NASA's Kepler Telescope Detects 150 Earth-Sized Worlds

For at least the last several decades, people have wondered about planets orbiting other stars than our own. How many are there? How many of them are like our own Earth? It looks like NASA's Kepler Telescope has come close to answering those questions.

According to CNN, astronomer Dimitar Sasselov recently announced that the Kepler Telescope, launched last year by NASA, has so far detected 150 Earth-sized planets. Sasselov went further and suggested that there may be as many as 100 million Earth-like planets, with conditions similar to our own, in this galaxy alone.

The Kepler detects planets by measuring how much and how often a star's light dims, indicating a planet. In this way, the size and the orbit of a planet can be determined.

The implications of this announcement are staggering in their scope and implications. 100 million Earth-like planets means 100 million chances that life could evolve in other places in our galaxy. Some of that life would, by the law of averages alone, evolve into intelligent life.

In the long term, meaning centuries, there may be up to a 100 million more places where human beings can live.

The next step would be to build telescopes that would be powerful enough to image those planets to measure the composition of their atmosphere and whether they have a significant amount of liquid water. The Terrestrial Planet Finder, a space-based telescope proposed but not funded, is one possibility. Others have proposed building a telescope on the surface of the Moon, located on the lunar farside.

Next, robotic probes could be launched to candidate worlds to study them more closely. Even with propulsion systems that could propel such a probe at close to the speed of light, such missions would take place over many decades. Data and images from an extra-solar planet, even orbiting one of the closer stars, such as Alpha Centauri or Tau Ceti, would take years or even decades to reach receiving stations on Earth.

Human explorers to such planets would necessarily be human colonists. Voyages to Earth-like planets circling other stars would take place over many years, though those years would be experienced quicker on board a ship traveling close to the speed of light, due to relativity effects. An entire world to study would be the work of many lifetimes. The first interstellar explorers would also be the seeds of new branches of human civilization.

Will there come a time when ships, like those depicted in shows like Star Trek, ply interstellar space, visiting brave new worlds in voyages lasting a few weeks? Recent research suggests that physics does not preclude something akin to "warp drive," that if one can create a bubble of space-time around a ship propelled by something called "negative energy," then one can voyage from solar system to solar system like the crew of the Star Ship Enterprise.

Of course, the technology necessary to carry out such a feat would be as unimaginable to people in the early 21^st Century as an atomic-powered aircraft carrier would be to-say-someone living during the Elizabethan Age. Some scientists maintain such technology is impossible.

But the late Arthur C. Clarke once said that when an elderly but respected scientist says something is possible, he is usually right. But when the same scientist says something is impossible, he is almost invariably wrong.

Sources:

Kepler Planet-Hunting Space Telescope Launches, Mark R. Whittington, Associated Content, March 7th, 2009

Our galaxy is rich in Earth-sized planets, CNN, July 27th, 2010

The Terrestrial Planet Finder, Homepage

Lunar Observatories: Grand Plans vs. Clear Problems, Jeanna Byner, Space.Com, December 5th, 2006

Five Real Life Possibilities for Interstellar Travel to Other Stars, D. Vogt, Associated Content, January 10th, 2010

Star Trek's Warp Drive: Not Impossible, Clara Moskowitz, Space.Com, May 6th, 2009