The nine planets in order are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and, if it's still considered the ninth planet, Pluto. However, not only has Pluto been demoted to a dwarf planet by some astronomers, but its orbit is so eccentric that there are times when it's closer to the sun than Neptune.Know More
The inner planets are Mercury, Venus, Earth, and Mars. They have rocky surfaces. Mercury, the closest planet to the sun, rotates very slowly on its axis in comparison with Earth. It is very hot on the surface that faces the sun and very cold on the side that is turned away from the sun. Because Venus is covered with clouds, it is subject to a runaway greenhouse gas effect that makes it so hot that spacecraft that land there can only function for a few minutes before being destroyed. Earth, in what scientists call the "Goldilocks zone," is just right for life. Mars isn't as cold as the side of Mercury that faces away from the sun, but its atmosphere is thin and made up mostly of carbon dioxide.
The other planets are much larger than the four inner planets. All of them have rings, though the rings around Saturn are the most prominent.Learn more about Planets
It is not possible for all nine planets to align perfectly because the axes around which they rotate tilt at different angles. The planets do end up within 90 degrees of each other about once every 200 years.Full Answer >
The nine planets in the solar system range in size from approximately 3,000 to 140,000 kilometers in diameter. Ranked from smallest to largest the planets are Pluto, Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn and Jupiter.Full Answer >
Various websites dedicated to the solar system have photos of the nine planets. Some of these websites are universetoday.com, nineplanets.org, space.com and popsci.com. Most of the photos online are credited to the National Aeronautics and Space Administration, commonly known as NASA.Full Answer >
The planets in the solar system have temperatures that can often vary from a maximum to a minimum temperature, such as Mercury that has a minimum temperature of -300 degrees Fahrenheit and maximum of 870. These differences in temperatures occur because the side of Mercury that is facing the sun gets very hot since Mercury is so close to the sun, while its dark side does not experience this extreme heat.Full Answer >