Become a fan of Slashdot on Facebook

 


Forgot your password?
Close
typodupeerror
×
Space Science Technology

Telescope Will Have Images 10X Sharper Than Hubble 315

Posted by timothy from the projections-of-grandeur dept.
jangobongo writes "After a 20 year struggle, the University of Arizona's $120 million Large Binocular Telescope was dedicated last week. This unique telescope will have twin 8.4-meter (27.6 foot) mirrors that sit on a single mount. Using methods similar to a medical CAT scan, a technique of "tomographic" image reconstruction will be used to produce pictures 10 times sharper (example) than the Hubble Space Telescope for a fraction of its $2 billion dollar cost."
This discussion has been archived. No new comments can be posted.

Telescope Will Have Images 10X Sharper Than Hubble More

Telescope Will Have Images 10X Sharper Than Hubble

Comments Filter:

  • Hubble Comparison? (Score:4, Insightful)

    by Locky ( 608008 ) on Sunday October 17, 2004 @07:51PM (#10553121) Homepage
    I don't really think it's fair to compare this with the hubble, unless this telescope can orbit earth.

    • Re:Hubble Comparison? (Score:5, Insightful)

      by drudd ( 43032 ) on Sunday October 17, 2004 @07:59PM (#10553175)
      Why not? The point of Hubble is to be diffraction limited rather than seeing limited (due to being above the atmosphere).

      Adaptive optics makes putting telescopes above the atmosphere unnecessary (or less necessary, AO is still in it's infancy).

      If you can build a superior instrument for the cost of a single Hubble reservicing mission, why is it unfair to compare the price/performance to Hubble? No it doesn't have the same "coolness" factor that Hubble has, but as an astronomer, I don't really care about that.

      Doug

      • Re:Hubble Comparison? (Score:5, Informative)

        by Graymalkin ( 13732 ) * on Sunday October 17, 2004 @08:17PM (#10553261)
        Adaptive optics is great but what about UV and IR spectrography and imaging? One of the HST's best features is the ability to image and get spectrums from UV all the way to IR. Ground based telescopes only get a fraction of the spectrographic information the HST receives. A great deal of the recent information regarding supernovae has come from UV images and spectra from the HST as have excellent H2 and dust maps of our own galaxy. For cosmological structure observations ground based telescopes with adaptive optics can be wonderful tools but at the same time there is a definite need for observatories outside of the atmosphere.

      • sooooo.... (Score:5, Funny)

        by Anubis350 ( 772791 ) on Sunday October 17, 2004 @09:01PM (#10553458)
        but as an astronomer,

        so, you took up space in college eh?

        /me ducks

      • Re:Hubble Comparison? (Score:4, Insightful)

        by Bootsy Collins ( 549938 ) on Sunday October 17, 2004 @09:34PM (#10553596)
        No it doesn't have the same "coolness" factor that Hubble has, but as an astronomer, I don't really care about that.

        How do you plan on doing high-quality UV and IR observations from ground-based telescopes?

      • Re:Hubble Comparison? (Score:5, Informative)

        by mbrother ( 739193 ) <mbrother.uwyo@edu> on Sunday October 17, 2004 @10:02PM (#10553703) Homepage
        As another astronomer, I'll chime in that it's still apples and oranges. We couldn't build the LBT 15-20 years ago, and Hubble would be cheaper and better if we built it now. The points about the UV coverage of Hubble are especially good ones -- LBT will never work in the UV, and some science requires the UV. Furthermore, the results from the LBT will not be simply "10x" better resolution -- there is atmospheric effects to worry about and compensate for, and there is only a single baseline (to get 360 degree interferometry will require quite extended observations to get what astronomers call "coverage in the u-v plane).

        Will the LBT kick astronomical ass? Almost certainly.

        Will Hubble still be able to do things LBT can't? Yes, indeed.

        Will the LBT be able to do things Hubble can't? Of course.

        The Hubble cost-analysis is way more complex than these simple comparisons on slashdot always seem to apply. At this point, the appropriate questions are things like, is Hubble worth the cost of maintaining? Does it still provide a unique capability? What is the value of that unique capability? When can a bigger, better replacement fly? Etc.
      • Its fair to compare price/performance ratio.
        However, exactly like the firsat posts I was imediatly pissed by the "tone" of the aricle, implying that Hubble was wasted. No, it is not literally written there. But ending a sentence (the whole article even) with "for a fraction of its costs" implies the author wants to play down Hubble.

