For a very long time, humans have wondered whether or not we are alone in the vast expanse of space. Thanks to the Kepler Photometer, it now is possible to detect extrasolar planets thousands of light years away from Earth. NASA’s Kepler Mission launched in March 2009 seeks to discover Earth-like exoplanets, and ultimately, habitable planets capable of supporting intelligent life.
The Kepler Photometer in itself is comprised simply of a Schmidt camera. Once commonly used in rear-projection television sets, it has been modified to transmit weekly images of over 100 000 stars located between the “Summer Triangle” (composed of the constellations Vega, Deneb, and Altair) in the Cygnus-Lyra region of space. The Photometer utilizes the transit method of locating extrasolar planets, relying on the detection of a small shift or wobble in a star’s brightness as its orbiting planets pass in front of it.
In modern times, astrophysicists have employed methods such as Doppler spectroscopy; calculating the Doppler shift of a planet in relation to our solar system as it orbits its star. This method has been relatively effective in detecting a multitude of star systems in our galaxy; the vast majority of these planets are not habitable by human standards. It is an unfortunate contradiction as the planets in the “Goldilocks” zone most capable of supporting intelligent life are also the hardest to detect. This is due to the fact that the luminosity and gravitational behavior exhibited by these exoplanets are dwarfed in comparison to their local stars.
Similarly, the transit method also favors planets that are dangerously close to their respective stars, or else “star-like” planets such as our gas giant Jupiter. However, due to the improved precision of NASA’s Kepler Photometer, it is now possible to detect a variation of as little as 1% in a star’s brightness; thus, there is an increased chance of detecting habitable exoplanets. Once detected, the planet’s orbital size can be calculated from the period of revolution around its star as well as the mass of its star, using Kepler’s Third Law of planetary motion, hence the nickname adopted for this Discovery mission. NASA is able to ascertain further characteristics of these exoplanets – even its characteristic temperature, for example, by calculating its orbital size and star temperature.
Following NASA’s first report in January of 2010 on the Kepler mission’s preliminary findings, it has been revealed that 8 new exoplanets have already been discovered as a result of this new operation, the smallest of which is less than 4 times the size of our earth. With just under 3 years left in its current mission mandate, the most promising results of the Kepler mission are yet to come. Experts have pinned the orbital period of a habitable exoplanet to roughly 1 standard Earth year, depending on the size of the star. As the first year of the Kepler mission approaches, NASA stands poised to collect further data on the existence of habitable exoplanets. In the years to come, NASA’s latest endeavor in space exploration will be followed with great interest by academics and stargazers alike who ponder the many wonders of our universe. Undoubtedly, the Kepler mission will provide extraordinary new insight into the mysteries of space, humanity’s final frontier.