Radio Telescopes Linked in Southern Hemisphere Available to Purchase

Another long baseline radio interferometer is in operation, the first one in the southern hemisphere. The linkup (similar to those described in PHYSICS TODAY, November 1967, page 69) is between two NASA Deep Space Stations in Australia, one near Woomera in South Australia and one near Canberra in New South Wales. Its baseline is more than $9×106$ wavelengths long at 2295 MHz. Preliminary observations of radio source 3C 273 show that the interferometer has an angular resolution better than 0.008 sec of arc.