Mercury’s orbit

Definition

Mercury's orbit is the path that the planet Mercury follows around the Sun. It is highly eccentric and inclined compared to other planets in the Solar System.

5 Must Know Facts For Your Next Test

1. Mercury has the most eccentric orbit of all the planets, with an eccentricity of 0.2056.
2. The orbital period of Mercury is approximately 88 Earth days, making it the shortest year of any planet in our Solar System.
3. Due to its proximity to the Sun and its elliptical orbit, Mercury experiences significant variations in temperature and solar radiation.
4. Mercury’s orbit is inclined at about 7 degrees to the plane of Earth's orbit (the ecliptic), which is unusually high among the planets.
5. The perihelion precession of Mercury's orbit was one of the key pieces of evidence supporting Einstein's General Theory of Relativity.

Review Questions

• What is the eccentricity value of Mercury's orbit?
• How long does it take for Mercury to complete one orbit around the Sun?
• What significant astronomical theory was supported by studying Mercury’s orbital precession?

Related terms

Perihelion:

The point in an orbit closest to the Sun.

Aphelion:

The point in an orbit farthest from the Sun.

Orbital Inclination: The tilt of a planet's orbital plane compared to a reference plane, usually Earth's ecliptic.