Sun. Sep 17th, 2023

# Glossary of Terms: Elliptical Orbit An elliptical orbit is a type of orbit that is commonly observed in celestial bodies. It is an orbit that is not circular but rather takes the shape of an ellipse. This type of orbit is observed in planets, moons, asteroids, and comets. In this article, we will delve deeper into the meaning of an elliptical orbit and its characteristics.

An elliptical orbit is defined as an orbit in which the distance between the two foci is constant. The two foci are the points that are located at the two ends of the major axis of the ellipse. The major axis is the longest diameter of the ellipse, while the minor axis is the shortest diameter. The distance between the two foci is equal to the length of the major axis.

One of the characteristics of an elliptical orbit is that the speed of the object in orbit changes as it moves around the ellipse. The object moves faster when it is closer to the focus than when it is farther away. This is due to the conservation of angular momentum, which states that the product of the object’s mass and velocity remains constant as it moves around the ellipse.

Another characteristic of an elliptical orbit is that the object in orbit experiences varying gravitational forces as it moves around the ellipse. When the object is closer to the focus, it experiences a stronger gravitational force than when it is farther away. This is due to the inverse square law of gravity, which states that the force of gravity between two objects is inversely proportional to the square of the distance between them.

The eccentricity of an elliptical orbit is another important characteristic. The eccentricity is a measure of how elongated the ellipse is. It is defined as the ratio of the distance between the two foci to the length of the major axis. An orbit with an eccentricity of zero is a circular orbit, while an orbit with an eccentricity of one is a parabolic orbit.

The period of an object in an elliptical orbit is also different from that of a circular orbit. The period is the time it takes for the object to complete one revolution around the ellipse. The period of an object in an elliptical orbit is longer than that of a circular orbit because the object moves slower when it is farther away from the focus.

Elliptical orbits are observed in many celestial bodies in our solar system. For example, the orbits of the planets in our solar system are all elliptical. The eccentricity of the planets’ orbits varies, with Mercury having the most eccentric orbit and Venus having the least eccentric orbit. The Moon also has an elliptical orbit around the Earth, with an eccentricity of 0.0549.

In conclusion, an elliptical orbit is a type of orbit that is not circular but rather takes the shape of an ellipse. It is characterized by varying speeds, varying gravitational forces, and an eccentricity that measures how elongated the ellipse is. Elliptical orbits are observed in many celestial bodies in our solar system, including planets, moons, asteroids, and comets. Understanding the characteristics of elliptical orbits is important for studying the motion of celestial bodies and for space exploration.