Learn about the importance of space telescopes. Also learn about the optical interferometry technique of getting sharper images of space.
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The Importance of Space Telescopes During recent years, we have all enjoyed a flurry of stunning pictures of distant stars and galaxies. For scientist such images provide new insights into the nature of celestial objects and there by into the physics that determine their appearance and evolution. The sharper the images are the better. This is why telescopes like the ESO very large telescope and the Hubble space telescope are so important for scientists. Already long ago however, astronomers realized that by using a special method called optical interferometry, they might be able to study their objects with much higher precision still. The only problem was that optical interferometry is exceedingly difficult to master. Interferometry requires the light from two or more telescopes to be combined. The Paranal Observatory in Chile, home of Europe’s very large telescope, the most advanced ground based observing facility in the world was conceived as an array of 8.2 meter telescopes. It was designed to work as an interferometer. But it meant doing interferometry on a scale never attempted before with a by astronomical telescope. In March 2001, ESO carried out the first interferometric tests observations with great success. Since then, the experience of work on refining the technique, while at the same time adding new specialized telescopes to the array. The new telescopes are 1.8 meter telescopes that unlike their larger brothers could move around on a system of rail tracts. This way the distance between then can be varied according to the needs for individual observations. By observing the same object with different telescope configurations, it is possible to obtain images that are 100 times sharper that what can be observed with the Hubble space telescope. Only of these special so called auxiliary telescopes had been delivered to the Paranal Observatory up until a few years ago. Now however ESO has commissioned its second one. This means that interferometric observations could be carried out continuously without interrupting observations with the main telescopes. But the real importances of these additional telescopes lie elsewhere. The VLT interferometer will allow astronomers to study details on the surface of stars or to probe proto planetary disks and other objects for which ultra high precision imaging is required. It is premature to speculate on what the very large telescope interferometer will discover but it is not difficult to imagine that there maybe quite some surprises in store for all of us.