Posted on 12/30/2003 12:22:54 PM PST by Archangelsk
December 30, 2003 Astronomy's New Grail: The $1 Billion Telescope By DENNIS OVERBYEn the quest for some understanding of our twinkling existence, astronomers have built ever larger telescopes capable of catching and pooling the rare light of remote stars and galaxies.
Over the decades the torch of awe has been passed from mountaintop to mountaintop, from Mount Wilson, from where the expansion of the universe was discovered, to Palomar, home of the famous 200-inch reflector, which reigned supreme for almost half a century, to the cinder cones of Mauna Kea in Hawaii, where the twin 400-inch-diameter Keck Telescopes lord it over 13 others.
And even to space, where the Hubble Space Telescope is a peerless time machine.
Now the torch may be passed again.
Emboldened by the advances of the last two decades, groups of universities, observatories, nations and other research organizations are pondering plans for radical new telescopes that will dwarf even the giants on Mauna Kea and reach even farther into space and further back in time.
The proposals sport Brobdingnagian names like the California Extremely Large Telescope, or CELT; Giant Magellan; or the Overwhelming Large Telescope, OWL, a 100-meter-diameter behemoth being contemplated by a collaboration of European nations. And their proponents promise appropriately outsized scientific results.
The new telescopes, they say, will be able to deliver images sharper than the Hubble's, while gathering much more light, bringing into focus the blobs of primeval stars and gas from which galaxies were assembling themselves 10 billion years ago, or glimpses of planets around distant stars.
"With such a telescope you can for the first time really trace the connections between the first seconds of the Big Bang and the formation of life in the universe," said Dr. Rolf-Peter Kudritzki, director of the Institute for Astronomy at the University of Hawaii.
Astronomers say such a telescope will be needed to follow up and investigate the discoveries of the James Webb Space Telescope, scheduled for a 2011 launching, and the Atacama Large Millimeter Array, a radio telescope being built by the United States and Europe in Chile. In a report published in 2000, a committee of the National Academy of Sciences ranked a 30-meter telescope first on a wish list of new instruments for the coming decade.
But such a telescope also comes with a Brobdingnagian price tag — roughly a billion dollars to build, equip and operate for 20 years. That is more than the most recent generation of large telescopes cost altogether, according to a survey in Physics Today.
"We are really going to have a hard time building even one of these," said Dr. Richard Ellis, an astronomer at the California Institute of Technology, and one of the leaders of the effort to build the California telescope. Paying for such a telescope will require a merger of private and public sources of financing that is rare in astronomy, he said. Many large ground-based innovative telescopes in the United States, like Palomar and the Kecks have been built by private observatories and universities — not the taxpayer.
Dr. Ellis and his colleagues at Caltech and the University of California working on the California telescope have taken the first steps into this new era. This year the Associated Universities for Research in Astronomy, or AURA, agreed to join the California effort, which was renamed the 30-Meter Telescope. Subsequently the Gordon and Betty Moore Foundation granted Caltech and California $17.5 million each to help pay the cost of designing the telescope. AURA, which has no money of its own, has applied to the National Science Foundation for its share of the design cost.
But the 30-Meter Telescope has competitors, in particular the Giant Magellan, an effort led by the Carnegie Observatories in Pasadena, Calif., to build a 20-meter telescope in Chile.
AURA is a consortium of 36 educational and other institutions, which operates a network of national observatories for American astronomers. In an interview, the consortium president, Dr. William Smith, said it was important to move ahead in order to have a telescope by the time the Webb telescope was launched.
But the consortium's move to join the California effort dismayed some of its members, some of them involved in rival projects. They say that it is too soon to know yet what is involved in building a giant telescope or what is at stake scientifically in choosing one design over another.
In a letter to the National Science Foundation, 18 astronomers said in November that the agreement between AURA and CELT "may violate the principle of open competition." They included Dr. Peter Strittmatter, director of the University of Arizona's Steward Observatory; Dr. Irwin Shapiro, director of the Harvard-Smithsonian Center for Astrophysics; and Dr. Wendy Freedman, director of the Carnegie Obseratories. They urged the science foundation to hold an open competition to develop the best strategy for a giant telescope.
Dr. Michael Turner, the foundation's assistant director for mathematics and physical sciences, said all options were still open.
In statements and at meetings recently, he and Dr. Wayne Van Citters, director of astronomical sciences at the science foundation, have been circumspect, emphasizing the need for strategic planning before locking in a specific design. "The science that a Really Big Telescope can do has everyone excited," Dr. Turner said in an e-mail message. "We just have to figure out the best way to get there."
The road once ended at Palomar.
Palomar's Hale reflector, finished in 1948, was long considered the limit for ground-based telescopes. Bigger mirrors would just be too heavy.
But in the 1990's, technological advances made it possible to build thin, lightweight mirrors as large as 8 meters (about 26 feet) in diameter that relied on computer adjusted supports to keep the mirrors from sagging under their own weight.