        That said: AO was not available, no idea if it was even thought about it, when Hubble was planned and crafted (early 80s).
        Hubble anyway excells in the bearly invisible spectrums

    • Re:Hubble Comparison? (Score:5, Funny)

      by nwbvt ( 768631 ) on Sunday October 17, 2004 @08:06PM (#10553206)
      Are you for some reason under the impression that the sole purpose of the Hubble is to be a large object orbiting Earth?

    • Re:Hubble Comparison? (Score:4, Informative)

      by Anonymous Coward on Sunday October 17, 2004 @08:37PM (#10553356)
      Agreed, it's not a completely fair comparison. Adaptive optics and interferometry technology on ground-based telescopes will be great advances but they can only operate at near-infrared wavelengths and only create images over a very tiny field of view. Hubble has the advantages of being able to observe in the UV and visible and to have a completely stable image quality, which you would not get from the ground even with adaptive optics. There are still a great variety of scientific projects that can only currently be done with Hubble. It would be really inaccurate to claim that these kinds of ground-based imaging technologies can replace the diverse capabilities of Hubble.

      • Re:Hubble Comparison? (Score:4, Interesting)

        by mbrother ( 739193 ) <mbrother.uwyo@edu> on Sunday October 17, 2004 @10:17PM (#10553782) Homepage
        One point about AO that's rarely appreciated is that the point source function (PSF) changes. The spatial resolution doesn't just improve by "factor x." A lot of the light becomes spatially concentrated, but a lot of the light remains in the "wings" of the PSF. One application I'm fond of for high spatial resolution is imaging quasar host galaxies. In quasars, the host galaxy is usually lost in the glare of the central quasar. AO helps, but not so much -- the wings of the PSF still swamp out the faint surrounding galaxy. There are tricks to play, to push the technology to do this kind of science, but cutting edge work is usually complex.

    • Re:Hubble Comparison? (Score:3, Interesting)

      by Z3nN3rd ( 709214 )
      I live in Safford and you guys should see this thing! Its freakin' huge, you can see it from town and for miles around, this big ol' white box up on the hill. Its awesome! Its also a win for scientists vs. environmentalists. The wackos have opposed this for years and their efforts led to the unchecked fire that almost destroyed the site this summer.

      • Re:Hubble Comparison? (Score:4, Informative)

        by BlueStraggler ( 765543 ) on Monday October 18, 2004 @12:26AM (#10554242)
        Why on earth are environmentalists opposed to an observatory? I mean astronomers not only like clear air, they even think light is pollution!

        • Re:Hubble Comparison? (Score:3, Insightful)

          by TWX ( 665546 )
          "Why on earth are environmentalists opposed to an observatory? I mean astronomers not only like clear air, they even think light is pollution!"

          Because unfortunately there are those who are completely uncompromising, and in this case the fact that the telescope complex takes up a fairly large amount of space and would alter as-of-yet unaltered land was probably what set them off. Personally I find this to be stupid to the largest extent, as it is as short sighted as groups who would completely annhilate
          • "Because unfortunately there are those who are completely uncompromising, and in this case the fact that the telescope complex takes up a fairly large amount of space and would alter as-of-yet unaltered land was probably what set them off."
            OK, I agree with you that the telescopes on Graham should be built, but your characterization of the opposition is wrong. There were two main reasons why the telescopes were opposed: 1) Mt. Graham is the home of the endangered red squirrel. 2) Mt. Graham is the sacred

  • "Seeing Limited"? (Score:3, Interesting)

    by wildsurf ( 535389 ) on Sunday October 17, 2004 @07:52PM (#10553130) Homepage
    The "example" image shows the upper left corner as "Seeing Limited", but it's not clear what that means. Not the human eye, obviously? Anybody know?

    • Re:"Seeing Limited"? (Score:5, Informative)

      by Scott Ransom ( 6419 ) <sransom AT nrao DOT edu> on Sunday October 17, 2004 @08:01PM (#10553186)
      "Seeing" is the wobbling back and forth of portions of an image caused by the turbulence of the atmosphere. The many "seeing cells" above a telescope act as lots of little lenses and distort an image taken from the ground. In general, the best sites in the world can sometimes allow "seeing"-limited observing down to around 0.2-0.4" (that is the best resolution possible -- which is much less than would be possible with a large telescope in space). However, adaptive optics (or interferometry) can sometimes beat this atmospheric limitation.

      And yes, IAAA (I am an astronomer).

