Why is the Hubble Space Telescope considered to give the best images in the visible?
Nazdaran asked:
Why is the Hubble Space Telescope considered to give the best images in the visible when telescopes such as the Keck 10 m telescopes have almost five times larger mirrors?.
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Why is the Hubble Space Telescope considered to give the best images in the visible when telescopes such as the Keck 10 m telescopes have almost five times larger mirrors?.
March 28th, 2009 at 2:30 pm
there is no distortion due to the earths atmosphere
The Hubble is in orbit so it can see clearly into space. Keck has to deal with the distortion looking through miles of earths atmosphere.
It’s kinda like when you are looking at the horizon on a hot summer day over a long road. The wavy lines you see that distort your view are atmosphere. Same thing happens when the Keck tries to look into space.
Hope that helps.
March 30th, 2009 at 2:39 pm
Because there are no atmospheric interferences in space.
March 31st, 2009 at 3:47 pm
Any telescope in space will be clearer than one on earth
April 2nd, 2009 at 7:42 pm
There is more light in space from distant objects since it isn’t attenuated by the earth’s atmosphere.
Distortion is a problem too, but with adaptive optics most distortion can be removed on the larger more complex telescopes.
April 4th, 2009 at 10:43 am
As others have said, the Hubble has the advantage of not having to look through the unsteady atmosphere. While large Earth-based telescopes can now get higher resolution using adaptive optics, so far that only works over a very small area. Hubble images have maximum resolution across the entire field, enabling it to capture images like the panoramic mosaic of M51 released in 2005.
April 6th, 2009 at 12:30 am
The Keck 10 m telescope(s) are 20 times larger than the Hubble 2.2 m telescope, but the atmosphere interferes with their imaging.
April 9th, 2009 at 10:41 am
Injanier is correct. I’ve done a bit of work with some of the guys at the U of Arizona (which is almost in my backyard ☺) and it’s pretty easy to get images 80% to 90% as good as Hubbles up at Kitt Peak. (and they can get almost 100% as good at Attacama) But the ‘bang for the buck’ is a totally different story. Look at what it cost to get the Hubble up and running (including the Shuttle mission to fix the optics because some moron forgot to do sphericity correction) and compare it to the cost of a 16² array of fast DSP chips doing a 2-D DFTadaptive update every 50 ms or so. You can upgrade a couple hundred Observatories for what Hubble cost.
Doug
April 9th, 2009 at 10:27 pm
The Hubble can see clearer because there is no earth’s atmosphere interference. The James Webb Space telescope will be even better. It’s schedule to deploy in 2013. Check it out ->
April 12th, 2009 at 7:46 am
Although it is true that the Hubble does not have to worry about correcting for atmospheric turbulence, Hubble still does not have the light gathering power of traditional ground based telescopes as others have pointed out. Before adaptive optics, your statement about Hubble giving the best images was true, but that is no longer the case. Adaptive optics has allowed our ground based telescopes to surpass the quality of images offered by Hubble. Here is a page showing a comparison of Saturn’s moon Titan with a traditional telescope, Hubble, and then Keck with adaptive optics. The difference is clear.
The main advantage offered by Hubble now, is that it can look for wavelengths of light that are blocked by our atmosphere. Our atmosphere blocks x-rays, UV, and other spectrum as well that are only possible to be resolved from space. Hubble is only able to resolve visible light, UV, and IR; as opposed to other space based telescopes which can resolve x-rays and such.