The follow is a list of terms you’ll find in the Astronomical Calendar

  • Apogee – The Moon is at its farthest point from the Earth for this orbit.
  • Perigee – The Moon is at its closest point to the Earth for this orbit.
  • Conjunction – Two or more bodies appear to be near each other in the sky.
  • Inferior Conjunction – Occurs when an inner planet passes between the Earth & Sun.
  • Superior Conjunction – Occurs when a planet passes behind the Sun as seen from Earth.
  • Opposition – When a body is opposite the Sun in the sky.
  • Stationary – Bodies outside of Earth’s orbit appear to stop and then travel backwards for a short period while Earth is passing it.  Once Earth has passed it the body stops and then resumes its forward motion.  The two times when a body stops it is considard stationary.
  • Moon North 22.5 – Moon at its northern most point for this orbit and the degrees.  In this example 22.5 deg.
  • NEA – Near Earth Asteroid. An asteroid that passes close to Earth, the distance compared to the moon’s distance (LD-Lunar Distance), and its size.

Satellite Passes

Example Entry:

2 Jan -3.5

Rise:18:45:16 10 NW

Peak: 18:48:23 82 NNW

Finish: 18:48:23 82 NNW

The 1st line is the date and magnitude (measure of brightness).  The rise, peak, and finish times follow, with the altitude and the direction.  In this example, it rises as 18:45 (6:45pm) 10 deg. above the northwest.  It reaches its’ peak at 18:48 (6:48pm) 82 deg. above the North-North-West.   In this example the satellite enters the Earth’s shadow at the peak and thus fades away from view.

Iridium Flare

Example Entry:

Iridium 23 – Alt: 68 Az: 52 (NE)

Iridium satellites are communications satellites that have 4 reflectives panels (antenna) on them.  When conditions are right a brief, bright glint of sunlight can be seen reflecting off the panels.   These glints are the flares.  In this example Iridium Satellite 23 is producing the glint.  It can be seen at an Altitiude of 68 degrees high at an Azimuth of 52 deg. or generally in the northeast.

Note: Satellite and Flare predictions times are valid only for central Arkansas.