From: utzoo!decvax!cca!toense@Nbs-Pl@sri-unix
Newsgroups: net.unix-wizards
Title: seconds in a day
Article-I.D.: sri-unix.4050
Posted: Fri Nov 12 23:29:33 1982
Received: Tue Nov 16 03:11:54 1982

From: Robert Toense <toense@Nbs-Pl>
Date:  4 Nov 1982  9:49:43 EST (Thursday)
There are 24*60*60 seconds in a solar day.  For celestial navigation, 
you must use a sidereal day or 23 hours, 56 minutes, 4.09 seconds
of mean time.  The early orbital flights lasted about 4.5 hours which
means that the earth rotated about one quarter degree farther than you
thought during this time.  At the latitudes where these flights
came down, this is close to 15 nautical miles.

-R. Toense