Searching for worlds around other suns isn’t easy. Stars are big and bright, planets are small and unimpressive. Our own sun is 333 times larger than the earth. This means that for a species on another star they would need to have a telescope 333 times better in order to see the earth clearly, even discounting the difference in luminosity. Yet in the last years we have began to discover planets around other stars and the method used to find these objects is the wobble method.
The most commonly known example of the wobble method was not used to discover a planet around another start though but to discover Pluto in our own. As scientists looked at the orbit of Uranus was different than it should be unless there was another object past it. By using this they were able to discover Pluto.
This is not exactly the wobble method but the principles are the same. By looking for the affects that gravity has on stars and finding those that can be explained only by the existence of a planet we are able to prove that there are planets there and with enough work we can even determine the location and size of the planet.
This method for discovering extra solar planets is not without its flaws though. The first of these major flaws is that it is difficult to discover small planets, like the one that we live on, and so in the beginning of this experiment nearly ever planet discovered were not only very large but close to their sun. This is the easiest of the flaws to overcome though and by improving the technology we will be able to see smaller worlds at greater distances.
The second flaw is more difficult. Because the wobble effect is based on the orbit of the planet around the sun worlds that orbit the star at the same speed that the star turns would be invisible to this effect. In our solar system this means that with this method Jupiter would be largely invisible and leaving Jupiter out of the map of the solar system would be like leaving New York City out of a map of New York State.
The wobble method of discovering planets is a new science but one that has dramatically increased our understanding of solar systems. Using it we are able to begin to understand the universe in a way we never could before, recognizing the true diversity of planets and solar systems in ways that we could only imagine before and perhaps most importantly it has proven that planets in our galaxy are not rare. They appear to be nearly everywhere and that means that we might not be alone.
