Chromaffin cell. Chromaffin cells, also pheochromocytes, are neuroendocrine cells found mostly in the medulla of the adrenal glands (located above the kidneys) in mammals.
The Moon has no appreciable atmosphere. The sky is always black and the radiation from the Sun strikes with full force on the surface of the Moon. The lack of atmosphere produces temperature extremes on the Moon that range from -250 degrees F in the dark to +250 degrees F in the light.
Orbit of the Moon. The Moon orbits Earth in the prograde direction and completes one revolution relative to the stars in approximately 27.323 days (a sidereal month). Earth and the Moon orbit about their barycentre (common center of mass), which lies about 4,600 km (2,900 mi) from Earth's center (about 34 of the radius of Earth). On average, the Moon is at a distance of about 385,000 km (239,000 mi) from Earth's centre, which corresponds to about 60 Earth radii.