43
In radio astronomy, the Very Long Baseline Array (VLBA) is a system of ten identical radio telescopes which are operated together as an array. The VLBA is the largest astronomical instrument in existence and is capable of producing images with an angular resolution of about 0.001 arcseconds. That is equivalent to the ability to see a penny on the surface of the Moon from Earth!
The VLBA is located in Hawaii, Mexico, New Mexico, Arizona, and St Croix in the Virgin Islands. It has been used to study quasars, pulsars, gamma ray bursts, black holes, and other astrophysical phenomena.