<P> Many deep sky objects such as galaxies and nebulas appear as non-circular, and are thus typically given two measures of diameter: Major Diameter and Minor Diameter . For example, the Small Magellanic Cloud has a visual apparent diameter of 5 ° 20 ′ × 3 ° 5 ′ . </P> <P> Defect of illumination is the maximum angular width of the unilluminated part of a celestial body seen by a given observer . For example, if an object is 40 seconds of arc across and is 75 percent illuminated, the defect of illumination is 10 seconds of arc . </P>

What is the length and width of the moon