    • Re:"Seeing Limited"? (Score:5, Informative)

      by Anonymous Coward on Sunday October 17, 2004 @08:04PM (#10553198)
      Seeing limited means limited by the turbulence in the Earth's atmosphere. There are lots of cells of turbulent air in the upper atmosphere that make the stars twinkle -- this is the bane of ground based observing. The whole point of putting a telescope in space (at least in the optical bands) is to avoid this 'twinkling' effect. Astronomers call this seeing, and go to great lengths to try to build telescopes in places (like Hawaii, Chile, etc.) where the seeing is good. Good seeing usually means about 1 arcsecond -- this is much better than what you see when you go out in your backyard in most places. Pretty exceptional seeing is 0.5 arcseconds or better. HST, which is above the atmosphere, is not limited by seeing, but IS limited by the size of it's mirror. Because of the wave nature of light, every telescope has a limit on how sharply resolved it's images can be based on the diameter of the telescope. A ground based large telescope, like Keck or the LBT, would always have better image quality that Hubble IF you could get that pesky atmosphere out of the way.

      Now, in the past few years something called adaptive optics has become popular. It consists of techniques to correct for the twinkling and make the big, ground based telescopes, see more clearly (in some sense) than HST. The problem is that this only works in the infrared -- not in the optical bands. So we can now do better in some ways from the ground than in space, but not at all wavelengths.

      The claim that the LBT is x times better than Hubble is somewhat misleading. Again, this only applies to the infrared -- NOT the optical. And even in the infrared the story isn't really that simple -- with adaptive optics (at least) you tend to get a narrow core that is really, really well defined, much better than Hubble, but then there is a large skirt of less corrected light around the sharply defined core. So for some purposes adaptive optics isn't really better -- like if you need to measure all of the light. This is (naturally) being worked on.

      Another problem is that for most adaptive optics systems you need to have a pretty bright star right next to what you are looking at -- which isn't true for most parts of the sky. People are bulding laser systems that create artificial bright stars wherever they want to look, but they aren't as common, don't work as well, and are difficult to use -- among other things you have to file an observing plan with the FAA to make sure you don't accidentally shine the thing at a plane flying by.

      You shouldn't have this problem with the LBT, but I don't know about the previous one. And, as far as I can tell, it also only works in the infrared.

  • More info and not everybody like this... (Score:5, Informative)

    by erick99 ( 743982 ) <homerun@gmail.com> on Sunday October 17, 2004 @07:52PM (#10553132)
    At first I thought that this binocular telescope was going up in space to join Hubble. Just last week I had heard of another telescope that was going up and would actually trail behind earth a good distance in order to allow for cooler temperatures and less interference. This one, however, is planted in Mt. Graham in Arizona. One lens is complete and onsite and the second is supposed to arrive this coming spring.

    Here is a particularly good description of the LBT (Large Binocular Telescope) from an article in the Eastern Arizona Courier [eacourier.com].

    The LBT is made up of two 8.4-meter mirrors, which, when in place, will bring together the light, creating sharper images of faint objects in space. One mirror is in place at the Mount Graham International Observatory, and the other will arrive next spring. Each mirror is designed in a manner that allows it to reach the same temperature as the outside air up to two hours faster than any other mirror design. Under the solid glass surface are openings in a honeycomb pattern. Cold air is pushed up through those openings, cooling the glass to the desired temperature. The sooner the glass cools, the more science can get done, which is good from a business standpoint, assistant project director for LBT Jim Slagle said.

    Not everbody is happy about this, though. The Apache people are protesting the use of the site for the telescope.

    The U of A is finally dedicating it's Large Binocular Telescope (LBT), formerly called the Columbus Project, after years legal and money problems and at least a year before actual completion. (The U of A changed the name of the project after realizing it wasn't such a popular idea to name it the Columbus project and then, against the wills of the Apache people, place it on their most sacred site on top of the mountain.) The LBT is mainstay of the project. Investors will be wined and dined on Fri. at the La Paloma resort in the Catalina foothills and bused up to the mountain on Sat. to tour the scope site. Our job is to show the investors how controversial and unpopular this project is... and has been for decades.

  • As amazing as Hubble has been, I fail to see how dumping huge sums of money into keeping it going is worth it if we can dump similar sums of money into earth-based technology with better results.

    -S
    • No - there is lots that Hubble can do that this telescope can't, and lots that no earthbound telescope can do. (See my other comment on this article: #10553382 [slashdot.org]

      It is another question of whether that extra capability is worth the extra cost.

    • Re:Does this effectively obsolete Hubble? (Score:5, Informative)

      by Malor ( 3658 ) * on Sunday October 17, 2004 @09:02PM (#10553460) Journal
      Well, you have to realize, the Hubble is very, very old technology. It was actually completed in 1985, although it wasn't launched until 1990, because of the Challenger disaster.

