We explain what an orbit is and what its meaning is in the area of chemistry. Also, elliptical orbits and orbits of the Solar System.

An orbit can have various shapes, be it elliptical, circular, or elongated.## What is an orbit?

In physical, the orbit is the trajectory described by a body around another, around which it revolves by the action of a central force, such as the Gravitational force in the case of stars celestial. It is about the trajectory that an object traces when moving around a center of gravity by which it is attracted, in principle without ever hitting it, but not moving away completely.

Orbits are since the seventeenth century (when Johannes Kepler and Isaac Newton formulated the basic physical laws that govern them) an important concept for the understanding of the movement at universe, especially with regard to the celestial stars and also to subatomic chemistry.

An orbit can have various shapes, be it elliptical, circular, or elongated, and it can be parabolic (shaped like a parabola) or hyperbolic (shaped like a hyperbola). Be that as it may, every orbit comprises the following six Keplerian elements:

- Inclination of the plane of the orbit, represented by the sign i.
- Length of the ascending node, represented by the sign Ω.
- Eccentricity or degree of deviation of a circle, represented by the sign e.
- Semi-major axis, or half the longest diameter, represented by the sign a.
- Argument of perihelion or periastrum, the angle that goes from the ascending node to the periastrum, represented by the sign ω.
- Mean anomaly of the time, or the fraction of weather elapsed orbital and represented as angle, represented by the sign M0.

## Orbit in chemistry

Each atomic orbital is expressed with a number and a letter.Inchemistry, we speak of orbits regarding the movement of electrons around the nucleus of theatoms, due to the difference in electromagnetic charges they present (negative in theelectrons and positive at the core of protons Y neutrons). These electrons do not have a defined trajectory, but are classically described as orbits known as atomic orbitals, depending on the degree ofEnergy they host.

Each atomic orbital is expressed with a number and a letter. The number (1, 2, 3… up to 7) denotes the energy levels with which theparticle it moves, while the letters (s, p, d and f) denote the shape of the orbital.

## Elliptical orbit

An elliptical orbit is one that instead of a circle, traces an ellipse, that is, a flattened and elongated circumference. This figure, the ellipse, has two foci, where the central axes of each of the two circles that compose it would be; Furthermore, this type of orbit has an eccentricity greater than zero and less than one (0 is equivalent to a circular orbit and 1 to a parabolic).

Every elliptical orbit has two notable points:

- Periapsis. The closest point on the orbital path to the central body around which the orbit is traced (and located at one of the two foci).
- Apoapsis. The farthest point on the orbital path from the central body around which the orbit is traced (and located at one of the two foci).

## Orbits of the Solar System

The planet Mercury is the one with the most eccentric orbit, perhaps because it is closer to the Sun.The orbits described by the stars of our Solar system they are, as in most planetary systems, of the more or less elliptical type. In the center is the star of the system, our Sun, whose gravity keeps the planets in movement; while the kites in their respective parabolic or hyperbolic orbits around the Sun they do not have a direct link with the star. For their part, satellites of each of the planets also trace orbits around each one, as does the Moon with the Earth.

However, the stars also attract each other, generating mutual gravitational disturbances, causing the eccentricities of the orbits to vary with time and with each other. For example, the planet Mercury is the one with the most eccentric orbit, perhaps because it is closer to the Sun, but it is followed on the list by Mars, much further away. Venus and Neptune, on the other hand, have the least eccentric orbits of all.

## Earth orbit

The Earth, like its neighboring planets, orbits the Sun in a slightly elliptical path, which takes approximately 365 days (one year) and which we call the motion of translation. Saying displacement it occurs at about 67,000 kilometers per hour.

At the same time, there are four types of possible orbits around the Earth, for example, for artificial satellites:

- Low Orbit (LEO). From 200 to 2,000 km of the planetary surface.
- Mean orbit (MEO). From 2,000 to 35,786 km of the planetary surface.
- High Orbit (HEO). From 35,786 to 40,000 km of the planetary surface.
- Geostationary orbit (GEO). At 35,786 km from the planetary surface. This is the orbit synchronized with the Earth's equator, endowed with zero eccentricity and at which an object appears immobile in the sky for terrestrial observers.