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Giant Telescopes Of The Future
mindpixel writes: "Mindjack just published my article about the the future of very large telescopes, such as the VLT and the OWL which I talked about in my /. interview. In addition, I talk about a future space-based telescope that would use the Sun's gravity to 'image large surface features,' of extrasolar planets, which telescpes like the VLT can just detect, 'such as oceans, continents or ice caps, or even the impact of civilization on such features.'"
The only real question for OWL is money, and the only one for the solar foci probe other than money, is the controversy surrounding placing a nuclear reactor in orbit.
Ah! It's so simple. All we need is money!
With the budget cuts at NASA, I don't think either one of these ideas will take off. (no pun intended)
D/\ Gooberguy
Karma: Meh (Mostly from meh.)
One reason I understand for having Hubble in space is the fact that diffraction of light from the atmosphere and maybe even minute seismic vibrations from the earth would distort the picture for a large telescope. Does anyone know from close we are to the point where larger land telescopes will be made impractical be these phenomenon?
I stole this Sig
I remember seeing on either "The Planets" or "Stephen Hawking's Universe" documentaries, mention of plans (prolly drawingboard stuff) to place an array of hubble like telescopes past the asteriod belt to create a VLT in space...
I'm curious to know - because of the limited size (surface area) on earth (which cosmologically is a pinprick in space) what kind of performance increase would one get by placing those telescopes in space and would it be a better move in the long run?
-- Dan =)
'such as oceans, continents or ice caps, or even the impact of civilization on such features
You think we've got global warming problems just because our ice caps are melting? Go talk to the aliens over on Alpha Centauri, they've got so much global warming that their continents are melting!
Tarsnap: Online backups for the truly paranoid
After all we know that the universe is around 6,000 years old so you don't need a very big telescope, and anything that looks older is wrong so you don't need funding.
This announcement was brought to you by the State of Kansas Research Funding Department.
:-)
An Eye for an Eye will make the whole world blind - Gandhi
The solar foci telescope idea sounds really cool, but it's got a big limitation. It can only see in 1 direction. With a 450au orbit, its orbital period is around 9500 years. That means it will only move 0.037 degrees through it's orbit every year. And assuming it won't be carrying the fuel to make huge orbital adjustments, it will only be able to view along the plane of it's orbit. We would have to have a good dense area of sky to view before launching something like that. :)
The solar foci telescope idea sounds really cool, but it's got a big limitation. It can only see in 1 direction. With a 450au orbit, its orbital period is around 9500 years. That means it will only move 0.037 degrees through it's orbit every year. And assuming it won't be carrying the fuel to make huge orbital adjustments, it will only be able to view along the plane of it's orbit. We would have to have a good dense area of sky to view before launching something like that. :)
Space as some of you may know, it not all that empty. How long would this thing last before something the size of a golfball tore it a new asshole? And then, who the fuck is going to go fix it.
A very silly silly idea. Just wait a few 100 years. Thats all.
What the fuck it the rush anyway??
jebus
A very readable article, but I was surprised to see no other information on the referenced large telescopes. To save others from searching as I did, take a look at:
LL
The solar foci telescope sounds like a really interesting idea but I'm not sure it's all that practical now or in the near future. 550 astronomical units is really far out there, several orders of magnitude further then any other space mission to date. Combine that with the proposed size of the mission spacecraft, again vastly larger then anything previously done, and I don't see this happening anytime soon. Still, a very interesting idea though and a logical extension of using extra-galatic objects and looking for lensed objects behind them. Just a few years back that was 'never been done before' stuff too so who knows. In any event, I have to give credit to whomever came up with this idea, they certainly think big!
More information on the solar foci idea can be found on this page from the Texas Space Grant Consortium.
You can get books telling how to make telescopes from Willman-Bell and ask for help on the Amateur Telescope Maker's mailing list. Dan Cassaro can sell you a reasonably priced mirror grinding kit.
You can find many products for amateur astronomers at the Astronomy Mall.
Clear Skies!
-- Could you use my software consulting serv
$title =~ s/Telescopes/Robots/; :)
Free Java games for your phone: Tontie, Sokoban
So some sicko can check out alien girls somewhere out there?
Would it be possible to use ordinary parabolic satellite TV antennas for radio telescopy? Could they be combined to create a huge radio telescope?
If that's possible, maybe when people are not using their satellite antennas for TV they could be combined to create a world-wide radio telescope.
I'm thinking of something along the ideas of SETI@home. There, the unused computer time of many people is combined for the SETI program. Maybe unused satellite TV antenna time could be combined in a similar way.
To create a large and powerful telescope you combine several smaller telescopes. There is an enormous amount of unused TV antenna time. If ordinary satellite dishes are suitable for this purpose, you'd get an extremely powerful telescope.
