A High-Resolution View of the Universe | Features | Nov 2016 | Photonics Spectra
http://www.photonics.com/Article.aspx?AID=61165
Even the best astronomical sites in the world, located on remote mountaintops with particularly stable air,
degrade diffraction-limited images to 0.6 to 0.7 arcseconds. While this is approximately 100 times finer than
the naked eye can achieve, it is no better than the diffraction limit of a modest backyard telescope.
Space telescopes do not suffer from the limitations imposed by atmospheric turbulence. The 2.4-m-diameter Hubble
Space Telescope can produce images with detail as fine as 0.04 arcseconds in visible light. The 6.5-m-diameter
James Webb Space Telescope, due to be launched in 2018, will have nearly three times higher resolution in the
infrared, but its mirrors are not specified to achieve the diffraction limit in the visible.
