A
astrosite
Guest
Hi, I'll plan to get fancier (HTML, etc., later). Right now, BTW, I can only logon to space.com from public library computers; my home computer never comes back if I try to register as a user here.<br /><br />Anyway, to my main point:<br /><br />The first time I saw the Moon through a REAL amateur telescope, an eight-incher, I was totally blown away! It was like being on Apollo 8, cruising over the Moon's surface, or at least on approach to the Moon.<br /><br />Sometime later, I asked a knowledgable amateur astronomer and friend about what size of scope it would take to see Mars like that. His initial answer was off due to him having to do an improptu calculation in his head. But he gave the right idea: mulitply the aperture of an 8" by how much further away Mars is than the Moon.<br /><br />I've been thinking about that ever since. The scope would have to be hundreds of feet in diameter. But since then, I've also learned about interferometry. You can effectively have the aperture of a huge scope by just having two (regular) mirrors that far apart. The trick is, you have to get up an interference pattern, indicating that both mirrors are aimed at the exact same point in the sky at the exact same time. Other problems include atmospheric turbulelence and the dimness of the image (a filled aperture would give an appropriately bright image, of course). Then you have to use computers to analyze the interference patterns, assuming you can even acquire these patterns as desired. Professional astronomy uses interferometry and active/adaptive optics to counter the effects of the atmosphere and the imaging system's local environment (heat, moisture, vibration, etc.).<br /><br />But this interferometry is very hard, even for professional astronomers. Nevertheless, I think that interferometry, adaptive/active optics, and other necessary techniques can be brought to amateur astronomy. You know how at star parties, amateurs are standing around and using and talking about their twelve inch