Radio Telescopes
Posted in Telescopes on July 15th, 2010 by admin
The Sun and stars emits radio waves — not just visible and infrared light. In the 1930s, Karl Jansky built the first devise to “listen” to the sun, collecting radio waves from far off stars and focusing them onto a detector. This invention provided astronomers with a completely different view of the Universe — prompting the discovery of radio stars, quasars, and black holes.
This video features a model of the Algonquin Radio Observatory (ARO), located in Ontario’s Algonquin Provincial Park. In 1968, astronomers combined signals from the ARO with those from the Dominion Astrophysical Radio Observatory in Penticton, British Columbia forming a new instrument called a Long Baseline Interferometer.
To learn more about Astronomy and Telescopes, visit the Canada Science and Technology Museum.
http://www.sciencetech.technomuses.ca/
Duration : 0:3:7
In principle, the larger a telescopes mirror, the finer the details it can see. Continuing to increase the size of telescope mirrors is not an easy task, so astronomers have come up with a new technology to see even finer details: interferometry. This observational technique combines the light received by two or more telescopes and allows them to act as a single unit with a mirror diameter equivalent to the distance between the telescopes. Engineers designed the VLT so that it can also be used as an interferometer. Along with the four 8.2-metre Unit 
Every night, all year round, the ESO Very Large Telescope, or VLT, opens its four giant eyes to scrutinise the beautiful southern skies. Each eye is a huge mirror, 8.2 metres in diameter, that gathers the light of the night sky, and reflects it into optical systems that form ultra-sharp images of the Universe. But keeping the VLT’s eyes clear requires each mirror to be cleaned and recoated occasionally, a delicate and complex procedure.