Astronomers used the NASA Spitzer Space Telescope to see planets outside our solar system for the first time ever. Previously, scientists have inferred the existence of more than 100 planets by detecting a gravity-induced wobble or shift in light in the stars that they orbit. Yesterday, the astronomers at the Harvard-Smithsonian Center for Astrophysics and the Goddard Space Flight Center announced that they directly observed the infrared radiation emitted by two planets 153 and 500 light-years away. (Seen here is a NASA artist's concept.) From the New York Times:
They said directly measuring light from the planets was a major step in the quest to understand what alien planets are made of, because different molecules in the atmosphere absorb infrared light in characteristic ways and allow scientists to compare these alien planets to those in the solar system. Ultimately, astronomers would like to know if Earth, with its ability to evolve and support life, is unique or common in the universe….Dr. Geoffrey W. Marcy, a planet hunter at the University of California, Berkeley, called the results "the stuff of history books" and added, "With this result, we are closer to understanding our own human roots, chemically, among the stars."
