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.
As the Sun sets, the Moon rises with the side that faces Earth fully exposed to sunlight (5).The Moon has phases because it orbits Earth, which causes the portion we see illuminated to change. The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 days. The Moon spends the extra 2.2 days catching up because Earth travels about 45 million miles around the Sun during the time the Moon completes one orbit around Earth. At the new Moon phase, the Moon is so close to the Sun in the sky that none of the side facing Earth is illuminated (position 1 in illustration). In other words, the Moon is between Earth and Sun. At first quarter, the half-lit Moon is highest in the sky at sunset, then sets about six hours later (3).