      With that TWENTY YEAR OLD technology, we have gotten absolutely amazing results, as you have seen. After two decades of advancement, we can do even better from the ground, but that doesn't invalidate the science we have already done. (like that huge meteor strike on Jupiter; because of the Hubble, we practically had front-row seats). The money involved to keep Hubble running isn't that large, relatively speaking; the initial build and launch were very expensive, but we have already paid for those. Fixing the Hubble just needs to be cheaper than building a ground-based 'scope of similar quality, and I don't think there's any argument about that. And even if the Arizona telescope is better, that hardly makes the Hubble useless. There's never enough observation time for everyone on the really big instruments, and having several available would be good.

      The Hubble's successor should be as far past its ground-based competition as the Hubble was. Like it or not, that atmosphere is annoying: we can correct for its presence to some degree (which we couldn't twenty years ago), but it's even better to not have it in the way. We're trying to look unbelievably far away, and if we're not spending a great deal of time correcting for the atmosphere, we can spend time correcting for much smaller problems.... ultimately giving us far better pictures.

      Reemember the Hubble Deep Field -- in the darkest part of the sky, in an area about as large as a grain of sand held at arm's length, we saw at least 1,500 GALAXIES.

      There's a lot to see out there.
      • With that TWENTY YEAR OLD technology, we have gotten absolutely amazing results,

        Some of it has been upgrade by shuttle service missions.
      • "Fixing the Hubble just needs to be cheaper than building a ground-based 'scope of similar quality, and I don't think there's any argument about that."

        Estimates I have heard (and IANAA) have put the cost for further service missions at around have a billion dollars, which would be around 4 times the cost of building this telescope. And remember that mission will only keep the Hubble out for a limited time. Afterwards more missions will be required to keep it up longer. And money isn't the only problem.

        • Well, if that is indeed the case, then we should let the Hubble die. It's dumb to waste money doing something in orbit if we can truly do it better and cheaper from the ground. If we really do get more science spending the money on the ground, then spend it there... that's just sensible.

          I don't think the risk to the astronauts, however, is a particularly compelling argument. They know the risks in going up, maybe better than anyone. Perfect safety is appallingly expensive; if we can just do 'good safe

    • Re:Does this effectively obsolete Hubble? (Score:5, Interesting)

      by adminispheroid ( 554101 ) on Sunday October 17, 2004 @09:02PM (#10553462)
      No. There is an unfortunate tendency to compare every telescope to Hubble, whether the comparison makes sense or not. Hubble has two major specialties, UV astronomy and high resolution, and a minor specialty, near IR astronomy. LBT will not compete in the UV department -- it can't be done through the atmosphere. It is quite possible that LBT will do better than Hubble at high-resolution IR work -- but that isn't the main thing Hubble does.

      A requirement on all observing proposals to Hubble is that the observation can't be done by any ground based telescope. This is so we don't waste the expensive telescope time on something that can be done by the chearper telescopes. So when LBT starts operation, there may be some observations that would have been done on Hubble going to LBT instead. But certainly not all of them.

      In any case, the way things are going at NASA HQ, it'll be lucky if Hubble is still operating by the time LBT starts observing with both mirrors.

  • Terrestrial limitation (Score:5, Interesting)

    by Quixote ( 154172 ) on Sunday October 17, 2004 @07:57PM (#10553157) Homepage Journal
    I'm not an astronomer (IANAA), but doesn't the fact that a telescope is earth-based limit its field of view to (basically) a plane determined by the perpendicular from that point on the surface?

    A space-based telescope (like the Hubble) can be rotated and aimed at almost any object out there. In that sense, a Hubble is still superior in some aspects.

    On the other hand, just the fact that adaptive optics and interferometry can clean up the images so spectacularly is simply amazing!

    I wonder how long before I can get a consumer-grade version, to take pictures of the coeds^H^H^H^H <ahem> natural "scenery"... ;-)

    • Not at all. Observatories have huge rotating mounts to aim the telescope at almost any part of the sky. If the telescope couldn't be aimed, it would be impossible to take photographs because of motion blur caused by the earth's rotation.

      • Re:Terrestrial limitation (Score:4, Insightful)

        by WhiteBandit ( 185659 ) on Sunday October 17, 2004 @08:16PM (#10553258) Homepage
        I think the parent also means that we can't see things below a certain plane no matter what, mostly due to the fact that the telescope is stationarily located in the northern hemisphere. So this telescope can never be used to examine features in the southern sky.
      • You're still limited by the southern horizon (if you're in the northern hemisphere, of course.) If you're at, say, 40 degrees north latitude, you will never see anything within 40 degrees of the south celestial pole.


