How big is your ’scope?

Contributed by
Dec 11, 2006
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... because I bet the Europeans have plans for a bigger one. A way bigger one.

They just released an announcement that they will fund a study to build a telescope that is so big that it has been informally dubbed the Extremely Large Telescope, or ELT:

European astronomy has received a tremendous boost with the decision from ESO's governing body to proceed with detailed studies for the European Extremely Large Telescope. This study, with a budget of 57 million euro, will make it possible to start, in three years time, the construction of an optical/infrared telescope with a diameter around 40m that will revolutionise ground-based astronomy.

42 meters (the actual planned size) is pretty frakking big. That's a mirror nearly 140 feet across!

To give you an idea of how ridiculously huge that is, here's an artist's conception of the observatory:

See those two dinky sticks and a longer dinky thing next to them in the lower left? Those are two people and a pickup truck (click the link to see some bigger images; they're pretty nifty).

Like I said, frakking big.

The biggest optical telescope in the world is the Keck 10 meter in Hawaii (technically, it sees in infrared, and there are two of them). The ELT's planned 42 meter mirror means it'll have 18 times the surface area, so it can see object 18 times fainter in the same exposure as Keck. It'll also have 4.2 times the resolution, meaning it will be able to separate out objects 1/4 the distance apart as Keck (so two stars that might be blurred together in a Keck image will be separated in the ELT image). It's actually a bit more complicated than that, but you get the idea.

I don't care how much it costs to build. Look at that thing! I hope they do it. That is just too cool.