The shape of Earth's orbit is an ellipse, which resembles a stretched circle. Earth's orbit lies on the plane of the ecliptic, an imaginary plane in which the sun and the planets move. Earth revolves around the sun in a period of 365 days.
Earth orbits the sun partly because of its own motion and partly because of the sun's gravity. The formation of the solar system was so forceful it shot Earth out on a path that it would still be traveling on if not for the gravity of the sun. The sun's gravity acts like a giant string and keeps Earth on its elliptical orbit.
Earth does not always orbit the sun at the same distance. Perihelion is the spot where Earth is closest to the sun; aphelion is the place where Earth is farthest from the sun. At aphelion, Earth is approximately 156 million kilometers away; at perihelion, Earth is about 146 million kilometers away from the sun.Learn More
Kepler's Third Law states that ?The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit," according to Universe Today. This law has one formula that creates the same result for all planets.Full Answer >
In order to be declared a planet, a celestial body must meet the following qualifications: It must orbit the sun, it must maintain a nearly spherical shape and have the necessary mass for self-gravity so that it does not succumb to rigid body forces, and it must clear the neighborhood around its orbit. All recognized planets in the solar system meet this definition.Full Answer >
The orbit of the planets around the sun is a result of two opposing forces that are held in perfect balance. Planetary inertia serves to carry the planets on a course that would send them out of the solar system were it not for the gravitational attraction of the sun.Full Answer >
Perturbations in the orbit of the planets Neptune and Uranus point to the existence of Planet X in the region of the proto-planet Pluto. Planet X is beyond Uranus and Neptune and likely resides within part of the sky that hosts the constellations Scorpius or Taurus.Full Answer >