Dan Werthimer, director of the Search for Extraterrestrial Intelligence (SETI) Research Center at UC Berkeley, spoke to Congress May 21 about the chances of finding alien life. Werthimer addressed the U.S. House of Representatives' Committee on Science, Space and Technology in hopes of keeping funding.
Seth Shostak, an astrobiologist at the SETI Institute of Mountain View, Calif., also spoke to lawmakers on the issue.
Experts on the space program told Congress about the current search for life on other planets. Contributions of the Kepler spacecraft, launched in 2009 to find new planets, were highlighted in the remarks. That mission discovered thousands of potential alien worlds, and hundreds have been verified.
Kepler revealed our Milky Way Galaxy contains an estimated one trillion planets. That is an average of three or more planets per star.
"Billions of these planets are Earth-sized and in the 'habitable' or so called 'Goldilocks' zone -- not too distant from their host star (too cold), and not too close to their star (too hot). And there are billions of other galaxies outside our Milky Way Galaxy -- plenty of places where life could emerge and evolve," Werthimer told Congress.
The Drake equation is a method of estimating the number of technologically advanced civilizations in the galaxy. The equation takes the estimated number of stars, and multiplies that by fractions that have planets, develop life, harbor intelligent life, etc. When it was first conceived by American astronomer Frank Drake in 1961, many of these quantities were highly uncertain. Given the tremendous number of probable planets in the galaxy, the chance of life, as calculated by the procedure, rises dramatically.
Radio and television signals from Earth have been leaking into space since the middle of the 20th century. Traveling at the speed of light, the first broadcasts from Earth are 65 light years away from our world. The first episodes of "Star Trek," broadcast in 1966, are just now reaching Alpha Cephei, 48 light years away.
Many SETI programs are listening for similar signals leaking into space from distant worlds. Werthimer believes aliens are likely to use more direct methods of communication, such as tightly focused beams. "Eavesdropping SETI" is a program aimed at detecting these signals when planets are properly aligned.
The Panchromatic SETI Project will soon begin a coordinated effort studying planets orbiting 30 stars within 13 light years of Earth. The mission will utilize telescopes at six observatories, including Keck in Hawaii and Arecibo in Puerto Rico, the world's largest radio telescope. This project will closely examine the nearby planets over a wide range of wavelengths. This could help astronomers hear messages from the stars, just as if hearing were suddenly expanded to include higher and lower notes than normal.
Two of the radio observatories in the study are in danger of closing due to funding issues.
