NASA's Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system. The planets, Kepler-20e (pictured) and Kepler-20f, are too close to their star to be in the "habitable zone" where liquid water could exist on a planet's surface, but they are the smallest exoplanets ever confirmed around a star like our sun. Artist's concept: NASA/Ames/JPL-Caltech
Robert Stencel holds the William Herschel Womble Astronomy Professorship at the University of Denver and is director of DU’s Chamberlin and Mt. Evans observatories. His research focuses on stellar evolution and infrared instrumentation. He notes that important astronomical events for Denver and the region in 2012 include an annual eclipse of the Sun on the afternoon of May 20, and on the afternoon of June 5, a rare transit of Venus across the Sun (the last one until next century). DU will host the public at the historic Chamberlin Observatory for these events (weather permitting).
What’s the significance of NASA’s discovery of two Earth-sized planets?
This discovery has at least two significant aspects: (1) finding the first Earth-sized planets helps to confirm the theory that a diversity of planets should exist around many stars, not only the giant, Jupiter-sized planets already discovered; and (2) if we can continue to identify new Earth-sized planets, we may eventually find cases that fall in the not-too-hot and not-too-cold orbital zone where liquid water is able to persist. As liquid water is essential for life as we know it, such planets could harbor unique life forms and potentially provide an ever-expanding Earth human population with havens someday.
Looking back at 2011, what do you think were the year’s biggest advancements or milestones in astronomical research and space exploration, and why?
2011 was another exceptional year, thanks to the hard work and preparation of rocket scientists for years preceding. Some of the achievements included the continuing success of the plucky Mars rover named Opportunity, which just arrived at the large crated named Endeavor. Similarly, the Cassini orbit continues to provide spectacular images and data from its lofty perch in orbit around planet Saturn. Newly in orbit during 2011 at both planet Mercury and at asteroid Vesta are the spacecraft named Messenger and Dawn. Mercury had not been fully mapped prior to Messenger’s arrival, and the sun-scorched scene is illustrating how planets close to their host stars manage to survive for eons, while the asteroid Vesta is one of the largest of that class of objects orbiting between Mars and Jupiter and the first of its size to be visited. The early data already reveals composite terrain unexpected in solar system formation theory. Also, lest we forget, the brave crew of Expedition 30 is aboard the International Space Station, orbiting overhead 15 times a day. Despite supply problems related to the end of the Space Shuttle program (also in 2011), they continue to explore the benefits of the otherworldly microgravity environment.
In an era of soaring budget deficits, how do we justify federal funding for astronomy research?
Astronomy inspires and challenges. Since ancient times, people have learned to use the stars for time and calendar keeping. Movements of the planets inspired theories of gravitation and helped promote physics and engineering, and continue to offer extreme tests for both — relativity/cosmology and spaceflight. Finally, astronomy gives us “the biggest picture” of the universe and our place in it and provides lessons about why we should take better care of this special planet we depend upon. In addition, there are more ways in which astronomers directly can help society: searching for potentially hazardous near earth asteroids, identifying the environmental hazard associated with and finding solutions to light pollution, and frontier exploration with technology and theory that both challenges and inspires participants, students and citizens. The resulting expansion of knowledge and awareness of our cosmic home contributes to the public good.