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 elements sodium (Na) and potassium (K) have been detected in the Moon's atmosphere using Earth-based spectroscopic methods, whereas the isotopes radon -222 and polonium -210 have been inferred from data obtained by the Lunar Prospector alpha particle spectrometer.
The Moon orbits the Earth and the Earth-Moon system orbits the Sun. The nodes are the points in the orbit of the Moon where it crosses the orbit of the Earth-Moon system around the Sun. When the Moon is at one of these nodes, the Moon, Earth, and Sun are lined up so that an eclipse can occur.