Does anyone know where I can get a powerful space telescope with a 20" mirror?
952358
Here is a site that gives you several sources for 20" telescopes.\nhttp://www.bigtelescopeguide.com/20-inch-telescope-mirrors.html
1143611
Well, first off avoid the TASCO ones 'cos they have a reputation for using cheap optics with overly powered eyepieces (according to those in the know) - I bought one myself off Ebay a couple of years ago.\nIt ain't exactly bad (apart from the wobbly stand, cheap eyepieces, hopeless spotting scope)...... more stupid but savable than bad. Couple weeks ago I finally got round to buying a better quality "Orion Explorer II 7-21mm Zoom" eyepiece, which is a good investment, but the usual New Telescope/Accessory + sky gone cloudy once it's dark enough outside to use it jinx has been occuring ever since I got the blinkin' thing!\n\nLooking @ Telescopes.com, within your budget I'd suggest...... *drum roll*....... \nthe \nCelestron - FirstScope 114 EQ Short Newtonian Reflector  @ $159 (knocked down from $377)  http://www.telescopes.com/products/Celestron_FirstScope_114_EQ_Short_Newtonian_Reflector_5936.html\nor the Meade - 114EQ-A Short Tube EQ Reflector @ $179.95 (knocked down from $249)  http://www.telescopes.com/products/Meade_114EQ-A_Short_Tube_EQ_Reflector_-_Deluxe_Mount_42684.html\n\nAnother alternative is to scour the adverts in the back of Astronomy magazines for ones people are selling off..... or of course good old Ebay\n http://photography.listings.ebay.com/Binoculars-Telescopes_Telescopes_W0QQfromZR4QQsacatZ74927QQsocmdZListingItemList\n\nFor more advice, check out:\nhttp://skyandtelescope.com/howto/scopes/
900039
A dobsonian telescope will give you the most telescope for your money. These are Newtonian reflectors on simple alt-azimuth (tilt & swivel) mounts. Get as much aperture as you can afford and handle. More aperture means being able to see fainter objects and finer detail. Many people find an 8" scope a good choice.\n\nOrion Telescope & Binoculars has some good beginner dobs. Zhumell is another brand with good values in this area.
869588
A good mid-priced porro-prism binocular such as the Orion Vista will be good enough for most people. If you want the best, look into the Nikon Prostar or Fujinon Polaris binoculars.  The Canon image-stabilized 15x50 is another good, premium astro binocular.\n\nMany of the lower-priced models from Orion, Celestron, and others will do fine. You'll get a little more distortion towards the edges of the field, and maybe a little less light throughput in the cheaper bins. For astronomy, you can dispense with extras such as rubber armor, weatherproofing, and center focus. Porro-prisms are better for astronomy than roof prisms, because the roofs can show a bit of a spike on bright stars. Avoid models with polarizing or anti-haze filters or coating - fine for daytime use, but their light throughput is considerably reduced.
996119
Nice to see an Indian on here!! I'm an Indian too! Maharashtrian and mainly from Pune city. Yeah, you can get telescopes in India and the prices do vary dependent upon the power it has. An average telescope that can allow you to study the solar system in a glance is available at Rs. 7000. I saw one in an exhibiton, but sorry can't really specify where you can get it. Give me your mail id and if i find anyone selling it, I'll give you the whole details. why don't you make one?? that's a great idea, cause i have made one myself that is as cheap as Rs. 500!!
20264
Try http://www.nasa.gov
32162
C is true. The others don't really make sense.\nThey are also inherently chromatic, more efficient. Even small ones are cheaper for the size than refracting. \nHubble Space Telescope is reflector also it will work with Ultra violet light, and more precisely focuses than glass can.
837333
If you want good data and you are not trying to observe something that is temporary like a comet, I highly recommend skyview. You don't get to steer the telescope and see real time images, but there are some great surveys in many different wavelengths there.\n\nhttp://skyview.gsfc.nasa.gov
902786
Imagine how hard it is to try to teach High Schoolers anything about the planets when one of them has a name like this! But anyway, go to NASA's website. There is a place there where you can find anything worth seeing at any location. It will even tell you when stuff like the Space Station will fly overhead. And most telescopes come with locating software if you ever get that involved. I hope you will. It seems like we never learn much about space, but it has taken a long time to get as far as we are now.
