can anyone tell me about telescopes.?
99180
Mostly cost. Making perfect lens gets more and more expensive as the lenses (3 in a good refractor) get bigger.\n80mmm = $1000 160mm = $10,000 200mm = 50,000. The really big ones, like 30 inches, also have such long tubes, it gets very expensive to build a mount for them.\n\nreflectors have only mirrors, no lenses.  much easier and cheaper to make. Since light does not go "thru" the mirror, you don't have to have perfect, expensive glass. And all colors (red, blue, green) come to focus at the same point. Not true with lenses.\n\nHawaii is not only above the clouds and the polution, it is also above the weather, so the air from the top of the mountains out to space is much calmer. From sea level, the air "boils" with all the wind layers, and distorts the image seen throught telescopes.
214155
I am gessing that you want to knoe about "optical" telescope.\n\nThere are basically two types of optical telescopes.\n\n1. Refrective Telescope\n==========================\n\nThere is an objective lense that creates a virtual image of the object you are trying to see very close to asecond lense called the eaypiece. The eyepiece magnifies that virtual image many times bigger.\n\nMagnification = focal length of objective/focal lenth of eyepiece\n\n2. Mirror type (Newtonian)\n==========================\n\nThis type uses a parabolic mirror to create a virtual image of the object you are trying to see very close to the eaypiece. The eyepiece magnifies that virtual image many times bigger.\n\nMagnification = focal length of mirror/focal lenth of eyepiece
976467
http://www.c2gr4s1r.com/results.php?keyword=Setup+For+A+Bushnell+Telescope+78+3650
121596
You don't send radio or x-ray, you measure them coming from the objects in the sky. The telescope is the instrument to collect this waves and concentrate them. Just as a common telescope receives light, this instruments receive other wavelenghts such as the mentioned above, which are produced and send by the objects.
167535
If your telescope has a finder scope (a much smaller telescope mounted on the main telescope) stick with observing objects that you can locate in it. In order to observe more distant objects that you can't see with either your naked eye or the finder scope, you'll need to learn about the celestial coordinate system (right ascension and declination) There are hundreds of fascinating objects that even smaller telescopes can bring into your vision, but can't be easily located without knowing their celestial coordinates and how to locate those coordinates.
799829
Looks like you need to read the documentation on the website.  Is does say that it's all simulation mode for now, so you're not actually controlling the telescope yet.
294452
Optical telescopes gather visible light and magnifies the image for visual clarity and optical analysis.\n\nOptical telescopes use lenses and mirrors.\n\nRadio telescopes gather radio signal emmited by extraterrestrial bodies and amplify them for analysis.\n\nRadio telescopes have antenna.\n\nRadio and optical signals are both electromagnetic in nature covering different frequency ranges in the spectrum.\n\nRadio waves cover a much bigger range of electromagnetic wave frequesncies -- thus a provides a lot more information for analysis.
98059
The short answer is: No one really knows, since the details are classified. Also, the current satellite performance is probably not as good as what it CAN be. \n\nI think that comparing what astronomers are able to do with what the best satellites are able to do can be a bit misleading. \n\n1. The space telescope does not have to look through the air, with the water vapor and turbulence and dust. The space telescope has only the very outer reaches of the atmosphere to look through. \n\n2. The space telescope and ground-based astronomers do not have at their disposal anywhere near the resources that governmental organizations do. For example, the space telescope was not even calibrated, because there was so little money! It was only because of heroic efforts and a few minor miracles that the space telescope was brought into focus. The space telescope is basically a toy, and has barely been able to get funded for the last few years, and might be soon decommissioned. \n\n3. Astronomers just do not have the interest, the background, the training, the knowledge, or the resources to command the type of bleeding-edge technology that governments do. Astronomers for the most part are mired in phenomenology, and do not worry much about the details of pedestrian things like optics. Optics is, in general, disparaged by astronomers and left to the "engineers" and other lesser beings like mathematicians, physicists, statisticians, computer scientists, etc. Basically, astronomers hurt themselves with their attitudes and their culture. \n\n4. No responsible government is going to announce what they are capable of seeing with their satellites. All of this material is very closely held at best, and most likely highly classified. \n\n5. It is well known (or at least often