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
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 >
Eris, the dwarf planet whose orbit is beyond Neptune's orbit, has one small moon named Dysnomia. The dwarf planet was first spotted in 2003 and confirmed in 2005.Full Answer >
As of July, 2014, there are 1,235 active artificial satellites currently in orbit around the Earth. The only natural satellite that orbits Earth is the moon.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 >