a natal planetary position or chart. Resolution: the quality of being able to separate or distinguish close objects from each other. The ability of a telescope to resolve the component stars of a distant galaxy or a multiple star system is directly proportional to the diameter of its aperture, i.e., how wide its lens or mirror is. The unaided human eye can resolve objects in detail about 1 arc minute across. Telescopes in the mid-20th century were capable of resolving images to 1 arc-second: the size of a dime seen from 2.3 miles away. The Hubble Space Telescope increased that resolution to about 0.1 arc-second, and the advent of radio telescopes has allowed astronomers to resolve images as fine as 0.001 arc-seconds. VLBI (or Very Long Baseline Interferometry) is a technique used by radio astronomers to obtain extreme detail. Instead of using a single radio dish, telescopes are linked together in arrays across whole countries or even continents. When the signals are combined in a specialized computer, the resulting image has a resolution equal to that of a telescope whose diameter is equal to the separation of the component antennas that are furthest apart.