Waiting for the James Webb Space Telescope
The Hubble Space Telescope has arguably been one of the most successful scientific experiments in history. It has produced (among many other things) images of galaxies when the universe was only about half a billion years old (it is now 13.8 billion years old), and has given us a glimpse into the actual composition of the atmospheres of extrasolar planets. Hubble's scientific successor, the James Webb Space Telescope (JWST), will literally infuse new meaning into the phrase "the search for ourorigins." It will show us the very first galaxies to have formed in our universe, and will identify those extrasolar planets likely to have liquid water (and therefore origin-of-life ingredients) on their surface.
The James Webb Space Telescope (Figure 1) represents an ambitious international collaboration led by NASA, with the important participation of the European and Canadian space agencies. The machine itself is nothing short of a marvel, with a gold-coated beryllium mirror 6.5 meters in diameter (Figure 2). The mirror itself is composed of 18 hexagonal segments, which will unfold, origami-like, after the telescope is launched. Since the light from objects in the distant, early universe is significantly redshifted, JWST will observe in infrared light. In addition, the ability of infrared radiation to penetrate through dust and gas (which are opaque to visible light), will allow JWST to peek into regions where new stars and planets are born. The telescope will be equipped with a tennis-court-sized sunshield that will unfurl and protect it from radiation coming from the Sun, Earth, and Moon (Figure 3).
Unlike Hubble, which is in a low-Earth orbit at a distance of just over 300 miles above the surface of the Earth, JWST will be about a million miles from Earth--about four times the distance between the Earth and the Moon.
Perhaps even more importantly, however, we have to expect the unexpected. More than half of the major discoveries by the Hubble Space Telescope were not anticipated. I expect nothing less from the James Webb Space Telescope! I cannot wait for its launch in 2018.
http://m.huffpost.com/us/entry/4151427
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