It is twenty years since the Hubble Space Telescope (HST) was launched. Though plagued by cost overruns, and a ghastly blunder in manufacturing the main mirror that had to be corrected by a Space Shuttle mission in December 1993 (which, essentially, put corrective eyeglasses on the telescope), the HST went on to do tremendously important and exciting work. The great advantage of putting a telescope in space is that it doesnt have to look through the turbulent and distorting atmosphere (think of what things look like seen through the hot air rising from a barbecue grill) and through haze and light pollution. This allows the HST to make extremely sharp images and make out very faint and distant objects. And when you see an object far away, you are also seeing it as it was a long time ago (since it takes light time to travel across the intervening space). Thus a look at the deep field is a direct look at the universe as it was in its early days.
Below, I give links to some of the most fantastic awe-inspiring images taken by Hubble. (These are found at the marvelous site Astronomy Picture of the Day). Maybe I am just a simpleton, but I dont see how anyone can look at pictures like this and not believe in God. Hubble isnt just about beautiful pictures, though. It has enormously increased our understanding of the universe. This site lists the top ten discoveries of HST. The most fundamental, I think most scientists would agree, was the discovery announced in 1998 that the universes expansion is accelerating rather than slowing down. This discovery wasnt made with HST alone, ground based telescopes were also involved. (A nice explanation of how one tells that the universes expansion is accelerating is here .) This discovery tells us something about the fate of the universe; it suggests that the universe will not eventually reverse its expansion and end in a Big Crunch, but will expand forever, getting ever colder and emptier in an sempiternal black oblivion. (Suggests, but does not proveit could be that the expansion will stop Kick Ass (2010) accelerating and start decelerating and even reverse at some point.)
So, all hail the Hubble space telescope! Enjoy the view: