shawn001
Well-Known Member
What a silly point ?
This is one statement from Nasa
The learners will view the planets in the solar system rotating around the sun. they will also list the types of objects that comprise the solar system.
The Solar System and Beyond | NASA
Orbit and Rotation of the Earth
This animation compares the orbital motion of Mercury with its rotation. Like the Earth, Mercury spins on its axis while orbiting the Sun and both motions are in the counter-clockwise direction as seen from the north poles of either planet. This means that if you were living on the northern hemisphere of either planet, the Sun would rise in the east and set in the west. Unlike the Earth, though, Mercury's spin rate, which affects the length of a solar day, is not much faster than its orbital speed. One full orbit of Mercury (that is, one Mercury year) takes about 88 Earth days, while one rotation of Mercury about its axis takes two-thirds of this period, or about 59 Earth days. That is, for every three revolutions on its axis, Mercury completes two full orbits around the Sun, a relationship that planetary scientists call 3:2 spin-orbit coupling. The combination of these orbital and spin motions also means that a solar day on Mercury,
Orbit / Rotation
This is very cool just in general and shows just how important orbits are and how weird we know they can get with our observations. Meanwhile back on Earth some have accepted the Earth orbits the sun and the moon is in a tidal orbit.
The Moon's Orbit and Rotation
The Earth's Moon is the fifth largest in the whole solar system, and is bigger than the planet Pluto. The Moon has a nearly circular orbit (e=0.05) which is tilted about 5° to the plane of the Earth's orbit. Its average distance from the Earth is 384,400 km. The combination of the Moon's size and its distance from the Earth causes the Moon to appear the same size in the sky as the Sun, which is one reason we can have total solar eclipses.
It takes the Moon 27.322 days to go around the Earth once. Because of this motion, the Moon appears to move about 13° against the stars each day, or about one-half degree per hour. If you watch the Moon over the course of several hours one night, you will notice that its position among the stars will change by a few degrees. The changing position of the Moon with respect to the Sun leads to lunar phases.
Have you ever heard the term the 'far-side' of the Moon? Because of the effect on the Moon of tidal forces due to the Earth, the same side of the moon always faces the Earth. In other words, it takes the Moon the same amount of time to rotate around once as it does for the Moon to go around the Earth once. Therefore, Earth-bound observers can never see the 'far-side' of the Moon. Tidal forces cause many of the moons of our solar system to have this type of orbit.
The Moon's Orbit and Rotation - Windows to the Universe
Not to mention how the moon was formed in the early universe by a massive collision with Earth by a planet the size of Mars.
How the Universe Works Extreme Orbits