# What is “Azimuth” and “Altitude”?

A. Those numbers tell you the position of the moon. The Azimuth is basically the same as a compass bearing. It measures, in degrees, where the moon is on the horizontal plane, starting from grid north (not magnetic north) at 0 degrees and moving clockwise. For example, an Azimuth of 90 degrees means the moon is due east; 180 degrees is south; and 270 degrees is west. 360 degrees is equivalent to 0 degrees. But you’ll also want to look at the Altitude to see how far up in the sky the moon is. For example, the moon could be oriented due west at 270 degrees, but that doesn’t mean it is on the horizon. Altitude is measured from an assumed perfectly level horizon (this means that mountains or other obstructions may be in the way), at 0 degrees. An Altitude of 45 degrees is halfway up in the sky, and 90 degrees is straight up. Altitudes can be negative, which simply means the moon is below the horizon at that degree angle. So minus 90 degrees (-90) means the moon is directly “underfoot” (oth