Timescapes - Digital Timelapse Discussion

Giant Magellan Telescope to View Extrasolar Planets?
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Author:  timescapes [ Sat Dec 27, 2008 10:19 am ]
Post subject:  Giant Magellan Telescope to View Extrasolar Planets?


ASK ASTRONOMERS WHERE the next frontier in space research will be and the answer is unanimous: a giant telescope due to be built on a remote mountain top in Chile.

With up to 30 times the resolving power of current telescopes, the Giant Magellan Telescope promises to answer some of astronomy's most fascinating questions.

The history of astronomy is marked by technological leaps that led to new discoveries. Galileo revolutionised astronomy with his 37-millimetre telescope, as did Edwin Hubble with his two-metre optical telescope, and his namesake, the Hubble Space Telescope, with its 4.2-metre telescope and view from space.

New telescopes are being built all the time. So why build another, and what's causing the buzz?

A world consortium of astronomy organisations plans to build the Giant Magellan Telescope (GMT) on a mountaintop near the village of Residencia in Chile's Atacama Desert. It will cost US$600 million and should be ready by 2016.

With a resolving power ten times sharper than Hubble and five times sharper than its replacement, the James Webb Space Telescope, the GMT is a big step up in terms of power. Composed of an array of seven mirrors, each 8.4 m in diameter (some of the largest ground-based telescopes currently have a diameter of 10 m), it will have the capacity of a telescope with a diameter of 24.5 m – far larger than any telescope built so far.


SO GOOD WILL its resolving power be, that the GMT will for the first time look directly at the light from planets around other stars – which can be one billion times fainter than their parent stars. We currently know of more than 300 extrasolar planets, detected using various techniques.

In November, the GMT's older brother and sister, the twin 6.5-metre Magellan telescopes, zoomed in on the thermal emissions from one such planet. Hubble has detected methane, water vapour and carbon dioxide from the atmosphere of another large, hot planet – a so-called hot Jupiter, the easiest class of extrasolar planet to detect.

"Our hope is that GMT can detect planets using direct imaging and radial
velocity techniques and improve our understanding of systems already
known," says astrophysicist Scott Kenyon from the Harvard-Smithsonian Centre for Astrophysics in Cambridge, Massachusetts. "As an example, suppose we know a system with a hot Jupiter.

A GMT deep image would allow us to detect cold Jupiters farther from the star. Or if we image a candidate molten Earth, we can look for radial velocity variations to estimate its mass. And if the planet is bright enough, get spectra to learn something about its atmosphere."

http://www.cosmosmagazine.com/features/ ... -telescope

Looks like one serious telescope. :shock: :) Imagine what a breakthrough it will be if this telescope actually spots a planet directly, for everyone on this world to see?

BTW, how awesome would it be to shoot a timelapse of this baby in action. We only have to wait about a decade until it's ready. ;)

Author:  153957 [ Sat Dec 27, 2008 11:08 am ]
Post subject:  Re: Giant Magellan Telescope to View Extrasolar Planets?

Imagine what a breakthrough it will be if this telescope actually spots a planet directly

hehe, I hope you meant 'exo-planet'...

Yea, its a nice time to be in astronomy..
lots of new tech being made, new telescopes being built..
There's the European Extremely Large Telescope (a bit bigger then GMT) coming,
to be built around the same time.

Author:  timescapes [ Sat Dec 27, 2008 12:31 pm ]
Post subject:  Re: Giant Magellan Telescope to View Extrasolar Planets?

From the E-ELT Wiki page...

The European Extremely Large Telescope (E-ELT) is an extremely large telescope design proposed for the next-generation European Southern Observatory optical telescope with a mirror diameter of 42 metres (140 ft). ESO is focusing on this design after a feasibility study concluded that the proposed 100 metres (330 ft) diameter Overwhelmingly Large Telescope would cost $1.5 billion (£1 billion), and be too complex.

And then from the (postponed) Overwhelmingly Large Telescope's Wiki....

The Overwhelmingly Large Telescope (OWL) is a conceptual design by the European Southern Observatory (ESO) organization for an extremely large telescope, which was intended to have a single aperture of 100 meters in diameter, but was later scaled down to a 60 meter diameter telescope. Because of the complexity and cost of building a telescope of this unprecedented size, ESO has elected to focus on the less ambitious 42 meter diameter European Extremely Large Telescope instead.
While the original 100-m design would not exceed the angular resolving power of interferometric telescopes, it would have exceptional light-gathering and imaging capacity which would greatly increase the depth to which humankind could explore the universe. The OWL could be expected to regularly see astronomical objects with an apparent magnitude of 38; or 1500 times fainter than the faintest object which has been detected by the Hubble Space Telescope.

If built, it would be the largest optical telescope ever constructed. It has been claimed that OWL would have a greater mirror surface area than that of all previous professional telescopes combined.

If they were going to go to all that trouble, why not fabricate it on the moon and really get a nice view? :)

Author:  153957 [ Sat Dec 27, 2008 1:52 pm ]
Post subject:  Re: Giant Magellan Telescope to View Extrasolar Planets?

Because a space telescope would cost OVERWHELMINGLY more then a ground (Earth that is) based one.
The moon has a tiny (negligible) atmosphere, so much more problems with tiny meteors hitting the surface.
Temperature differences of about 250° Centigrate (-150° to 100°) would cause some problems with keeping the optics aligned properly.
Repairs would be harder..
And a telescope bound to a planet or moon's surface is harder to direct in a specific direction unlike a space mission.

ahw well.. we'll get there someday..

Author:  rlavoie [ Sat Dec 27, 2008 2:28 pm ]
Post subject:  Re: Giant Magellan Telescope to View Extrasolar Planets?

At the other end of the spectrum of telescope aperture, what about a 6 inch space telescope? It already exists, and performs very useful observations:

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