The largest of the new breed were the Kecks, built by Caltech and California on Mauna Kea. Instead of being monolithic slabs of glass, their 10-meter-diameter mirrors are composed of 36 small hexagons warped and fitted together. The design was the brainchild of Dr. Jerry Nelson, a former particle physicist at the University of California at Santa Cruz.
The first Keck went into operation in 1993. By the end of the decade Dr. Ellis and his colleagues had already begun to study how to scale up the Keck idea. Last year they published a 300-page "conceptual design" for a 30-meter telescope with a mirror made of some thousand hexagons.
The new Moore Foundation grant, he said, will enable the California group to refine their design and study the trade-offs between size, cost and performance of a telescope.
In the meantime, they have also begun testing sites for the telescope in Chile; Baja, Mexico; and Mauna Kea in Hawaii.
Only when the design is finished, will the 30-Meter partners, which Dr. Ellis hopes will soon include the Association of Canadian Universities for Research in Astronomy, or Acura, be able to decide whether to proceed with building the telescope and with raising the serious money it will require.
With no "hiccups," Dr. Ellis said, the telescope could be ready in 2012.
While the California telescope will consist of many small pieces, the 20-meter Giant Magellan is to have only a few very large ones. Its main mirror will have only six circular segments surrounding a central one.
The project grew out of the twin 6.5-meter Magellan telescopes that have recently been built at Carnegie's Las Campanas Observatory in Chile by a partnership that includes the Universities of Michigan and Arizona, the Harvard-Smithsonian Center for Astrophysics, and the Massachusetts Institute of Technology, as well as Carnegie.
The plan capitalizes on the expertise of Dr. Roger Angel and his colleagues at the Optical Sciences Center at the University of Arizona, who have mastered the art of casting giant mirror blanks in a rotating furnace and then polishing them into shape. Each of the seven mirror segments is to be 8.4 meters in diameter, which is the biggest size his furnace can handle.
The telescope could be ready by 2015, if all goes well, the Magellan partners say.
Dr. Freedman, Carnegie's director, said she was optimistic that there would be resources and room on the planet for both the 30-Meter and the Giant Magellan, and that they could complement each other.
"We're all moving forward," she said after a recent meeting on telescopes at the National Academy of Sciences in Irvine, Calif. "We will succeed because the science is exciting."
Looming over these and other efforts is the prospect of a European giant.
That is the 100-meter Overwhelmingly Large Telescope contemplated by the European Southern Observatory, a multinational consortium that operates the world's largest array, the Very Large Telescope, on Cerro Paranal in Chile.
Dr. Robert Gilmozzi, an astronomer at the European Southern Observatory, said 100 meters was the minimum size needed to peruse Earth-like planets around nearby stars for signs of life.
The mirror for the proposed telescope has a novel spherical design that will allow it to be enlarged, or built in stages, said Dr. Guy Monnet, an astronomer at the European Southern Observatory and the project manager for OWL.
This means, Dr. Monnet said, that every segment of the primary mirror will be identical, simplifying the construction. It also means that the the European Southern astronomers can build a 60-meter telescope and see if it works, and then expand the mirror by filling out the sphere with more segments to make a 100-meter telescope. Such a telescope will be more likely if Americans participate, he added.
In order to realize their full potential the new telescopes will have to make maximum use of a new technology that undoes the blurring effects of the atmosphere.
In principle the resolving power of a telescope depends on its diameter — a bigger one can see finer detail — but in practice atmospheric turbulence, the same effect that makes stars appear to twinkle, blurs the stars and erases fine detail. This is why the Hubble, even though it is not large, only about 2.4 meters (96 inches), compared with the new giants on the ground, can do breathtaking work.
Lately astronomers have begun to learn how to tune out some of the blurring by monitoring the image of a bright star near the target of observation and continually adjusting a mirror inside the telescope. But these so-called "adaptive optics" systems have been added after the fact to existing telescopes.
The new big telescopes will be the first telescopes to have adaptive optics built in from the start, Dr. Ellis said.
What can you see with such a telescope?
Extraterrestrial planets are on the top of many astronomers' lists.
In the last decade more than 100 planets have been detected around nearby stars by their gravitational effects. These have all been very massive objects, at least as big as Jupiter, but the discoveries have fueled hopes that full-fledged systems with planets more like Earth, possible abodes of life, may eventually be found.
A giant mirror that could focus starlight into the smallest tiny point would be particularly well-suited to detecting planets. Masking out the bright star might bring the much fainter light of a planet otherwise lost in the glare.
Most of these would be the Jupiter-size planets, but Dr. Angel said 20- or 30-meter telescopes could be on the threshold of being able to detect Earth-like planets. A 100-meter telescope, with another tenfold increase in light-gathering power and even sharper images, he said, would be "extremely powerful." It would allow spectroscopy of Earth-like planets, he said, allowing astronomers to examine its atmosphere and perhaps rudimentary signs of life.
