Kepler space telescope shows its planet hunting stuff

William Atkins
Friday, 07 August 2009 21:18

Science - Space

The exoplanet HAT-P-7b orbits its parent star (HAT-P-7) in just 2.2 days. HAT-P-7 is a yellow white dwarf star located in the constellation Cygnus.

The exoplanet HAT-P-7b is about 26 times closer than Earth is to the Sun, which makes it unlikely that any life exists there. As NASA states, “… the planet is as hot as the glowing red heating element on a kitchen stove.”

The exoplanet is also much larger than Earth, somewhat larger than the planet Jupiter. Combine these two facts together and HAT-P-7b is called a “hot Jupiter” planet.

NASA also states, “Kepler's measurements are so precise, however, they show something new: a smooth rise and fall of the light between transits caused by the changing phases of the planet, similar to the phases of our own Moon. The smooth rise and fall of light is also punctuated by a small drop in light, called an occultation. An occultation happens when a planet passes behind its star.”

The authors make a point of this fact in their paper. They state, “The data for HAT-P-7b show a smooth rise and fall of light from the planet as it orbits its star, punctuated by a drop of 130 ± 11 parts per million in flux when the planet passes behind its star. We interpret this as the phase variation of the dayside thermal emission plus reflected light from the planet as it orbits its star and is occulted. The depth of the occultation is similar in photometric precision to the detection of a transiting Earth-size planet for which the mission was designed.” [Science]

David Koch, the deputy principal investigator of NASA’s Ames Research Center, concludes with the following remark, “This early result shows the Kepler detection system is performing right on the mark. It bodes well for Kepler's prospects to be able to detect Earth-size planets."

As of August 2009^[update], 358 exoplanets have been discovered by astronomers from around the world. Hundreds, if not thousands more, will be discovered over the next several years by Kepler and other such telescopes, both on the ground and in space.

Several of these known exoplanets orbit in their star's habitable zone, so it is possible that Earth-like conditions exist on these explanets. If these exoplanets contain moons, these bodies could also possess life.

The ability to detect primitive life on such exoplanets, however, will be an exceptionally challenging task for astronomers, one that may not be able to be accomplished for many, many more years. However, if any of these planets contain intelligent life, the ability to detect such life may be less difficult.

The ability of science to detect such life forms will progress as we develop better technologies in the future. Only the future knows for sure what we will find in our investigations of our Milky Way Galaxy and beyond.