Yesterday I was given the opportunity to visit the 100-metre Effelsberg telescope, which is operated by the Max Planck Institute for Radio Astronomy based in Bonn.
Located some 40km south-west of Bonn, the 40min drive to the Effelsberg takes you up into low mountains and past some beautiful countryside scenery of forests, small villages nestled in valleys and inviting beer gardens (I have yet to visit a telescope that is located in an un-inviting region. Smart, these astronomers…)
It’s only been toppled since 2000, when that title passed to the Green Bank Telescope operated by NRAO in West Virginia (with only a slightly larger collecting area).
The Effelsberg titan weighs an incredible 3200 tons, which are moved seamlessly and at impressive speed to point the telescope. Indeed its 16 electrical engines of 17.5kW each can accomplish a full rotation in 11min, and move with an accuracy of less than half a millimeter…
Half a millimeter is also the surface accuracy of the 2352 aluminum tiles that compose the collecting surface of the dish. That means the largest imperfection on this 9090m2 area is less than half a millimeter tall…
By the way, for scale on the photo, the secondary mirror (the tiny little one that sits just under the junction of the four arms), measures 6.5m in diameter, so you can fit more than 3 people horizontally there.
Today the Effelsberg continues to do great science and is still oversubscribed – meaning there is more demand from astronomers to use it than time available on the telescope.
I would call this a very fine example of German engineering indeed.
For more information visit the Max Planck’s website.
*There are larger fixed radio telescopes like the 300m Arecibo which sits in a natural valley in Puerto Rico (another fine location) but that takes away a lot of the engineering *fun* of designing it doesn’t it…