8. Great Canary Telescope

The Great Canary Telescope is located in the Great Canary Islands.
Marco Simoni/The Image Bank/Getty Images
The Great Canary Telescope is located in the Great Canary Islands.

The Great Canary Telescope (GCT), situated on a mountain on La Palma in the Great ­Canary Islands, cost $180 million to build. It claims the title of the biggest telescope in the world, with a light-collecting area 10.4 meters (34.3 ft) across.

The telescope gathers both visible and infrared light with a mirror made up of 36 smaller mirrors. The entire 10.4-meter aperture is used at all times, making it one of the greatest cosmic observers in the world. Like Keck, the GCT uses adaptive optics to correct for the distortion caused when light passes through Earth's atmosphere. In the Great Canary device, there are several deforming mirrors, and each changes shape more than one thousand times per second [source: GTC].

With its optical systems, the Great Canary Telescope can capture distant galaxies, black holes, and planets that orbit other stars besides the sun. It can capture light so old that it shows the birth of galaxies in the earliest days of the universe.

As large as a single telescope's aperture can get, none can compare to the power of several massive telescopes working together. While the light-collecting ability of one 8.2-meter (26.9-ft) telescope might fall short of the incredible Great Canary, the capacity of several of those telescopes working in tandem leaves the GTC in the dust. That's where the Very Large Telescope comes in.