Prototype Telescopes Complete Key Test

Matthew Sparkes writes "Two prototype antennas for the world's largest array of millimeter-wave telescopes have passed a key test, working to track and image Saturn for more than an hour. Ultimately, ALMA (Atacama Large Millimeter/submillimeter Array) is expected to resolve details 10 times finer than the Hubble Space Telescope when it is completed in 2012."

Comments

Hubble censored? Data encrypted?

[Firethorn]

I have no problems believing that the control data is encrypted for the hubble. For one thing, you don't want others taking it over.

As for the data, I'd imagine that it'd be compressed, encoded, and multiplexed to the point that you'd need special equipment that no normal HAM operator* would have, much less the settings needed to sort it all out and make sense of it.

For public key stuff - that's more computationally intense than private key military encryption methods. Remember, we're talking about systems where a 386 would be considered 'high end'.

*I'm not saying that you're a 'normal' Ham operator, Crawler, but we're talking the space industry here.

Apples and oranges

[$RANDOMLUSER]

Ultimately, ALMA (Atacama Large Millimeter/submillimeter Array) is expected to resolve details 10 times finer than the Hubble Space Telescope when it is completed in 2012.

Except that one is a radio telescope and one is an optical telescope.

Re:the use of space-telescopes?

[Falladir]

The people who design and build these telescopes don't have unlimited budgets. If they use up their grant money sending a telescope into space, they can't hire as many graduate students, for instance. While saving money isn't the primary concern for the principal investigator, it's certainly a priority.

The reason WMAP was a space telescope was, as you said, so that it wouldn't have to look through the water-vapor in the atmosphere. ACT and ALMA will be earth-based because it's impractical to send telescopes as big as those into space.

In summation, don't worry: astronomy funds are not being wasted!

Re:the use of space-telescopes?

[Tablizer]

I'm actually beginning to wonder if space-telescopes still have their use

It is hard to separate hype from reality. Hubble is used as the benchmark in many claims because of its popularity. But as you partially pointed out, there are some rough-spots in Earth-based techniques:

* Spectrum coverage: some important frequencies are blocked by the atmosphere.
* Ecology: Earth scopes are accused of messing up mountain peaks and views and "sacred lands".
* Guide-stars: Some earth-bound techniques require bright guide-stars near a scene to compensate for atmospheric distortion. This limits their use in dim portions of the sky.
* Southern hemisphere: It is hard to see all portions of the sky well from any given point on Earth.
* Newness: Many of the hi-res earth-scope techniques are new and complicated. Without a reference point, such as Hubble images, they may be collecting unintended artifacts of the technology.

But it is an interesting issue to consider.

Re:the use of space-telescopes?

[Gil-galad55]

Land-based telescopes are gaining much ground, especially when it comes to data volume. The dataset for the LSST (Large Synoptic Survey Telescope) will most likely be measured in exabytes when all is said and done, and it simply isn't possible to send that volume of data home via telemetry. However, space-based telescopes most definitely have their place.

Two exciting ones are Planck, which will make extremely precise measurements of the CMB (Cosmic Microwave Background) and--if we're lucky--LISA, a gravity wave telescope that will open a completely new part of the universe to us. The science prospects for LISA are staggering, and it is simply impossible to build an interferometer with a 5 million km arm length on the ground!