Global Internet Telescope Tops Hubble's Resolution

satorchi writes " The Arecibo Observatory together with the European VLBI Network have used the internet to make a real-time transatlantic synthesis telescope. Data from the individual telescopes was transfered via the internet, and processed in real time by the central processing station at the Joint Institute for VLBI in Europe. 9 terabits were transfered during the 20 hour experiment, and the resulting synthesised telescope had a resolution of 20 milliarcseconds, about 5 times better than the Hubble Space Telescope (HST). This level of detail is equivalent to picking out a small building on the surface of the Moon!"

Comments

Does this mean

[The_Mr_Flibble]

we can look for the place where the moon landings took place to finaly debunk all those sceptics ?

Re:Does this mean

[Traa]

we can look for the place where the moon landings took place to finaly debunk all those sceptics ?

If the comment was sincere then tell me how exactly you would want to convince someone who doesn't listened to reason. Hopefully you see the contradiction.

Here is my view of the universe:

The Real Universe
- what really happens. What really is/was/shall be
- population 0

The Physical Universe (feel free to call it something else like 'personal universe')
- The rules we come up with that describe as best we can "The Real Universe".
- population 1, you. This is what you believe to be the truth.

The Imaginative Universe
- everything else.
- When several people discuss their 'Physical Universe' the stuff that doesn't overlap, or hasn't been agreed upon.
- population: everyone

This overview explains a few things. It explains that it is not possible to 'force' someone to change their Physical Universe view. If you do convince someone of your view you simply described it fitting with their own rules. You will find people in life with some really weird rules.

my $0.02 philosophy

9 TB / 20 hours

[mirko]

How heavily has this impacted the transatlantic Internet communications, during these 20 hours ?

Costs

[tcdk]

Does anybody have an idea about the cost of such a telescope (if you where to build a new one) compared to the Hubble?

Maybe a space based replacement for Hubble isn't needed...

Re:Costs

[Lord Prox]

Maybe a space based replacement for Hubble isn't needed...

You are forgeting the first rule of govt spending. Spend big. What we need is a space based version of this "limited technology demo"

This is not a replacement for Hubble

[Animaether]

The title of this story is stupendously moot. It's like saying "oil tanker carries more weight than freight train". Yes, I'm sure it does. It also doesn't go across land.

Very similarly, this is an antenna (radio astronomy) not a telescope (optical astronomy).

Even if it were a telescope, it would still be limited by atmospheric distortions (hence why you'd want one in space).

And even if it were a telescope in space, you'd probably end up with WEBB - which lacks sensors in many of the ranges that Hubble does cover.

All of the above lead up to at least two results...
1. Less scientific data

and, arguably more important as it drives the public's opinion/enthusiasm/taxpaying-willingness/etc.

2. Far less pretty pictures.

I suggest doing a search for Hubble on Slashdot and reading the +5 Insightful/Informative posts, as many of them go into detail as to why many of the proposals simply aren't a replacement for Hubble, and why it either should stay up - or a proper replacement be built.

Make that...

[thrill12]

The moonlander.

An integrating idea.

[Anonymous Coward]

Suppose that you wanted to detect a very faint object. You could aim your telescope at a given point in the sky for a couple of hours each night. You could integrate the image over a six month period. That should give you a baseline of 186 million miles never mind a paltry couple of thousand miles.

One of my favorite experiments is to take a sine wave buried under about 20 dB of noise. By integrating over a long enough period, the signal emerges beautifully. (of course it has zero bandwidth) The neat thing about this is that your detector only has to resolve one bit; you still get a nice sine wave out. This should work for detecting dim stars and I'd be suprised if they didn't do it. Do they? Any astronomers out there?

Re:An integrating idea.

[Christopher Thomas]

Suppose that you wanted to detect a very faint object. You could aim your telescope at a given point in the sky for a couple of hours each night. You could integrate the image over a six month period. That should give you a baseline of 186 million miles never mind a paltry couple of thousand miles.

The catch is that you have to know both your position to sub-wavelength precision and the current time to within a fraction of a wavelength period in order to make measurements over that time and distance range.

For 1e9 Hz signals, this means knowing the position of the earth to within a centimetre or two, and knowing the time to about one part in 1e17 (the best atomic clocks I've heard of are 1e14-1e15, and 1e13-1e14 is probably the best you can actually get your hand on). We _might_ know Earth's position that accurately, but I'm not sure (ask an astronomer). Also, the source being studied has to be emitting coherent light at a stable frequency over the same time period for interferometry-after-the-fact like this to work (whereas it just has to be stable for about a twentieth of a second for earth-based radio interferometry).

So, using Earth's orbit as a baseline and integrating over very long time periods doesn't work for most radio sources (it might work for an extremely stable lower-frequency source). Pulsars might be predictable enough, if you apply known models to compensate for spin-down over the observation period. This would let you get a better angular fix on them than you would be able to do by other means.

What I'm waiting for is for a constellation of sun-orbiting radio telescopes to be built with a multi-AU baseline. Sources would have to be stable for hours, but you could get really interesting images of the storms on nearby stars and the magnetospheres of the planets around those stars by this technique. In practice, you'd probably have a cluster of telescopes in each of the orbits, so that you could do interferometry of more rapidly-changing events with a shorter baseline.

Re:The real conspiracy

[Peyna]

They'd claim you stuck them in a simulator and drove it to a fake moon that you dropped them off on to make them think they were really on the moon; evidenced by your not letting them traverse the entire surface.