The inner and outer planets all follow an elliptical orbit, share the same orbital plane, are spherical and contain some of the same elements. Besides those attributes, each planet is very different.Know More
The inner planets are those that exist between the sun and the asteroid belt. They are:
The outer planets are those that are between the asteroid belt and the end of the solar system. These are:
The outer planets are known as Jovian or gas giants. They are much larger in size than the inner planets and are primarily composed of gases that surround a liquid metal core.
The inner planets are all smaller and denser than the outer planets. They are mostly solid and composed of rock rather than gas.
The reason for the difference in the size, density, and composition of the planets is that the gravity of the sun tends to attract heavier, solid elements, such as heavy metals, while lighter gases, such as hydrogen, helium, nitrogen, and oxygen, are not pulled as strongly inward.
The elements that exist in all of the planets are iron and nickel. Mercury, the planet closest to the sun, is almost entirely made of these two elements, while the outer planets only have trace amounts located in their core.Learn more about Planets
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 >
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 >
Mercury has the shortest orbit of any of the planets in the solar system. Because it is the closest planet to the sun, its orbit takes only 88 days.Full Answer >
As the furthest orbiting planet in the Solar System, Neptune has the longest year, taking 164.8 Earth years to complete a single orbit of the Sun. Prior to its reclassification as a dwarf planet in 2006, Pluto was the planet with the longest year, equal to about 248 Earth years.Full Answer >