        The practical viewing area is even smaller, because objects near the horizon are obscured by atmospheric effects...so there's plenty of advantage to being in space.


        rj

    • Re:Terrestrial limitation (Score:5, Informative)

      by Michael Woodhams ( 112247 ) on Sunday October 17, 2004 @08:59PM (#10553448) Journal
      The horizon limits you to viewing half the sky. Atmospheric effects make it difficult/unviable to view close to the horizon, so in practice this is even more limited - say 1/3 of the sky. In addition, daylight restricts your observing time by a factor of more than two, and for faint diffuse objects (glaxies, nebulae) you also can't observe when a bright moon is in the sky, nor, of course, when it is cloudy - so maybe you end up with 4 hours per day of good observing time per night, on average. A space telescope suffers none of these limitations. (Well, just a little - you can't observe too close to the sun, moon or earth.)

      However, although you can only observe 1/3 of the sky at a given moment, the motion of the stars through the night and year means you can observe much more of the sky if you're prepared to wait. Furthermore, if the telescope costs a small fraction of the cost of a space telescope, you can build many of them in different parts of the world, to overcome these limitations.

      There are other reasons for going into space - atmospheric bluring, absorption and emission.

    • I don't know. (Score:4, Insightful)

      by pavon ( 30274 ) on Sunday October 17, 2004 @09:11PM (#10553500)
      The radius of the earth is about 6400 km, and hubble only orbits about about 570 km above that. If you do the trig, hubble only has a 225 deg feild of view at any one time compared to 180 on the earth (disregarding the atmosphere in both cases).

      Furthermore, both hubble and an earth bound telescop would have a somewhat limited view due to their "orbit". Concider a telescope on the equator. It would have a 180 degree field of view at any given time, and over the course of a day, everything would be in it's field of view except a cylinder the width of the earth, centering around the earths rotational axis, and extending to infinity in either direction. If you have telescope further north, it's daily field of view would have a cone shaped blind spot to the south. Hubbles orbital blind spot would be nearly non-existant over its orbit period, slightly better than the observatory at the equator, but that is easily solved by having two observatories - one in each hemisphere.

      Concidering how inexpensive these are to build relative to a space based telescope, there is no reason why we can't do this. In fact we have hundreds of observatories across the world, each new or improved one slightly better than the one befores, but only one space based telescope. Improvements in ground telescopes will also be available to many more researchers, than with just one expensive space telescope.

      • Re:I don't know. (Score:5, Insightful)

        by mbrother ( 739193 ) <mbrother.uwyo@edu> on Sunday October 17, 2004 @10:22PM (#10553809) Homepage
        This stuff is even more complicated that you think. Hubble schedulers (and I have an old office mate who is one of these people) have all sorts of restrictions to obey. They can't look too close to the Earth, or sun, and can't look with some instruments during some phases of the orbit (e.g., flying over the South Atlantic Anomoly or SAA). On the other hand, there exist "Continuous Viewing Zones" near the poles for which Hubble can pretty much look at constantly throughout it's entire orbit, so their especially efficient.

        Overall, Hubble is less restricted than any ground-based telescopes because it can look closer to the sun than any of them. We used to have all sorts of problems making quasi-simultaneous ground-based observations, because they would schedule Hubble observations a month later/earlier than we'd be able to see a target from our telescope in Texas. That atmospheric scattering hurts in more ways than one.

    • Re:Terrestrial limitation (Score:5, Insightful)

      by andrew cooke ( 6522 ) <andrew@acooke.org> on Sunday October 17, 2004 @09:20PM (#10553534) Homepage
      other people have commented that you get to see more than that due to rotation of the earth during the night, and movement of th eearth around the sun during the year.

      however, there's a more fundamental reason why this is largely unimportant - the universe doesn't have a special direction, it's pretty much the same everywhere. so while you might not be able to see a certain object from a certain telescope, you can see another one pretty much like it.

      there are exceptions, of course. if you're looking at objects in our galaxy then you may need to use a certain telescope, because the position of the galaxy relative to the earth is pretty much fixed. so for "nearby" objects it may be important. also, at the extreme opposite, observations of large scale fluctations in the very early universe (effectively observing *very* distance objects) may require all-sky observations.

      but for many interesting objects - other galaxies, quasars, radio galaxies, etc there's no real loss to being restricted to one particular direction.
    • Actually, as far as Field of Regard goes (Field of view is a measure of how much you can see looking through the sensor...) there is very little difference between a telescope in Low Earth Orbit (LEO) and one on the Earth's surface. In both cases, the Earth blocks out about 2/3 of the viewable universe. Being 600 km above the surface of an object that is 12600 km in diameter doesn't help too much. However, Hubble of course moves through its orbit many times over one Earth day, so what its FOR changes pre

  • Ugh. (Score:3, Interesting)

    by darkmeridian ( 119044 ) <<moc.liamg> <ta> <gnauhc.mailliw>> on Sunday October 17, 2004 @07:58PM (#10553166) Homepage
    But what about the frequencies sucked up by our atmosphere? These wavelengths are pretty cool to stare at, right?