Give a man a fish and he eats for one day. Teach him how to fish, and though he'll eat for a lifetime, he'll call you a miser for not giving him your fish.
Terrorists can't threaten a country's freedom and democracy. Only lawmakers and voters can do that.
So it's only a matter of time til we really do have the smell-o-scope :)
I don't know much about optics (other than the math trips me up and I hate it,) but instead of sending a space craft 550au away from the sun, couldn't you position a craft a tad closer? albeit it would have to be significantly larger a craft. I'm thinking a giant ring that intercepts the light between the lens (sun), and the focus. Or maybe not even a ring...again I don't know much about optics, but couldn't you still get a magnified image just by being in the path of the light? Even if it's not the entire picture, it could be useful.
just my misguided two cents.
--Roy
Look at the second and third generation space telescopes from the "Origins" program.
Get off my virtual lawn, you damned virtual kids!
If your interested in this have a look at quite a few other plans in the works, many not so far off (2004 and beyond) for new telescopes looking for extra-solar planets and such.
For example the Terrestrial Planet Finder (TPF) which although is currently un-funded, is targeted to launch around 2011.
More links and info.
These kinds of advancements make me happy to be alive now, and I look forward to 'seeing' the first "earth like" plannet!
If you can get an array with a long enough baseline, and high precision in positioning, you can do interferometry with space telescopes. In principle that could give you enough resolution to spot small planets around nearby stars. JPL is currently studying a space interferometry mission, to fly by 2009, which will fly a small interferometer to demonstrate the potential of this technique.
Toronto-area transit rider? Rate your ride.
Has already become a factor in how big telescopes can be on earth. But, it's already been "fixed", too. The new giant scopes use adaptive optics that actually compensate for atmospheric distortion in realtime.
To me, that is simply amazing. Adjusting 1600 mirrors realtime to correct tiny air currents!
Let's see: 400 tons is 800,000 lbs and at NASA's goal by 2025 of $100/lb that is $80,000,000. That's just launch costs alone. Ouch.
BUT................. All that crap was written by you, and your loser friend. Isn't it time you made your own site where you can get first post, every time, all day.
Microsoft - Where would you like to go today, Maybe Jail?
This distance is immense and would, if stationary, use the solar ecliptic as a reference. Even further.
A 100+ redundant system would be cheap over a self fixing system. Let's go! A B.F.A.A (Big Fuckin' Ass Array) would solve many philosophical questions. Artificial light on a far away planet? Bring it on!!!
The moon, however, has neither of these problems. It doesn't have any seismic activity that I know of, and there is no atmosphere to hinder a telescope.
From what I gather (I don't know nearly enough about this stuff) you don't actually need to build a giant telescope on the moon for this to work. You can build an array of smaller scopes and link them together to see a giant field. Since the moon has no seismic activity all of the small scopes effectivly function as one giant one, that we can focus onto anything we'd like, including extrasolar planets.
Since these are smaller telescopes (not tiny, but smaller than some of the giant things we've got on earth), we can use traditional spacecraft to get them to the moon. Of course it'll cost a lot, but would make the Hubble look like a child's toy when it's finished. The question is, are we willing to head back to the moon, and do we really feel that the search for life is this valuable?
Robert Zubrin wrote a good book about this, "Entering Space", which is where I got most of this moon-telescope information. My copy is back at my dorm in Arizona, so I can't quote exactly, but I think I've given the basics. A site that may also be helpful is Here (A little to much math for my tastes, but maybe some of you guys can figure it out)
Charlie
The same gravity lens effect would occure for the earth, or even the moon. This would be a more pratical approch, considering our level of technology. In addition, it would orbit much faster, and would be easier to move, than a solar foci telescope.
What is the focal length for the earth anyway?
Could a space-based array be designed so that once it reaches its target location, it spreads itself out, gradually increasing the distance between its elements in a coherent manner, thereby increasing the effective size of the array over time? I would assume that a space-borne array would already be designed with plenty of fuel/rocketry for compensating for massive objects passing nearby and tugging on its corners... The same principle might be handy for adjusting/balacing the spacing between elements if an asteroid hits the jackpot, or a failure is detected.
:).
Yes, but you'd be trading off angular resolution against aliasing artifacts (the less of your aperture is filled, the worse aliasing artifacts will be, even when you assume constant sources and integrate over time). IMO, you'd be better off just adding more satellites
By coincidence, I recently did the calculations for the size of a metre-band radio telescope array needed to resolve features 100 km in size at a distance of 10 light-years (enough to resolve the aurorae of earth-sized planets, show thunderstorms on gas giants, and so forth). You'd need thousands of radio telescopes in solar orbits out to a radius of about 4 AU, but you could do it. Put them in eccentric polar orbits (i.e. away from most of the junk in the ecliptic), add excellent GPS-style beacons in precisely known orbits (constantly observed from Earth) to let the satellites track themselves, and you could get a very nice radio telescope for a surprisingly modest price (cheap satellites, well-known technologies and electronics, and the benefits of mass production, since you'll be making a thousand or more of them).
