In a recent presentation sponsored by the Harvard Origins of Life Initiative (origins.harvard.edu), astronomer Lisa Kaltenegger said that it is “within our grasp” to discover small, rocky, Earth-like planets with the potential to harbor life. Kaltenegger works with the Harvard-Smithsonian Center for Astrophysics, a group that has made great strides recently in the search for life beyond our solar system, aided significantly by a new NASA telescope known as Kepler. The Kepler telescope was launched in March 2009, and relies on an advanced photometer, a device that measures the brightness of stars light years away. The Kepler keeps track of the relative brightness of over 145,000 main sequence stars, and by comparing fluctuations, researchers can calculate when a planet is crossing the face of the star, and even what the atmosphere of the planet is composed of.
On February 2, 2011, NASA’s Kepler team announced that the telescope was able to identify 54 planets in the habitable zone of their respective stars, and that data suggests roughly 6% of stars harbor Earth-size candidates, significantly higher than earlier estimates. The habitable zone, also known as the “Goldilocks Zone,” is the distance from a star where a planet can maintain liquid water on its surface, with temperatures that could theoretically sustain life. Researchers have also identified compounds like oxygen, carbon monoxide, and methane as indicators of microbial life, and as research techniques improve, so does the ability of scientists to analyze atmospheric conditions of distant planets from here on Earth.
Researchers like Kaltenegger are optimistic that we may know the answer to whether or not we are alone in the universe within the next five years. So what is next in our search for life beyond Earth? NASA has scheduled the launch of its James Webb Space Telescope for 2014 to replace the administration’s successful Hubble Space Telescope. Relying on advanced infrared imaging, researchers hope the JWST will be able to provide much more detailed views of the Earth-like planetary candidates identified by the Kepler telescope. Lisa Kaltenegger explained that plate tectonics and volcanic activity are important geological processes for the sustenance of life, and are additional factors that scientists are increasingly able to study from afar.
Written by: Walter Palmer