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.' So he's almost right by cliaming they created 'a telescope almost as big as the Earth.'
You can see above a map showing the location of the seven telescopes involved in this networking experiment (Credits: Image created by Paul Boven, Joint Institute for VLBI in Europe (JIVE) in The Netherlands; Satellite image: Blue Marble Next Generation, courtesy of NASA Visible Earth) For more clarity, here is a link to a CSIRO page where you'll have access to a much larger version of this map (3,456 x 2,048 pixels, 3.81 MB).
The CSIRO (Commonwealth Scientific and Industrial Research Organisation) news release adds that the initial data was captured by a single 22-meter dish located near Coonabarabran in New South Wales, known as the Mopra telescope. This telescope is operated by the Australia Telescope National Facility (ANTF) and you can find more details here.
The observations were then transmitted to Xi'an, China, 'where they were watched live by experts in advanced networking at the 24th APAN (Asia-Pacific Advanced Network) Meeting,' and streamed to Europe.
The technique used to link the various telescopes is called Very Long Baseline Interferometry (VLBI, Wikipedia link). According to Tasso Tzioumis, VLBI operations and development manager at CSIRO's ANTF, this technique used to take weeks or months. "'We used to record data on tapes or disks at each telescope, along with time signals from atomic clocks. The tapes or disks would then be shipped to a central processing facility to be combined,' Dr Tzioumis said."
For more information, you can take a look at the European VLBI Network. And if you want to see some pictures of the telescopes involved in this experiment, you can read this Environment News Service article, "First Instant World Telescope Views Distant Galaxy." You'll also find that the EXPReS project, known formally as the Express Production Real-time e-VLBI Service, aims to implement up to 16 simultaneous 1 Gb per second network connections between the central processor at JIVE and partner telescopes across Europe, Asia, Australia, South Africa, South America and the United States by 2009.
It looks like astronomers are highly connected people...
Sources: CSIRO news release, September 5, 2007; and various websites
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