Square degree

Examples

• The full moon covers only about 0.2 deg² of the sky when viewed from the surface of the Earth. The Moon is only a half degree across, so the moon's disk covers a circular area of: × ², or 0.2 square degrees. The moon varies from 0.188 to 0.244 deg² depending on its distance to the Earth.
• Viewed from Earth, the Sun is roughly half a degree across and covers only 0.2 deg² as well.
• It would take times the full moon to cover the entire celestial sphere.
• Assuming the Earth to be a sphere with a surface area of 510 million km², the area of Northern Ireland and Connecticut represent a solid angle of 1.1 deg² and 1.2 deg², respectively.
• The largest constellation, Hydra, covers a solid angle of, whereas the smallest, Crux, covers only 68 deg².