Such a telescope would be able to see aurorae and civilization-induced radio junk from Earth-sized planets out to around 10 light-years, map the magnetospheres of Earth-like planets and see detailed magnetic features in gas giants out to about 100 light-years, and get very detailed pictures of the outer envelopes of stars out to about 1000 light-years. It would be a very useful project.
From what i remember reading, that's not at all true, since their are no techtonic plates on the moon, the only thing that causes any sort of seismic activity are tidal forces and impacts. But not very large quakes neverless, like 4 on the richter scale.
Apparently, for you, that is a big achievement. Not too many times, mind you, that would be too much effort, but a few times anyway. (I think my karma is still better than yours, though, for what it is worth.)
Microsoft - Where would you like to go today, Maybe Jail?
Space is math. Fucking orbits, gravity, velocity, gas. Lots a GAS! All that BORING BULLshit. Someone build me a god damm space shit so I can go blow some planets up in shit...!
Work hard you fucks becuase you pasty-ass faggots are NOT the jocks who are gona fly those fuckers...no way! Thats job is for people like me....people who know what OUTSIDE looks like! People who get pussy!
So hurry up you fucks! Stop dreaming about 7 of 9 and get your ass to work on my spaceship! I wanna blow shit up!
Fist thing I do on the test run is blow up that fucking hubble thing......! Stupid nerd telescope! ONLY nerds would design a telescope that NEEDS glasses to work! Idiots.
You weak fucks...! Get some pussy Dammit! Do you not know what wonders await you between a womans leggs? Fuck man.....you lot would never look at space again! Fuck the universe man.....pussy!!
Jebus
Would it be possible to use ordinary parabolic satellite TV antennas for radio telescopy? Could they be combined to create a huge radio telescope?
If that's possible, maybe when people are not using their satellite antennas for TV they could be combined to create a world-wide radio telescope.
You could in principle do this, but in practice there are problems.
The main problem is that the electronics in the detector used with the dish are completely unsuited to radio astronomy. To use a radio telescope as a part of the array, you need a high-fidelity sample of the radio signal being received, timestamped to atomic-clock accuracy. A satellite TV pickup doesn't have a sub-nanosecond-accurate clock, and won't give you a digitization of the raw signal. Instead, it looks for strong signals in specific, narrow bands and blindly decodes them through combined analog and digital means (i.e. it treats everything it hears as a TV signal).
A secondary problem is that your satellite dish is pointed directly at a strong source of radio noise in the frequencies it's tuned to detect (the satellite).
The idea is a great one, but because you'd need to completely replace the electronics rig with something far more expensive, a better approach might be to sell radio telescope array "kits" built from stock parts and forget about using peoples' TV dishes.
This would probably be quite practical from an engineering standpoint, as most of the parts (including timestamping radio sampling boxes) can be bought off-the-shelf. I have no idea if enough amateur astronomers would buy these for them to be marketable (they wouldn't be cheap - tens of thousands of dollars per kit).
Why was that guy modded down? He's right, and it is relevant to "mindpixel" and his interviews. Ask around in that guy's hometown...there's a reason he doesn't live there anymore, and it's probably closer to lynch mobs than you think. I went and looked at mindpixel's press web page - the lies are laughable when you know the real story.
Demonstrant's Open Source Tools
Don't you think it'd be a bad idea to place a multi-billion dollar satellite in an area of space where the sun "...focuses all electromagnetic radiation passing it to a resolution beyond anything possible with human engineering." ? In order to be useful (i.e. have an electromagnetic image in focus) the 'scope would have to be near the focal point where DC-gamma radiation levels would be unbelievably high.
Also, is a 76 hour one-way light travel time going to cause problems? We have enough angst waiting for stuff from mars.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
I am writing about this topic, and have corresponded with a number of NASA and Space Telescope Institute scientists about the idea of using the sun's gravity to magnify distant objects. The consensus is that while this is an interesting idea to play with, it won't be happening for generations, if ever.
To start, our most distant Pioneer probe won't be at 550 AU for 180 years. Pluto, remember, is just at 39 AU. Radically increase speed and you'll have a probe there in what, 80 years?
Once there, where will you point it? You'd have to spend hundreds or thousands or years arcing the telescope into different positions to see a broad sweep of space. And we don't have that kind of fuel technology, including nuclear.
I was in love with the 550 AU idea (I've read that 763 AU might be ideal), but the reality check dampened that more than a bit.
