World's Largest Radio Telescope Network Goes Live

[mickw]

The world's largest collection of radio telescopes is being tied together for 24 hours starting today to observe more than two hundred energetic galaxies known as quasars.

During those 24 hours, 35 telescopes on all seven continents will observe 243 distant quasars in an effort to improve the precision of the reference frame scientists use to measure positions in the sky.

The quasars, galaxies with supermassive black holes at their cores, are profuse emitters of radio waves, and also are so distant that, despite their actual motions in space, they appear stationary as seen from Earth.

This lack of apparent motion makes them ideal celestial landmarks for anchoring a grid system, similar to earthly latitude and longitude, used to mark the positions of celestial objects

More:   http://www.space.com/scienceastronomy/091118-largest-radio-telescope.html