How to calculate an aphelion distance?

Answer 1

When an object is closest to the Sun in its orbit around the Sun, that is called perihelion; the farthest point in the orbit is called aphelion. The generic names (making reference to any central body, and not the Sun specifically) are periapsis and apoapsis (or apapsis).

Answer 2

The "helion" part refers to Helios, the Greek name of the Sun.

"Peri-" means "close to" OS "perihelion" means "the closest point to the Sun in the orbit".

"Aphelion" is the farthest point away from the Sun in the orbit.

Sometimes scientists use "gee" to refer to the Earth, so "perigee" is the closest point to Earth in an orbit, and "apogee" is the "farthest point from Earth in the orbit".

Answer 3

It isn't so much that you "need" perihelion and aphelion as it is that these words exist and you might as well understand them.

"Helios" is the Greek word for "Sun". "Peri-" is the prefix meaning "close" and "ap-" is a prefix meaning farther away. So "perihelion" is the closest point that an object in orbit comes to the Sun, and aphelion is the point at which it is furthest away from the Sun.

Answer 4

Every closed orbit is an ellipse, with the primary body at one focus. (Kepler's first 'law'.) Every planet in the solar system travels in an elliptical orbit. The orbit of Venus is the least eccentric, but it's still not circular ... even Venus has a minimum and maximum distance from the sun. An orbit has no aphelion only if it's perfectly circular. If it's not a perfect circle, then it has a minimum distance from the sun, as well as a maximum distance. The point in the orbit at which the distance to the sun is maximum is called "aphelion". ========================================= "Perihelion" is the orbital point where the distance to the sun is minimum.

Answer 5

Astronomers use the terms perihelion and aphelion to describe the points of an object's orbit around the Sun when they are closest to and farthest away from the Sun, respectively. In the case of the planet Earth, with the Sun as the focal point around which it orbits, the difference between the distances at perihelion and aphelion are much less than some of the other planets.

Answer 6

First of all, planets don't orbit the Sun in a true circle. Planets orbit the Sun in an oval shape, called an elliptical orbit. (When the planet is closer to the Sun it moves faster than when it is farther from the Sun.)

When the planet is at its closest point to the Sun it is called its perihelion, and at the greatest distance, it is called the aphelion.

The words also apply to other members of our solar system, such as asteroids and comets.

That is essentially it. =)

Answer 7

Aphelion and Perihelion occur because the shape of the Earth's orbit is elliptical. The Earth's distance from the Sun at perihelion is about 146 million

kilometers.

The distance from the Sun at aphelion is about 151 million km.

These words can also be used for the orbits other planets, asteroids, comets, etc.

Answer 8

Aphelion is Earth's furthest point from the Sun, whereas perihelion is the closest.

These words are also used for any other objects that orbit our Sun.

Answer 9

Aphelion ... lowest orbital speed.

Perihelion ... highest orbital speed.

Answer 10

Perihelion is the point at which a planet is closest to the Sun in it's elliptical orbit. Aphelion is when it is furthest.