this is about planets
2007-01-02 12:00:39 · 6 answers · asked by princessgirl99343 2 in Science & Mathematics ➔ Astronomy & Space
this is about planets and space
2007-01-02 12:01:41 · update #1
a day is the length of time taken for the planet to spin 360 degrees on its axis (all the way round!) and a year is the amount of time taken for the planet to revolve around the sun. the length of daytime and nighttime each day is determined by your location on earth and how much its axis has pivoted with relation to the sun.
2007-01-02 12:02:49 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Hi. On Earth a day is the time it takes for the Sun to pass an imaginary line, called the meridian. Usually it is measured at noon when the Sun is highest in the sky. This is different from a sidereal day which is when a STAR passes the meridian. A solar day is several minutes shorter than a sidereal day. This would apply to each planet as well. A "year" is the time for a planet to orbit the Sun once. It is not an even number of days because the planets are not "gear driven" if that makes sense to you.
2007-01-02 20:40:05 · answer #2 · answered by Cirric 7 · 0⤊ 0⤋
The length of a day on a planet or moon or any other object is determined by how long it takes the planet, etc. to rotate exactly once 360 degrees. For example, a day on Earth is exactly 23 hours 56 minutes 4.04 seconds. A day on Jupiter is 9.92 hours. A day on Mercury is 58.65 Earth days. Etc.
2007-01-02 21:43:00 · answer #3 · answered by bldudas 4 · 0⤊ 0⤋
A "day" is the time it takes a planet to make one full 360-degree rotation around its own axis. One earth day is a little over 24 hours...one Venus day is about 233 earth days! It's different for every planet.
One year is the time it takes a planet to make one full orbit around its sun. It doesn't matter what you pick for the starting point, anywhere in the orbit will do, then just measure the time it takes to get back to that spot. Earth takes 365.2425 earth days to make one orbit around the sun.
2007-01-02 20:04:47 · answer #4 · answered by Anonymous · 1⤊ 0⤋
one revolution of the earth relative to any object directly over-head. stay away from objects to the extreme north or south. which equals something near 23h56m4s. look up GREGORIAN CALANDER and also notice leap year there, additionally, PRECESSION OF THE EQUINOXES will be interesting. and one year is the time it takes the earth to completely orbit the sun.
2007-01-02 21:16:41 · answer #5 · answered by Anonymous · 0⤊ 0⤋
That's like asking "Why are men male and women female?" We just are. The earth rotates on its axis and revolves around the sun at the rates at which it does. No reason--it just does.
Scientists call these quantities "imponderables." It just is so.
2007-01-02 21:55:49 · answer #6 · answered by aviophage 7 · 0⤊ 1⤋