General Info Inner Planets (From Sun): Mercury, Venus, Earth, Mars. Outer Planets (From Sun: Jupiter, Saturn, Uranus, Neptune. Definitions: Rotation: “The act of rotating; a turning around as on an axis.” Orbit: “The curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.” Revolve: “to move in a circular or curving course or orbit: The earthrevolves around the sun..” Axis: “The line about which a rotating body, such as the earth, turns.” (Dictionary.com) There are eight planets and three dwarf planets. Outer planets are mostly composed of gas, while inner planets are mostly composed of rock, they are also separated by a asteroid belt. There are more craters found on inner planets because the asteroids and meteroites fly around the sun, which make them flying closer too the inner planets, making them sometimes collide.
General Info (Contd.) To be considered a planet, the planet would have to form its orbit itself, revolve around the sun, and lastly form a sphere by gravity. A dwarf planet is considered as a planet, but isn’t large enough to be considered a planet, it also has not formed a orbit around the sun. The three dwarf planets are: Eris Pluto Ceres
Mercury Mercury is the closest planet to the Sun. Mercury was photographed by Mariner 10 it photographed 45% of its surface, and it showed us that Mercury had a lot of craters just like our moon. It has cliffs as high as 3 km, it was formed when mercury shrank. Since Mercury is close to the Sun the temperatures can go from 425C to -174C, it also causes the atmosphere seen in Mercury. Some of the gases seen in it’s atmosphere are hydrogen, helium, oxygen, sodium, calcium, potassium, and water vapor. The three processes that shaped Mercury, tectonic activity, erupting volcanoes, and meteorites, asteroids, etc., impacting into Mercury.
Venus The second nearest to the Sun is Venus. Which means from Earth, it is the brightest planet, therefore it is called “Evening Star”. They also call Venus “Earth’s twin”, because the size and mass of Venus is around the same as Earth’s. Maat Mons is the highest volcano on Venus, lava flows across hundreds of kilometers. The clouds on Venus are so dense little of the sunlight reaches the surface of Venus. The light that does get through, heats up the surface and gives off heat to the atmosphere, a lot of the heat is absorbed by carbon dioxide in Venus’ atmosphere. So this causes a greenhouse effect like the one on Earth. Since the greenhouse effect is so serious, the temperatures go from 450C to 475C. Venus’ atmosphere is mostly composed of carbon dioxide, hydrogen, sulfur, and oxygen. Retrogade Rotation means that the planet revolves in the opposite direction as other planets. Venus rotates really slowly, so one day is shorter than a year. The Sun would appear to rise from the east because Venus rotates the opposite way, from east to west. The reason why Venus is the hottest planet, is because of it’s greenhouse effect (explained above), and its distance from the Sun.
Earth Earth is the third closest planet to the Sun. Earth’s atmosphere is composed of, oxygen, nitrogen, argon, water vapor, carbon dioxide, neon, methane, krypton, helium, xenon, hydrogen, nitrous oxide, carbon monoxide, nitrogen dioxide, and sulfur dioxide make up our atmosphere. It is about 150 million km from the Sun. It has water, which can support life. Earth’s atmosphere causes most meteors to burn up in the atmosphere before reaching the surface. It’s ozone layer protects life from the Sun’s radiation. Earth is on a 23.5 degree tilt. Earth’s magnetic filed is formed by Earth’s rotation and its metal core. Earth’s satellite is the Moon.
Mars The reason why Mars is red, because the iron oxide in the soil give a reddish color. Mariner 9 showed canals most likely carved by flowing water. It also discovered the largest volcano in the solar system, a volcano called Olympus Mons, but it is probably extinct. They also discovered large rift valleys. Mars’ atmosphere is thinner than Earth’s, it is made up of mostly carbon dioxide with some nitrogen and argon. The temperatures go from -125C to 35C. Mars has a 25 degree tilt, so that means like Earth it has a seasonal variation. Scientists have found samples of bacteria on rocks on Mars. Earth has two small moons: Phobos Deimos
Jupiter Callisto Ganymede Io Europa Jupiter is the largest planet in our solor system. It’s atmosphere is mostly made of hydrogen, helium, ammonia, methane, and water vapor. The clouds on Earth are very colorful, it also has continuous storms, such as the “Great Red Spot”. It also has 63 different moons but the biggest four are: Io, Europa, Ganymede, Callisto. Io gets heat up by the gravitational pull that it is known as the most active volcano in our solar system. Jupiter’s shape is formed because Jupiter spins really fast, causing the equator to bulge and the ends to be smoother. Jupiter’s atmosphere is mostly composed of hydrogen, helium, sulfur, and nitrogen.
Saturn Saturn is the second largest planet in the solar system. Saturn’s atmosphere is mostly composed of hydrogen and helium. Much like Jupiter’s atmosphere it also contains ammonia, methane, and water vapor. When you get deeper into the atmosphere the gases become liquid hydrogen and liquid helium. Saturn has several rings, each large ring is made up of thousands of smaller rings. Saturn’s rings are composed of thousands of ice and rock particles, which may have been caused by the break up of small moons. There are around 47 moons orbiting Saturn. The largest moon on Saturn is a moon called Titan, it is larger than Mercury. Saturn is very light, making it able to float on water. The seasons on Saturn last about 30 times longer than the seasons on Earth.
Uranus Uranus is a large planet, it has 27 moons with dark rings. It’s largest moon is Titania, it has many deep valleys and craters. Uranus has 11 rings surrounding it’s equator. The atmosphere there is composed up of hydrogen, helium, and a little methane. Methane give the turquoise color that we see on Uranus. It is blue because the methane absorbs the red and yellow light, and the clouds reflect the green and blue light. Uranus is mostly made up of rocks and ices. It’s axis is very different than other planets, its axis is tiled on the side, some scientists believe that it collided with something which caused it to be tilted like this, so Uranus’ rotation is now on it’s side. Uranus’ atmosphere is mostly composed of hydrogen, helium, and methane.
Neptune Neptune’s atmosphere is composed of hydrogen and helium, with small amounts of methane, just like Uranus.Also like Uranus, the methane gives Neptune its turquoise color. Also like Jupiter it has dark colored storms, one of them is called the Great Dark Spot. Neptune’s surface is mostly composed of rock and different types of ices made from methane and ammonia. Neptune has at least 13 moons, it’s biggest one is called Triton. Scientists believe that Triton was originally a dwarf planet, or another moon of Uranus or Pluto, but it ended up getting sucked into Neptune’s gravitational pull. Neptune has dark rings which are pretty young and won’t last very long either.
Pluto Pluto is the smallest planet within the other planets, it also is the farthest away from the Sun too. It has a diameter of 2,300 km, it also takes about 248 years for one orbit around the Sun. It has a thin atmosphere, it also has a solid, icy/rocky surface. Pluto has 3 moons: Charon,, Hydra, and Nix.The largest of the 3 is Charon, it has a diameter of 1,200 km and orbits Pluto from 19,500 km away. By using a spectroscope, scientists found out that Pluto contained methane frost, and Charon contained water frost. Charon is about half the size of Pluto.
Ceres One revolution in Ceres, is about 4.6 Earth years. For a period of time, it was considered an asteroid because it was among a lot of asteroids. On the surface of Ceres, water, ice, carbonates, and clays are found.
Eris Eris’ original name was Xena. One revolution on Eris is about 557 Earth years. It has a moon called Dysnomia. It is not considered a planet yet, because it has not cleared out it’s orbit yet.