwarf. The astronomers are therefore taking a closer look at a couple of the star systems with planets in the habitable zone, hoping to find something interesting. It adds to previous and recent findings from, among others, NASA; the space organization used the Kepler space telescope to uncover an interesting planet with Earth-like characteristics. 

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