1 The English language is constantly adding words to its repertoire. 2  Each year you may see a few creep into the vernacular that don't appear in the dictionary. 3  They could appeaâ¦. 4  Helping a Young Girl Understand Her First Menstrual Period Most girls experience their first menstrual period between the ages of 12 and 13.
It is also the length of a sidereal day -- the time it takes the earth to rotate 360Â°. A sidereal day could be measured using fixed stars. In conclusion the actual period of rotation of the earth is 23 hours 56 minutes and 4 seconds or 86,164 seconds.
Rotation is the time it takes for a planet to spin once on its axis. This is different from a planetâs revolution, which is the time it takes for a planet to orbit around another object (i.e. the Sun). So while it takes the Earth one day (24 hours) to rotate once on its axis, it takes one year (365.256 days) to revolve once around the Sun. Earth and Venusâ orbit compared. Credit: Sky and Telescope