Large Binocular Telescope
By John Cowens, guest blogger
Raised in Bluffton, Ind., John Cowens received a bachelor’s and master’s degree from Indiana University. He is a master elementary and middle school teacher with 32 years of experience. During his teaching career, Cowens was awarded several prestigious teaching awards, and from 1999 – 2007, he was also a science columnist for Teaching K-8 magazine and received an award for “contributing outstanding science lessons.” Since 2002, he has served as NASA’s Jet Propulsion Laboratory’s Solar System Ambassador and disseminates space exploration information (i.e. images from the Hubble Space Telescope) to the general public via school assemblies, general public meetings, which often include star parties with his 14” reflector telescope.
Cowens will be presenting during Evergreen’s Member Appreciation Month in February, and will also be a regular speaker at the Museum Star Parties this summer.
The Hubble Space Telescope (HST) received its last repair in May 2009, and if all goes well, this amazing telescope should perform until 2014. In the meantime, NASA is preparing to place The James Webb Space Telescope (JWST) into space in 2014, which is designed to complement the HST by seeing only infrared.
Due to stunning images from the Hubble Space Telescope and land-based telescopes, astronomers are determined to answer more questions by looking closer to unlock more “secrets” of the universe. However, extremely large telescopes are needed to see farther and clearer into the vast universe.
One particular telescope constructed on top of Mt. Graham in Arizona is called the Large Binocular Telescope (LBT) and has partners in the United States, Italy and Germany. Since human eyes have binocular vision, this telescope operates similarly by combining images produced by the slightly different perspectives of each eye. Unlike all monocular telescopes, the Large Binocular Telescope will produce three-dimensional images with depth!
The LBT will collect light from two circular mirrors that are 8.4 m (27.5 ft.) in diameter and will have the equivalent light-gathering capacity of an 11.8m (39 ft.) instrument and a resolution of a 22.8m (75 ft.) telescope! These two huge main mirrors were spun-cast honeycomb mirrors developed and fabricated in the Steward Observatory Mirror Lab (Tucson, Ariz.). The secondary mirrors will be fully “adaptive,” which means the surface of the mirror can be fine adjusted by a computer in real time to compensate for our atmosphere’s instabilities. With all parts working precisely together, the LBT will achieve angular resolutions very close to the theoretical limits even when the atmospheric conditions are not perfect. Astronomers will also combine the light from the two mirrors (called “interferometric mode”) which will achieve images with 10X better resolution than the Hubble Space Telescope. As astronomers combine the large field-size and high angular resolution, the LBT will provide astronomers with a unique facility for exploring the universe.
As of today, the Large Binocular Telescope will be the most powerful telescope on Earth… but not for long! Hawaii was chosen to build the world’s biggest telescope on top of a dormant volcano that is 13,796 feet above sea level by 2018. The telescope’s mirror will be almost 100 feet in diameter and have light-gathering ability to see objects some 13 billion light years from Earth. This will give astronomers a glimpse of the first stars and galaxies that formed some 400 million years after the Big Bang.
For more information on the Large Binocular Telescope, go to: http://lbtwww.arcetri.astro.it/LBT%20Brochure/Astronomy%20Magazine.pdf