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Two Eyes are Better than One
Artist concept of the fully assembled Large Binocular TelescopeHumans can see more detail with two eyes than with one. By the same token, the Large Binocular Telescope (LBT) will use a pair of eyes to allow astronomers to see giant planets that today are hidden in the glare of distant stars.

Artist concept of the fully assembled Large Binocular Telescope

Our solar system is not alone in the Universe; at least 100 of the stars that fill our night sky are orbited by planets. But these extrasolar planets are so distant and faint that they are lost in the bright glare of the stars they orbit. For now, astronomers have no way to see the planets hidden by this brilliant light.

From its vantage point at the summit of Mount Graham in Arizona, the LBT will take on this challenge by focusing on a target and using its twin telescopes to remove the star from view. In this technique, called interferometry, light from the target is received by each telescope and combined in such a way that the light waves "interfere" with each other, and ultimately cancel each other out. The resulting effect: The star practically disappears from view.

Once assembled, the LBT will resemble a face with a pair of enormous saucer eyes, gazing skyward in its quest to find faraway planets. The telescope's primary mirrors were crafted in a specially designed rotating oven at the University of Arizona Mirror Lab. The mirrors' combined resolution will be equal to that of a single mirror with a diameter of 75 feet! But despite this power, the LBT will only be able to see giant planets like Jupiter. NASA's long-range goal - the observation of Earth-size planets that could support life - will require a space mission.

In the meantime, the LBT may provide a glimpse of the mysterious worlds that surround us. Construction of the telescope is scheduled for completion in late 2005, with full science operations to begin a year later. The LBT is a partnership between the University of Arizona and several U.S. and international partners. The interferometer project is funded by NASA and managed by the Jet Propulsion Laboratory.

For more information, visit:

View the Binocular Telescope gallery at:
NASA's PlanetQuest and Kennedy Space Center