Over the past decade scientists have discovered hundreds of new planets, some of which are habitable like earth. There are two methods that scientists use to discover these planets. The first method is called the Photometric Transit or “wink” method. This method relies mainly on a planets orbit across the disc of its parent star in our line of sight. The other method, which is what most scientist use, is referred to as the wobble method. Through this method, we predict the presence of planets by the effect they have on the star they orbit.
Planets outside of our solar system are called exo planets. Most exo planets are found using the wobble method. In this method scientist are looking for stars that appear to wobble because of the gravitational pull of their orbiting planets. This is an indirect method where the planets existence is inferred due to the offset or unbalance of the star they are revolving around. By using the Doppler effect, we can tell if a star has a planet revolving around it by looking at its spectrum. If the spectrum fluctuates continuously from high to low frequencies, after you have accounted for the earth moving in respect to the star, then that means the star is the one that is moving. If this is the case, then one might correctly conclude that a planet is orbiting the star and the planets gravitational pull is what is making the planet move.
Unlike the wobble method, scientists using the transit method are able to obtain more information about the planet such as its orbital path, size, and chemistry. In the transit method, scientists observe a planet passing in between the earth and its star. The planet partially blocks the light that its star is emitting. The amount of light blocked is very small and it would have to be periodic for it to be caused by a planet. Also this change would have to last for the same amount of time, and have the same change in brightness, if it were the same planet crossing in front of the star. This provides an accurate detection method for finding new planets.
Scientist from the University of California, Berkeley, and the University of Hawaii, Manoa, have determined that twenty percent of sun-like...