At the other end of creation, a really big telescope will be able to study what happened about 11 billion or 12 billion years ago when the universe was undergoing a rush of construction. Clouds of gas and dust collapsed and lit up as stars, which in turn began to transform the universe from primordial hydrogen and helium into the rich mix of elements like carbon and oxygen that have seeded life and wonder today. Meanwhile, clusters of stars were condensing into the first gawky-looking galaxies, ancestors of the milky spirals and bulging smooth clouds that now rule space.
But, Dr. Patrick McCarthy of Carnegie explained, "a large telescope will be able to see all the bits and pieces that coalesce into galaxies. That's where the physics is."
Don't know about non-US availability.
I got the 130mm reflector just about a year ago.
You looked at Saturn with it? Like, lately? Would appreciate some feedback if you have.
If you take a look at it any time soon, let me know how it went.
yes, but unfortunately, most of them refer to a type of "marital aid"...
Even better!
This is my first reflector/first equatorial mount, so there is a learning curve, not only in finding objects, but finding
them AND being comfortable while viewing.
Throw in the higher magnifications, Earth's rotation, etc, and it can be frustrating.
I went cheap. The GOTO scopes are worth considering for getting a lot of objects in a short amount of time.
I don't think I was successful with Saturn because of TOD/or weather, but Jupiter is a snap. I generally see the milky
view, with some of the moons as points.
Take a gander at http://home.inreach.com/starlord/
It's a Telescope Buyers FAQ for a starting point.
Aye, I imagine an equatorial mount is a bit difficult to get used to at first.
I've had a few looks at Saturn this past week with my binos. It's frustrating. You can sense that if you could just had a little bit more oomph you could see its rings. When I settle down in this world, I'm going to buy me a nice one- a Ferrari of scopes- might even build myself a nice little dome shaped observatory to keep it in ;-)
Well, I at least already think that we should blow'em up...no, no, must resist...must not stoop...to DU's level...
Greens used to be jus against technology - the applications of science. More recently, they have come out against scientific research itself. Witness the opposition to launching the long-range space probes, opposition to genetic research, and opposition to AI research and nanotechnology.
Not only is Mt. Graham not in Minnesota (it's in Arizona, where the clear skies are), but it isn't even on a reservation. The "sacred to the Indians" idea popped up out of nowhere several years ago after a period of Green opposition to University of Arizona and the Vatican building observatories on it.
The Greens' previous excuse had been that endangered squirrels lived on the mountain. After it was found that pine squirrels were not actually endangered, but were flourishing on Mt. Graham, as squirrels always do around humans, the opposition dreamed up the "sacred mountain" argument. Funny - no Apache had ever paid particular attention to the mountain before that; not when the summer camp was built on it, not when the cabins were built on it, not when the state campground was built on it, and not when Swift Trail Federal Prison was built on it.
Now Kitt Peak, the telescope-studded mountain on the other side of Tucson, is on a reservation. But in actual fact, the only tribe that considers telescopes to defile a mountain is the Green tribe. Fortunately, this being Arizona, we can shoot back.
Oh, there's been no shortage of thinking up. It's the building bit that has tended to go all wobbly. Remember Sanger? (to name just one of a pantheon of coulda-shouldas)
d.o.l.
Criminal Number 18F
Yep. Most politicians are verbal and to some degree anti-intellectual and distrustful of scientists. Scientists' habit of enumerating all the uncertainties and qualifiers on a statement is infuriating to politicians; unlike pols, scientists care about being wrong (or maybe more, about being reckless).
The general sense of most pols is that for each and every scientis you can find an equal and opposite scientist... this comes from most of them being familiar with lawyers and the junk science pimps that the plaintiff's bar finds in the messy corners of academia.
Give them consensus and they will give you money. The initial US space program got funded partly because Sputnik rattled everybody's cage except Ike's; but you can't overestimate how important leadership was, particularly Dornberger's. He kept all the staff, including Von Braun, on the reservation as far as predictions and promises to the political guys is concerned.
This suggests that absent a Dornberger in the current space program, neither our manned nor unmanned projects will get the priority they deserve.
d.o.l.
Criminal Number 18F
Well I have to take exception here. Most other ESA programs are a "me too" endeavors, IMHO. They tend to show little originality, inspiration or even scientific curiosity - they seem to owe their existence to some juvenile need to try to show the world that the Europeans are still in the game, and they come off poorly for this motivation. I think Herschel-Planck shows some real originality. has actual scientific benefit and may be - wonders of wonders - motivated mostly by scientific curiosity. It is also mostly a European undertakeing. I bleieve that we are only contributing about 10% of the work
That being said, it still is woefully inadequate and will be upstaged by the Webb telescope. It is too little late. This new American telescope will be the same sort of marvel as the Hubble was. To be fair, several European nations are contributing to the JWST, but its inspiration is purely American.
As for "building up." I have to agree with you there.
(What does "d.o.1" mean?)
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