111046
The Bradford telescope at the website below is the best:\n\nhttp://www.telescope.org/
590111
Try http://www.surplusshed.com/pages/item/t1423.html\n\nHowever, you are going to be *very* disappointed with the view quality.\n\nThere is no way to turn a camera lens into a "high quality" telescope. Telescope objectives and camera lenses are made for different purposes and to different standards. A camera lens can get by with poorer quality of image because the image is not going to be magnified 200x by an eyepiece. At the same time, a telescope doesn't need to project an image that is flat and large enough to cover the fil, size.\n\nIf you really want a telescope I have two different suggestions to try instead. Go to astromart.com and watch the used telescopes. But the best suggestion is to go to http://skyandtelescope.com/resources/organizations/ and find your local astronomy club. They will have public nights. Go to a public night. You will get to look through a lot of different telescopes. By the end of the night you will know what you want. And, you are likely to come across a very good deal from someone who wants to sell their telescope and upgrade.\n\nhttp://groups.yahoo.com/group/lunar-observing/\n\nChuck Taylor
798548
That price range is difficult...You're honestly better off buying a pair of astronomical binoculars at that price.  If you're willing to go to $230, though, you should check out the Orion XT4.5....or $260 to get the Orion XT6.\n\nWhatever you do, *don't* buy a telescope based on magnification. If a telescope brags on the case it can go "up to 500X!", it's most likely junk with poorly made optics.\n\nIf you really do want to get a telescope, a lot also depends on how manual or automatic you want it to be.  On the manual side, if you're willing to learn the sky and adjust the telescope's optics (known as "collimating"...not as hard as it sounds, really), you should go with a dobsonian, which is essentially just a big light bucket you push around.  On the automatic side, if you want to just align on a couple stars and type in an object to make the telescope move there itself, there are the "go-to" mounts, such as the Meade ETX-60 (runs about $240).\n\nDobsonians ("dobs") such as the Orion XT4.5 do require you to manually know where to point the scope, and objects will slowly drift across the image due to the Earth's rotation.  The Meade ETX's will track so objects don't drift...but all this automatic stuff comes at a price - the main mirror on the ETX is only half the size as the one on the XT4.5, meaning your resolution is only half as good and your light grasp (the dimmest object you'll see) is only one-quarter as good.  So while Saturn's rings should be visible in the ETX60, they'll look a whole lot better in the XT4.5.\n\n Also, you'll need to buy a separate tripod for the ETX...the dob just sits on the ground in all its bucketness.\n\nYou might also want to set aside some cash for a good eyepiece and a barlow ($80 or so), or upgrade over time.  The eyepieces that come with most scopes are not so great, and the barlow will come in handy to double or triple the magnification on nice still nights.
491826
Pretty much any telescope will see 'to' Uranus. Occasionally it can even be seen without any optical aid. That said, do not expect to see more than a small blue dot, even with a fairly big scope (one past what you are willing to pay).\n\nGenerally speaking, refractors are better for planetary viewing because they allow a higher magnification (longer focal length). The problem is that they are subject to chromatic abberation (little rainbows around bright objects) unless you spend a lot to correct it with good quality lenses. Reflectors will more often have spherical abberation, which tends to blur out features, so they tend not to be as good for planets.\n\nNext, are you talking about just the telescope or is the $600 for the telescope AND eyepieces? The right eyepieces can make a huge difference, so don't neglect them when shopping. For planets, get a couple of medium to high power Plossl eyepieces.\n\nBelow is a site with some good refractors. Disclaimer: I am not in any way affiliated with Orion Telescopes.
982426
That depends what consideration you have.  Reflecting have the advantage of having less chromatic aberration than refractor, and tend to be larger for a given weight.  The most important aspect for a telescope is the size of the primary mirror, because it defines the light gathering capability, so this is a case where bigger is better (as long as the quality is there, evidently)\nCassegrain is a variation of the reflector, where a secondary mirror sends the light back through the center of the primary; the other style is Newtonian where a diagonal mirror sends the light t the side.  For moderate size telescope Newtonian is more comfortable.\nA very important aspect to consider is also the mounting.  If you only want to do optical observation, then a Dobsnian mounting is very cheap, as it forgoes the tracking mechanism.  If you would want to do astophotography with long exposure, then you would need an equatorial mount with a drive that can track a star.  Recent models rely on computerized motorization, which as most electronics, have allowed the advanced capabilities for an relatively acceptable price.\nMy suggestion is that you document yourself, perhaps buy a couple of issues of astronomy magazine, like Astronomy or Star & Telescope, and get acquinted with the market.  You will be able to decide what you want, and what you can afford.\nAnd I hope you have access to clear sky and dark night.\nHappy observations!
713708
Maybe you could make use of a giant mirror orbiting directly above you geostationarily in space.\n\nSo you could see your house... from the sky. :)
850965
http://en.wikipedia.org/wiki/Keck_telescope
890617
Small observatory class telescopes can be as cheap as tens of thousands of dollars. The Keck telescopes, which are among the largest in the world, cost $94 million and the Hubble Space telescope, which is actually smaller, cost $1.5 billion.