The Next Step Toward a Second “Earth” In an article from MSNBC entitled “Planet Quest Crosses New Threshold,” Scientists Geoffrey Marcy of the University of California at Berkeley, Paul Butler of the Carnegie Institution of Washington and Steve Vogt of the University of California at Santa Cruz, using the Keck Telescope in Hawaii have detected two new planets orbiting distant stars that have given the scientific community a renewed hope that a second “Earth” may well exist. Until recently, the more than 30 planets discovered by stargazers have been very large. A planet roughly the mass of Jupiter is incapable of sustaining life because of the relatively low density and gaseous composition. Smaller planets are denser, and more likely to sustain life such as that on Earth. Unfortunately, smaller planets are more difficult to locate from very far away.These scientists have been able to detect two new planets roughly 70% the mass of Saturn, making them the smallest yet discovered outside our own solar system. These planets are too small for even the most advanced telescope to detect directly. They are, in stead, detected indirectly using the “wobble effect” that they exert on their respective suns. According to Newton’s laws of physics, for every action there is an equal and opposite reaction, and as the planets revolve around their stars, they pull the star a little. This “wobbles” the light emanated from the start headed toward Earth. The scientists detect this distortion in the light, and were able to determine the minimum mass of these two planets. With this new “wobble effect” method of planetary detection, and the discovery of smaller, denser planets, scientists are hopeful of finding a second Earth some where out in the cosmos. ...
