GEOGRAPHY

Circular orbits are the simplest kinds of orbits in celestial mechanics, where an orbiting body remains at constant radius as it travels around a gravitating mass.

This is due, for example, to the fact that when the Earth is closer to the Sun in its elliptical orbit it orbits faster, while when it is further away it orbits slower, averaging to a value equivalent to that of a circular orbit.

Ellipses are closed so the planets we see in elliptical orbits stick around. A circle is a special case of an ellipse and it is theoretically possible for an orbit to be circular. In the real world, a such an orbit is unlikely.

Using the precise data that Tycho had collected, Kepler discovered that the orbit of Mars was an ellipse. In 1609 he published Astronomia Nova, delineating his discoveries, which are now called Kepler’s first two laws of planetary motion.

Orbits are eliptical because of Newtons Law of Gravity (bodies attract each other in proportion to their mass and inversly proportional to the square of the distance between them). All worked out by Kepler some years ago. A circular orbit is a special (and very unlikely) case of an eliptical orbit.

When an object moves around another object in an oval shaped path, it is known to be revolving in an elliptical orbit. All planets move in elliptical orbits around the sun. The Moon also moves around earth in an elliptical orbit.

a year, occurring once every four years, which has 366 days including 29 February as an intercalary day.

Solution : At the Equator, the earth’s rotational motion is at its fastest, about a thousand miles an hour. If that motion suddenly stopped, the momentum would send things flying eastward. Moving rocks and oceans would trigger earthquakes and tsunamis. The still-moving atmosphere would scour landscapes.

Annual motion is the apparent yearly movement of the stars as observed from Earth as a direct effect of the Earth’s revolution around the sun. The sun revolves 360 degrees a year around a path on the celestial sphere called the ecliptic.

Earth basically has two types of motions. They are rotation and revolution. These two motions are responsible for different kinds of phenomena.