It takes roughly 365 days, or 1 year, for the Earth to complete its orbit around the Sun. Although it is an elliptical orbit, it is almost circular, so there is only a slight difference between the closest and farthest points from the Sun throughout the orbit. The two-dimensional plane occupied by the Earth's orbit is called the ecliptic.
To complete its orbit in 365 days, the Earth travels around the Sun at a speed of about 67,000 miles an hour. The changing yearly seasons are the result of the Earth's orbit around the Sun combined with its own rotation and the 23.5-degree tilt away from the perpendicular of that rotational axis. The Earth's tilt remains fixed; it always points to the pole star, Polaris. This causes the Earth's top and bottom halves, the Northern and Southern Hemispheres, to be tilted away from the Sun during opposite points in the yearly orbit. This results in the change of seasons and accounts for why the seasons are reversed on either side of Earth's equator.
In terms of mass, the Sun is about 330,000 times the mass of the Earth. It is almost a perfect sphere with a diameter about 109 times the Earth's and accounts for approximately 99.86 percent of the Solar System's total mass.Learn More
When the Earth makes an orbit around the sun, NASA refers to it as a revolution. It takes Earth 365.25 days to make a complete revolution around the sun.Full Answer >
Uranus follows an elliptical orbit around the sun that takes 84.3 Earth years to complete. The length of a planet's year is determined by its distance from the sun. Uranus travels at an average distance from the sun of just over 19 times that of Earth.Full Answer >
The eight described planets all orbit the Sun at different distances; Mercury is the closest planet to the sun, followed by Venus, then Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The distances of the planets are normally measured in kilometers, because scientists use metric measurements. However, scientists also use a unit called an “astronomical unit,” which is equal to the distance between Earth and the sun.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 >