A Telescope as Big as the Earth

Roland Piquepaille writes "A week ago, seven telescopes around the world were linked together to watch a distant galaxy called 3C273 in real time and create a single world telescope. The data from these telescopes, which are located in Australia, China and Europe, was streamed around the world at a rate of 256 Mb per second. One of the Australian researchers involved in the project said that it was the first time that astronomers have been able to instantaneously connect telescopes half a world apart. He added that 'the diameter of the Earth is 12,750 km and the two most widely separated telescopes in our experiment were 12,304 km apart.'"

Comments

Unfortunately...

[Anonymous Coward]

...all data from the Shanghai telescope was filtered and replaced with promotional material for the Peoples Republic of China. Apparently the galaxy bears a striking resemblance to Chairman Mao.

FYI

[Gabrill]

This technique is being used.

Re:FYI

[moderatorrater]

I read up on it, but I didn't see the downsides of this technique being discussed. What's the drawback of using this technique as opposed to an actual earth-sized telescope?

Re:FYI

[Bemopolis]

Total amount of signal gathered. That is to say, you gather less rain with a few buckets scattered across a field ratherthan a field-sized bucket. On the plus side, since you are monitoring simultaneously at different sites, you can compare the signals among the antennae to get the same spatial resolution of a telescope the size of the Earth. Compare to the VLA, a much smaller version of the same technique.

Re:FYI

[Nyeerrmm]

There are two reasons to make a really big telescope (whether optical, radio, or even x-ray). FIrst you pick up more photons, allowing you to pick up dimmer, more distant objects and get less noisy data. The second is that you get improved angular resolution, since the limiting factor for resolution on a good telescope is the diffraction of light, a consequence of the wave nature. Simply, the angular resolution is approximated very well by Rayleigh's Formula:

Resolution(radians) = Wavelength/Diameter

When you do this kind of technique, you increase the angular resolution that can be picked up to that of a full telescope over the area (if designed properly to get the middle resolutions as well). However, as others have mentioned, you don't get the full number of photons, which means you have to increase the imaging time or allow for much high SNRs. However, this is still very useful for getting high resolution images of fairly bright objects.

Central Obstruction

[Liquidrage]

Wow! And I thought SCT's had a large central obstruction.

Ok. That might be the geekiest joke in the histroy of /.
:(

All at once

[Blitz22]

I for one, welcome our giant eyed, galactic..... I soviet Russia, the world telescopes .... Scientist can finally peer deep into goat..... be gentle.

Heh

[Scott Lockwood]

Imagine a Beowolf Cluster of these!

Re:Were they looking in the optical range?

[Robotbeat]

This is in the radio range, not the optical range. The summary misled me to thinking it was in the optical range, which would be an impressive achievement, indeed! The news of this story is that it was done in real-time, over a network connection, instead of by shipping data from each radio telescope site on hard-drives to a location be processed later.

Re:Cool

[Gloy]

You haven't tried Google Sky, then?

Re:OK

[evanbd]

It's a radio telescope; the atmosphere is almost irrelevant. This gives a very large effective size for diffraction purposes, meaning the resulting images can be much more finely resolved.

Lightspeed Broken!

[ec_hack]

One of the Australian researchers involved in the project said that it was the first time that astronomers have been able to instantaneously connect telescopes half a world apart.

This is the real story - FTL communications!

A source of hope

[athloi]

We have problems on earth, but most of them will never be solved. Poverty will always exist. Stupidity will always exist. So will criminality, alcoholism, drug addiction, and failure. We can either spend our time obsessing over the negative, or we can choose to explore space and find a new future. I'm glad that we continue to probe space, to consider sending up ships, and most all, that we keep space exploration alive in our minds as a source of hope.

No, it runs Windows ME.

[PalmKiller]

Just seconds after the feeds started the galaxy imagery was somehow lost and replaced with the standard BSOD screen.

Wrong it is not 4.22 years.

[arthurpaliden]

Actually light from the closest know star takes about 8 minutes to get to the earth.

Re:Wrong it is not 4.22 years.

[MollyB]

From the photons' POV it takes no time at all. (ducks)

Re:Really?

[powerpants]

Dammit, how about a spoiler alert! Not everyone's a speed reader.

Re:Really?

[SatanicPuppy]

Jesus, if you haven't read it after 1250 years, you're going to have to live with the spoilers!