I hope this helps.
Erik Baard
The online conspiracy theory game, Majestic, already floated this idea. The following is a *fake* news article from the game. It is *not real.* My pen name for that game is Christian Larkin.
The home satellite dish idea is in the closing graph.
Earth Begins To Fade From Galactic View
By CHRISTIAN LARKIN (Special to SPACE.com)
Mountain View, CA, November 16, 2001. You can watch "Aliens" on DirecTV, but as a result fewer aliens will be watching you. At a time when the sphere of radiation carrying "I Love Lucy" has reached a radius of 50 light years, stray emissions from Earth into outer space are plummeting as communications technology moves away from the big broadcast antenna or yore into new delivery systems.
Like a ship deliberately eluding detection, we may slip into global radio silence.
In other words, for extraterrestrial civilizations scouting weak radio frequencies for signs of intelligent life in our neighborhood in future millennia may miss Earth because for practical purposes our beacon will have winked out.
Astronomer Frank Drake, SETI (Search for Extraterrestrial Intelligence) Institute chief and author of the famous "Drake Equation" for calculating the number of civilizations beyond Earth, expressed his dismay in the book "Here be Dragons," by David Koerner and Simon LeVay.
"The thing that's ringing alarm bells for me," says Drake, "is that we see our civilization going very rapidly toward the use of fiber-optic systems, and direct to home satellites. A typical TV station radiates a million watts, but a typical satellite transmits at 100 watts, and of that only about 10 watts leak out into space. So we're rapidly losing visibility--by a factor of 100,000. Is that typical or quirky? We don't know, but it's a warning signal."
But while Drake fears the Earth will become a wallflower at the galactic dance, other express relief.
"Earth is dimming, and that may just save our civilization," according to researcher who requested the he remain anonymous. "I am certain that extraterrestrials exist, though I can't tell you why. All I can say is that we're not ready for our coming out party."
The fear of premature detection is one UFO enthusiasts have debated for years.
Experts say that one solution for those want to be spotted is to actively send transmissions in strong and steady streams in the frequency that matches quantum transitions of hydrogen, the most common element in the universe. Radio astronomers use the hydrogen band as a benchmark, much as videotape cameramen "white balance" their instruments.
Ironically, the plethora of home satellite dishes currently forcing the demise of broadcast television and radio could also be a boon for SETI. Eventually, linking volunteers with such hardware in an effort to scan the skies could propel the hunt for alien messages more economically than building large telescopes like the Arecibo Observatory in Puerto Rico. The effort to process radio waves from outer space has already gotten a boost from volunteers donating time on home machines for a parallel computing program called SETI@home.
Copyright 2001 by Space.com, Inc
Must be sad to be incapable of anything more complicated than going bowling.
This is correct. Atmosperic distortion, turbulence mainly, has been the major problem for large telescopes on the ground. However using adaptive optics we can now compensate for much of this distortion. The basic idea is to use either a known reference star close to the observed object, or an artificical reference point created by shining a laser at a particular layer in the atmosphere, to find out what the "shape" of the distrotion is.
This is done continously and the information is fed into a computer which caluclates how to deform the mirror, or mirrors, in order to get an undistorted light beam to the detectors in the telescope.
Using this kind of technology the European VLT will be able to create better pictures from the ground than the Hubble do from space. The current belief is that the limit for adaptive otpics will be reach with telescopes of a radius of 130-150 meter.
However space based telescope are still the only way to observe at wavelengths which are aborbed by the earths atmosphere.
If gravitational bending of light is the principle being used, and we're using the Sun simply because of its greater gravity, you're right about the distance being impractical. How about this? Why not use the earth's gravity as our lens instead? The light curvature is proportional to the mass, and the Sun is 333,400 times more massive than the Earth, then shouldn't the distance needed be 550 x 93,000,000 x 333,400 = 153,000 miles? That would put it within the Moon's orbit, easily within the neighborhood for maintenance, and I think all we'd need to improve is the precision of the measuring instruments to compensate for less gravitational bending. Mind you, I haven't taken any optics courses, so I could just be completely wrong...
Ok, this is off-topic, but used to think that using 10 as the base for "orders of magnitude" was a bit big. For instance, if a is five times as big as b, then they really are totally different quantities. The b quantity is only a small fraction of a, and is relatively insignificant, so I think they deserve to be considered different orders of magnitude.
On the other hand, a factor of two seems not to be big enough. If a is twice as big as b, they seem still to be in the same ballpark. The b quantity is a significant portion of a, such that subtracting b would completely change the character of a.
So, I came to the conclusion that e, the base of the natural logarithm, should also be the base for "orders of magnitude". To me it seemed like about the right ratio to raise one number into a whole different category from another.
However, since most of us still count on our fingers, ten it is.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....