5 articles for "Astronomical"
Astronomical Day [Astro*Index]A 24-hour day, beginning at midnight (0h). Thus, noon is 12:00, 1:00 PM = 13:00. The first second of the day is: 00:00:01. The last second of the day is: 23:59:59. Also called 24-hour, or "military" time, which is in common use in European countries.
See also:Astronomical Time [Astro*Index]
♦ Time ♦ Day
Clock or Civil Time.
See also:Astronomical Unit AU [Astro*Index]
♦ Time ♦ Clock Time ♦ Civil Time
(au).
A system of measurement used within our solar system based on the mean distance between the Earth and the Sun – 92,957,130 miles (149,600,000 km).
The relation of planets and other bodies to the Sun is expressed using the au as a measuring stick. For example, the mean distance of Saturn from the Sun is 9.54 au; the semimajor axis of the Earth's orbit is 1.000000031 au.
See also:Astronomical Unit AU [Munkasey M.]
♦ Ellipse
A unit of long distance measure used within the Solar system.
It is based upon the mean Earth to Sun distance and is equal to 93 million miles (150 million km).
See also:Astronomical Unit [DeVore]
♦ Ellipse
Mean distance of Earth to Sun, or 92,900,000 miles; employed as a unit for indicating intra-solar system distances.
See also:
♦ Time ♦ Clock Time ♦ Civil Time
Astro*Index Copyright © 1997 Michael Erlewine
[ TOP ]