reported in the newspapers, so it might not be correct) that spy satellites are so big and so heavy because they bring a large reserve of fuel with them so that they can be lowered and raised as needed to see various features and details. Apparently, they do not always orbit at the same altitude. \n\n6. It is quite possible to combine imagery from platforms such as multiple satellites, planes, high altitude balloons, etc. to improve resolution considerably. It is hard to know the extent to which this is done, or if it is done, because of course the area is shrouded in secrecy, so we do not know. But the question was, how detailed CAN it be? Well you COULD use multiple sensors on multiple platforms, unlike the Hubble telescope (in fact, multiple sensors on the ground are able to beat Hubble now). \n \n7. As a gross upper bound on resolution limits, look at the mutually agreed upon limits on size of warheads etc by the Russians/FSU/USSR and the USA, for example (typically, the silo doors would reportedly be opened to permit treaty inspections, according to newspaper accounts anyway). These specifications in the treaties imply MUCH higher resolution than the some of the numbers given here by others. And remember, these are the mutually agreed-upon resolutions by two very suspicious adversaries, who do not want to give anything away. Both have to be able to achieve these resolutions, and probably are capable of far better resolution. \n\n8. Having looked at Dawe's limit, and knowing a bit about resolution, I can tell you that it is not particularly useful as an indicator of achievable resolution. How close we are able to come to ultimate resolutions depends on how many resources we are willing to spend, and again since it is classified, it is difficult to know.\n\nTherefore, to answer the question how detailed can satellite imagery be? The answer is, VERY. How detailed is it? We do not know, since it is classified.
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.
405723
Most modern telescopes come with a guidance computer. You can just enter the name of the body you're looking for and the telescope will adjust accordingly. \n\nIf you don't have one of those, the best thing to do is follow the course of the sun. Planets are on the same plane, so they will more or less follow the same path that the sun does. \n\nExcept Pluto. He's just nuts.
254369
Ahhhhhhh...A fledgling Amateur Astronomer!!...WONDERFUL!!\n\nThe first and foremost thing to consider is APERTURE..This is the SIZE of the opening of the telescope...The reason is, except for the moon, astro objects are dim...the larger the aperture, the more LIGHT will be gathered and focused into your eyepiece, so the clearer the image and the higher magnification you can use without blurring.\n\nYou mention a price range of $2000...That much money will buy a GREAT telescope, however, I suggest you start with a less expensive Dobsonian telescope for your first purchase.\nThis will give you some experience, HOURS of enjoyment, and will let you see if you are REALLY interested enough to upgrade to a more expensive piece. Dobsonians ( or NEWTONIAN...Same principle, REFLECTORS ) of good quality can be purchased on E-bay for around $300-$500.\n\nIn the $2000 range, look for a 'Schmitt-Cassegrain' with ' Go-To' electronics...Readily available
860328
No,\nI wouldn't say that's entirely impossible but it'd be a small technical challange.\n\nIf you can't afford a telescope you should contact your local astronomical society. Many will let members borrow telescopes for free or they may be able to tell you of a star party where you can go and others will let you look through their 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!
828006
It's a great toy. A 60mm aperture (2.4") won't gather much light (which also determines the amount of detail you can make out at higher magnifications). Is this a refractor? Cheap models suffer from various distortions produced by inferior coatings, poor collimation, etc.\n\nYou can see a long way (moon, mars, stars, etc), but thre real question is how good the image is (fuzzy, dim, etc)\n\nTry the following website (page goes to a celestron 760 mm refractor - a decent instrument. Lots of description.)\n\nhttp://www.telescope.com/jump.jsp?itemID=116608&itemType=PRODUCT&path=1%2C2%2C4%2C13&KickerID=699&KICKER
58101
Simple: http://www.life.uiuc.edu/hughes/boast/sciencelessons/telescopes.htm\nAdvanced: http://www.funsci.com/fun3_en/tele/tele.htm
354230
Greetings,\n\nFollow this link to Sky and Telescope magazine's website almanac.  Plug in your information and it will give you the info you requested.\n\nhttp://skyandtelescope.com/observing/almanac/\n\n-matt
791471
The biggest thing you need to know is how interested in astronomy is the person getting the gift. If they are then by all means buy the gift.  Either Meade or Celestron make great scopes for under how much you have to spend. Either cassigrain or refractor  will do what you want.  Both sites will explain how each one works and give list prices.  Most retailers sell for under list price