  • Pardon me for asking... (Score:3, Interesting)

    by WIAKywbfatw ( 307557 ) on Sunday October 17, 2004 @07:58PM (#10553170) Journal
    Pardon me for asking, but isn't atmospheric interference still a factor for ground-based observatories? Won't this affect their observations?

    Granted, the telescope's location is a plus in this department (there are few locations more suitable) but the potential interference is still a consideration. I've read their page on ground versus space telescopes [arizona.edu] and it touches on this issue, talking about fast computers and adaptive optics that correct atmospheric blurring, but it's not an issue for which you can completely compensate.

    Having said that, a ground-based observatory is a heck of a lot cheaper than an orbital one...

  • Concerning Hubble (Score:2, Interesting)

    by Anonymous Coward
    Slightly OT and perhaps a stupid question, but I always asked myself if hubble was turned against earth, would that give you the possibility to get a very detailed image (assuming no clouds)? Anyone here who knows why or why not at all?
    • I'd suspect it would have something to do with it not being able to focus that close. Just like if you point a camera at something 5 cm in front of the lens, it wouldn't be able to focus on it, and you'd get a really fuzzy picture.

      • I'd suspect it would have something to do with it not being able to focus that close. Just like if you point a camera at something 5 cm in front of the lens, it wouldn't be able to focus on it, and you'd get a really fuzzy picture.

        So what you're saying is they forgot to implement a macro mode on Hubble. Silly astronomers--oh wait...

    • Re:Concerning Hubble (Score:2, Interesting)

      by Anonymous Coward
      try googling "KH-11"
    • the earth rotates too quickly to begin with, the hubble's minimum exposure time is 1/10th of a second, and hence the earth will have rotated a large distance in that time; in addition to hubble moving, since it orbits aproximately once every 100 minutes. also, it might be slightly too close to get good definition of its target

    • Re:Concerning Hubble (Score:4, Interesting)

      by argent ( 18001 ) <peter@NOsPAm.slashdot.2006.taronga.com> on Sunday October 17, 2004 @08:54PM (#10553433) Homepage Journal
      The instruments in the Hubble are likely to be damaged by the brightness of the Earth.

      But don't worry, the Keyhole scopes the US intelligence community use are basically Hubbles pointing at the earth, with appropriate instruments. Of course they don't let anyone see the pictures or admit they exist, but that's a minor detail.
  • ...on the Hubble. Aside from the many fun times we've all shared in its ups and (almost) downs, it was only a matter of time before a better technology would be available for less money.

  • they have 4 open positions (Score:3, Informative)

    by edalytical ( 671270 ) on Sunday October 17, 2004 @08:26PM (#10553303)
    Job opportunities at LBT. [arizona.edu]

    Sadly, I'm not qualified for any of them.

  • Could the data captured by this telescope and the HST be combined together to make a telescope with an even large "virtual" diameter?

  • slug bug! (Score:3, Funny)

    by brainspank ( 515274 ) on Sunday October 17, 2004 @08:32PM (#10553331)
    I spy, with my $120m eye...

    something black and vacuous!
  • How many good observation locations are left to build large telescopes of this magnitute. Most places that might seem obvious can't work due to any number of locations. Sooner than later, we're going to have problems finding an available peak to plant one of these.

    Just a thought

  • Hubble is not obsolete (Score:5, Informative)

    by Michael Woodhams ( 112247 ) on Sunday October 17, 2004 @08:43PM (#10553382) Journal
    The story gives the impression that the LBT will completely replace Hubble, and do a better job, while being vastly cheaper.

    This is an overstatement. There is lots that Hubble can do that no other telescope can, being a unique combination of aperature (light gathering power and resolution), instruments (many wavelengths, imaging and spectroscopic) and being above the atmosphere (no 'seeing', no atmospheric absorption or emission in UV and IR.)

    (This is not to downplay the LBT - doing better than HST in some aspects, and as well but much cheaper in others, is very valuable.)

    Having quickly scanned the website for this telescope, I can't see how they are counteracting the bluring of 'seeing' (atmospheric turbulance). It is inconceivable that they have neglected it, but I don't see where. Adaptive optics can help, but have limitations of their own.

