The document provides information about the planets and dwarf planets in our solar system. It describes the 8 major planets and 5 dwarf planets, and discusses their key characteristics such as composition, atmosphere, rotation, and moons. Examples include Mercury having no atmosphere and many impact craters, Venus rotating backwards and having extreme temperatures, and Pluto being the first and largest dwarf planet discovered.

1. PLANETS OF OUR SOLAR SYSTEM BY: Geenie Choy 8C

2. General Information Revolve: The action of a smaller object circling around a larger object. Rotate: The action of an object spinning on its axis. There are 8 planets and 5 dwarf planets found. INNER PLANETS: Mercury Venus Earth Mars OUTER PLANETS: Jupiter Saturn Uranus Neptune Their differences: Inner planets have many craters due to asteroids and meteorites. Outer planets are much larger and are made of gas Orbit: The path which an object (planet, satellites, etc.) follows 3 REQUIREMENTS: Must orbit around the Sun Round due to large mass and gravity Cleared orbit DWARF PLANETS orbit around the sun and are big enough to be round, but they do not have a cleared orbit. -Pluto -Ceres -Eris

3. Shaping Mercury: Craters were formed when huge objects hit the surface—impact cratering Lava erupted from volcanoes and spread across the surface—volcanism Moving plates in the crust due to constant cooling and contracting on the planet— tectonic activity So close to the Sun that it has no substantial atmosphere. The atmosphere contains helium and sodium . Craters MERCURY

4. VENUS “ Evening Star” --the clouds covering Venus reflect sunlight easily, allowing Venus to be seem extremely bright The atmosphere contains carbon dioxide and sulfuric acid *acts as a greenhouse— traps heat this causes Venus to be the hottest planet in the solar system R etrogade rotation: when the planet spins in a clockwise direction on its axis. Since Venus has an opposite rotation than the other planets, the Sun would appear to rise in the west and set in the east. It has a longer day than year because one retrogade rotation takes 225 Earth days . This means Venus takes a longer time to spin than revolves around the Sun.

5. EARTH Atmosphere: They protect us from harmful solar radiation by absorbing it, and meteors . 23.5 degrees tilt of axis The Earth’s metallic core in the center and its continuous spin on its axis created the magnetic field. Earth’s satellite is the Moon which rotates around it.

6. MARS Scientists examine meteorites from Mars for proof of ancient bacteria and signs of living things. Primary element: 95% carbon dioxide The iron-rich clay that covers Mars gave the planet its red color. OLYMPUS MONS: tallest volcano in the solar system on Mars peak: 26 km over base shield volcano=gentle slope 20 times wider than height Satelites- Phobos and Deimos Irregular shape Believed to be asteroids

7. JUPITER The poles are flatten and the middle swell out because of the rotation . ATMOSPHERE: Hydrogen Helium Nitrogen sulfur THE GREAT/GIANT RED SPOT: A storm that can be seen from space; it was first spotted when scientists discovered Jupiter. Astronomers believe it is caused by a storm-system on Jupiter 50 moons and 13 more unofficial satellites found. Io (one of Jupiter’s satellites) is volcanically active which causes it to have an extremely high tempereture.

8. SATURN ATMOSPHERE: H yrogen Helium Scientists think that Saturn’s rings are formed by natural satellites breaking up . RINGS: Ice, water, and dust from satellites which broke up near Saturn T hickness:10-100 meters D ifferent brightness G aps in between some rings, others are braided Saturn could FLOAT due to its extremely low density  Seasons last more than 7 Earth years!!!

9. URANUS UNIQUE due to its 98 degrees tilt this caused Uranus to look like it rotates on its side . For known natural satellites, Uranus has 27 . ATMOSPHERE: H ydrogen H elium M ethane

10. NEPTUNE ATMOSPHERE: A mmonia H elium M ethane 13 known satellites with 4 circling Neptune inside the rings . Triton-the largest satellite of Neptune M ade of ice and rock Believed to be not originally a satellite, but it was forced to orbit around Neptune by Neptune’s gravity. Why did astronomers thought it was not a satellite? R etrograde orbit D ensity Composition

11. DWARF PLANETS

12. PLUTO THREE MOONS: Charon — half of Pluto, orbits close to the dwarf planet Nix — farther away Hydra — farther away Using the spectoscope they found that Pluto has methane frost and Charon has water frost . Charon is extremely large for a moon (half of Pluto). It is also bluer than Pluto.

13. CERES 1 year = 4.6 Earth years Ceres became known as an asteroid in 1802. This was because many other objects orbiting between Mars and Jupiter were named as asteroids. Since Ceres also orbits in the same area, it became known as an asteroid, too. Surface is covered with clay , water ice , and carbonates . This helped differentiate Ceres from the other members of the asteroid belt.

14. ERIS O riginal name: Xena , referring to the popular television show during the time Eris was found I t takes 557 years for Eris to make one orbit around the Sun. MOON: Dysnomia — the daughter of Eris, cause of lawlessness It was not named a planet because Eris did not clear its path of orbit , which meant it didn’t meet one of the requirements for a planet. Dysnomia

15. THE END. All information from: http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/planets.html