7 mirror monster telescope proposed

[Dr Mordrid]

Should be able to gather 70 times more light and produce images 10 times sharper than Hubble

http://www.space.com/scienceastronomy/largest_telescope_040805.html

Texas A&M, U. of Texas/Austin, the Carnegie Institution, Harvard, the Smithsonian, MIT, U. of Arizona and the University of Michigan are involved and plan to place the instrument atop the Andes in Chile by 2015.

BTW: Hubbles spectrograph failed a few days ago, starting a debate over if a Shuttle mission will be slated for repairs now that those needed include things a robotic mission cannot do. The previous problems could have been handled robotically, but not now.

Many argue, and the NASA adminstration is among them, that the Hubble has outlived its usefullness and isn't worth the risk of a manned mission to fixc it.

Their position is basically that the money could be better spent elsewhere now that several ground based interferometers will far exceed its imaging power.

Another reason is that the next-gen space telescope due to be launched in a few years will concentrate on the infrared spectrum, which is where most of the new interest is. This would allow imaging furtrher back in the history of the universe because light from then is now red-shifted into the infrared. Hubble cannot do this kind of imaging.

Dr. Mordrid

[Brian R.]

Sharp images through the atmosphere? I hope they know what they are doing. I thought you were talking about an orbiting telescope.

[Dr Mordrid]

Nope. By using adapive optics (mirrors change shape in realtime to adapt to changing atmospherics) and linking several 'scopes together as an interferometer, you can now get sharp images from the ground.

Interferometry was invented by Albert Michelson and Dr. Edward W. Morley over 100 years ago. In the telesope context it makes use of separate mirrors or telescopes that are widely spaced by combining their images. While the interferometer does not capture as much light as a single mirror of the same diameter it can achieve almost the same resolution as the larger instrument.

Many, if not most, of the new and future ground based instruments are using this tech. and they all have mirrors MUCH larger than Hubbles.

An adaptive optics primer is here: http://www.mtwilson.edu/ao/

Dr. Mordrid

[Jon P. Inghram]

The big problem with ground based 'scopes is that the atmosphere is pretty much opaque at a whole lot of useful frequencies.

[Marshmallowman]

The adaptive optics is good tech (probably helped on its way becasue of the they had to fix hubbles original warped mirror)

But as Jon says, ground based telescopes still have some shortcomings, so hubble is still useful for the holes ground based stuff has.

[Dr Mordrid]

Infrared is the big problem (due to both red-shifting and absorption) when it comes to extreme deep-sky observations from the ground. This is why the James Webb Space Telescope (aka: next-gen space telescope) is set up for infrared;

http://ngst.gsfc.nasa.gov/FastFacts.htm

The JWST is an an 18-segment 6.5-meter (~20 ft. ) IR telescope that will be placed in an L2 orbit;

http://ngst.gsfc.nasa.gov/project/text/orbits.html

X-ray imaging, which is the other major band absorbed by the atmosphere, has been and will in the future be covered by space-based instruments.

HORUS (High ORbit Ultraviolet-visible Satellite) is a likely candidate for space-based ultraviolet observations.

Dr. Mordrid

[Brian R.]

This is cool stuff. Where can I sign up?

[Greebe]

Originally posted by Brian R.
This is cool stuff. Where can I sign up?

http://www.savethehubble.org/petition.jsp

[Dr Mordrid]

While I can understand the PR and emotional reasons to save Hubble, I can't justify it on scientific grounds save for the lag between it going out of service and the JWST and others coming online. The economics alone say put the money elsewhere.....

Dr. Mordrid