    Another limitation of the LBT is that the high resolution reconstruction will require 3 observations at different times - so it only works well with non-time-varying targets. This is a minor limitation, however - a large majority of targets for which you want high resolution are non-variable.

    (IWAA: I was an astonomer. PhD, but no further.)
    • Yes, there are things that Hubble can do that no other satellites can do, but not for the reasons you listed.

      Hubble is one of multiple telescopes in NASA's Great Observatories [nasa.gov] project.

      There are currently three space-bound observatories for astronomy.
      For instance, Spitzer [caltech.edu] meets the qualifications you gave, the difference being that it operates in the IR range [nasa.gov], while Chandra [nasa.gov] looks at x-rays.

      Hubble [stsci.edu] works in the visible range. But that's not to say that it's the only space-based visible spectrum satellite,

  • Seeing Planets (Score:5, Informative)

    by adam31 ( 817930 ) <adam31 @ g m a i l .com> on Sunday October 17, 2004 @08:51PM (#10553423)
    Since I think that seeing planets outside our solar system is cool, my first question when RTFAing was "Will we be able to see planets outside our solar system?" The answer took a little while to find, so for anyone interested:

    It will permit formation of images of sufficient sharpness (diffraction-limited) that the planet could be detected against only a low surface brightness halo of residual scattered light. In this manner, a Jupiter-like planet could be detected, if present, around some fifty of the nearest stars. The interferometric mode will enhance the planet/background contrast even further, thus increasing the number of candidate stars and the sensitivity of the survey. The direct detection of such a planet would surely be counted as one of the major steps forward in determining the likelihood of life existing elsewhere in the Universe and in understanding our place in it.

    So, gas giants, but no mention of anything Earth-like. Too bad. I'd definitely be psyched to someday hear about "Earth-sized planet discovered about an AU away from a Sun-sized star."

    • Re:Seeing Planets (Score:4, Informative)

      by Howzer ( 580315 ) * <{grabshot} {at} {hotmail.com}> on Sunday October 17, 2004 @10:01PM (#10553702) Homepage Journal
      When I first heard about this telescope on the grapevine, I jumped onto the web and found the email of the project lead (people were rather careless about putting live emails on webpages in those days) and emailed about this very topic.

      My questions was "Will this be able to resolve earth-like planets around nearby stars?" To which the answer was "No. Need 2 orders of magnitude better resolution."

      In fact, in some rather extended searching, it appears there isn't even anything on the drawing board which would be able to achieve this feat. That's not to say that this is important, or anything, just cool! Who wouldn't take a second look at the first pictures of another "earth" around another star in their morning newspaper?

  • I keep hearing that (Score:5, Informative)

    by Tablizer ( 95088 ) on Sunday October 17, 2004 @09:20PM (#10553538) Journal
    I have seen several stories of telescopes that promise equal-or-better than hubble images. Usually there are some drawbacks. Here are some of the drawbacks that came up:

    1. Limited range of sky

    2. Frequencies different than hubble, such as only infrared.

    3. Only works near bright stars due to "guide-star" anti-blur technology.

    Let's see if new techniques get around these.

  • Why don't they build one of these on the moon? (Score:3, Interesting)

    by mark-t ( 151149 ) <markt AT nerdflat DOT com> on Sunday October 17, 2004 @09:43PM (#10553628) Journal
    Seriously... they get all the advantages of an orbital telescope like the hubble plus all the stability of a terrestrial platform. The moon may be somewhat more difficult to get to than orbit for repairs to something like the space telescope but it's still far from infeasable, and almost certain to be worthwhile in what we could discover.

    Heck. we could even build a whole telescope _array_ on the moon... just imagine what we would be able to do with that!

    • Re:Why don't they build one of these on the moon? (Score:3, Interesting)

      by Anonymous Coward
      The basic limitation to the size of a telescope you can take off the Earth's surface is the diameter of the launch vehicle, not platform stability. For reference, Hubble's primary mirror is 2.4m diameter, and the shuttle's bay (largest payload capacity available, I believe?) is 4.5m across.

      Future space telescope concepts include deployable mirrors and such.

      The moon's only advantage would be if you had a mirror manufacturing facility there, which clearly isn't going to happen anytime soon. ;)

    • Re:Why don't they build one of these on the moon? (Score:5, Informative)

      by Idarubicin ( 579475 ) on Sunday October 17, 2004 @11:26PM (#10554055) Journal
      Seriously... they get all the advantages of an orbital telescope like the hubble plus all the stability of a terrestrial platform.

      Well, almost all. There are a couple of difficulties with respect to pointing. Even under a sixth of normal gravity, you still need a much beefier structure to rigidly support a telescope on the Moon, compared to the same object in space. Particularly when the direction of that gravitational force changes as you tilt the telescope to follow objects.

      In principle, you could build a space telescope of hundreds of meters in diameter, and it wouldn't sag. You'd have to brace it a bit for aiming motions, but you can do those at a hundredth of a gee, not a sixth--and the stress is off again once you're aimed.

      For a really big telescope, that's another advantage of being in space--you don't have to move it while imaging. Point it, and it keeps looking at the same object for as long as you want to integrate. On the Moon, you have to track objects across the sky.

      The ESA's Darwin [rl.ac.uk] project proposes a free-flying array of six(!) 1.5 meter telescopes up to five hundred meters apart, with their relative positions controlled to within micrometers to do optical interferometry. They want to be able to do things like 40 day exposures to measure the spectra of extrasolar planets and possibly detect life. I don't mean to suggest that such a facility isn't possible on the Moon, but assembling and reconfiguring it (if necessary) is probably a lot easier in space where you don't have to pour concrete foundations.

    • The moon's not that great a place for a telescope (Score:4, Interesting)

      by bitingduck ( 810730 ) on Monday October 18, 2004 @02:22AM (#10554539) Homepage
      The moon isn't that great a place to build a telescope -- it isn't as stable a platform as being in space-- things hit it and shake it, and there's dust falling all over. You also have the problem of having to land everything gently as it drops into the moon's gravity well, which ends up costing you more energy. You're also in a varying thermal and solar environment, which is hard on equipment and decreases throughput.

      Heliocentric orbits (e.g. earth trailing) or the Lagrange points (cue ZZ top) are nicer, more stable environments to put your space telescope into.
    • There's an article Buyer s guide to telescopes at the best sites [arizona.edu] which considers deep space lunar and Antartica locations in detail. All have pros and cons.

  • This is not a replacement for Hubble (Score:3, Insightful)

    by francium de neobie ( 590783 ) on Sunday October 17, 2004 @09:51PM (#10553649)
    While this telescope may have even better resolution power than Hubble, there's another major problem with all ground-based telescopes

    They cannot detect EM waves that's not either visible light or in the radio wave to the far infrared range

    This is because Earth's atmosphere, contrary to what most people would believe, is not transparent to EM waves of all wavelengths. For example, common sense tells us that it blocks almost all extreme UV light. So if you want to observe an object that emits only extreme UV light with a ground-based telescope, you're not gonna see it.

    Another example would be gamma ray bursters. Remember these objects weren't detected until the US sent survillence satellites into space? This is because there's no way you can detect gamma rays that originated from space inside the atmosphere. Granted it's now possible to observe the after-glow of GRBs with ground-based telescopes, GRBs must still be detected from space telescopes beforehand.

  • Won't work (Score:5, Funny)

    by Robber Baron ( 112304 ) on Sunday October 17, 2004 @10:18PM (#10553791) Homepage
    The two 8.4 meter (331 inch) diameter primary mirrors are mounted with a 14.4-meter center-center separation.

    Nobody's eyes are that far apart.

  • Keck? (Score:3, Insightful)

    by kf6auf ( 719514 ) on Sunday October 17, 2004 @10:25PM (#10553818)

    I am only an ameteur astronomer but wouldn't a more valid comparison be to (the slightly lesser known) Keck Telescopes on Mauna Kea? For those of you who are not familiar there are twin 10-meter telescopes on Mauna Kea, which I'd be willing to be has infinitely better seeing (read: atmospheric conditions; the light is distorted less) than New Mexico.

    In addition, one can add instrumentation and the like to ground based telescopes and not really to space based onces - hence, Keck would be a much better comparison.

    Finally, I don't understand why such a big deal is made of the implied revolutionary methods that are used to combine the images from each scope. If anyone knows, is this different from any other dual telescope setup?

  • tomographic image reconstruction... (Score:3, Interesting)

    by sonamchauhan ( 587356 ) <sonamc@NOsPam.gmail.com> on Monday October 18, 2004 @08:23AM (#10555553) Journal
    From the article:

    the LBT places fringes on each point-like portion of the image. When we combine pictures taken with these fringes at three different angles, the fringes cross and give information about the exact placement of the point of light, distinguishing other points of light close to it. It is the crossings of these fringes that allow us to reconstruct a high resolution image.

    So, does this mean that video from 2 cheap webcams pointed at the same subject, can be combined to a single higher quality stream?

    The Intel Intel Open Computer Vison library [sourceforge.net] already uses binocular vison to track objects in 3D space. Can it be applied to this application?

Slashdot Top Deals

No spitting on the Bus! Thank you, The Mgt.

Close