Solar System

By Yoyo Yu

Science 8C

General Information• Rotation: when an object spins once on its axis• Revolve: when a smaller object goes around a larger object once • There are 8 planets (inner and outer, but not dwarf)• Mercury, Venus, Earth, and Mars are the inner planets• Jupiter, Saturn, Uranus, and Neptune are outer planets • Inner planets are solid spheres of rocks, as they were continuously

hit by the asteroids and meteorites for the first 600 million years• Outer planets are huge gaseous spheres, and with rings.• Orbit: the pathway that a planet goes on • The 3 requirements to be considered as a planet are: 1) it must

have an orbit that goes around the sun, 2) it must have enough mass to make itself sphere-like because of its gravity, 3) and has cleared its orbit around the sun

• Dwarf planet: “planets” that met the first two requirements but failed the third one

• Pluto, Ceres, and Eris are examples of dwarf planets

Inner Planets

Mercury

• Mercury’s atmosphere is caused by the short distance from the sun

• Mercury’s atmosphere is consisted of helium and sodium

• Mercury’s surface was shaped by three processes: 1) impact cratering, when large objects from space collided with Mercury 2) volcanism, where lava had covered the surface, 3) tectonic activity, where Mercury’s crust moved in order to adapt to the planet’s cooling and contraction. 

Venus• Venus is also referred as the “Evening

Star” because it is the brightest planet that can be seen from earth during nighttime

• Two elements that can be found in Venus’s atmosphere are carbon dioxide and sulfuric acid

• Retrograde rotation is when a planet rotates clockwise, which is a characteristic that only Venus have

• Venus rotation takes 243 days, while its revolution is 225 days

• The sun would appear to rise in the west and set in the east is because of its clockwise rotation

• Venus is the hottest planet in the solar system is because of the ongoing volcanic activity which had provided the sulfuric acid for the atmosphere

Earth• The elements that make up Earth’s

atmosphere are nitrogen, oxygen, argon,  water vapor, carbon dioxide, neon, methane, krypton, helium, xenon, hydrogen, nitrous oxide, carbon monoxide, nitrogen dioxide, sulfur dioxide, and ozone.

• The atmosphere protects us by absorbing solar radiation before it reaches Earth, and meteor collision

• Earth’s rotational tilt is 23.5 degrees• The liquid metallic core of earth causes

the magnetic field on Earth• The nature occurring satellite of Earth is

the Moon

Mars

• Meteorites that hit Mars had ancient bacteria

• The primary element of Mar’s atmosphere is carbon dioxide

• Mars appear red because its soil contained iron-laden clay

• Olympus Mons is one of largest volcanoes in the solar system: 60 km wide and 26 km high

• Mars’s two satellites are Phobos and Deimos.

Outer Planets

Jupiter• Due to the fast rotation of Jupiter,

the planet’s poles are flattened and bulge in the equator

• The elements that make up Jupiter’s atmosphere are hydrogen, helium, sulfur, and nitrogen.

• The Giant Red Spot is a hurricane-like storm

• Jupiter have 50 named satellites• Jupiter’s satellite, Io, is volcanically

active, and have the highest temperature than any body in the solar system (except the sun)

Saturn

• Saturn’s atmosphere was made out of hydrogen and helium

• Astronomers have a theory that Saturn’s ring is composed of the particles of natural occurring satellites that had been broke down

• The ring is composed of water ice and dust

• Saturn has a very low density (lower than any planet in the solar system) that allows it to flow on water

Uranus

• Uranus’s rotation was different because of it’s 98 degrees tilt, so to us it looks like Uranus is rotating on its side

• Uranus’s atmosphere is made out of hydrogen, helium, and methane

• Uranus has 27 known satellites

Neptune• Neptune’s atmosphere is made

out of ammonia, helium, and methane.

• Neptune has thirteen known satellites, four are within its ring.

• Triton is Neptune’s biggest satellite, and astronomer believed that it wasn’t originally Neptune’s satellite. Astronomers believe that Triton became Neptune’s satellite due to Neptune’s gravitational pull.

Dwarf Planets

Pluto

• Pluto’s three moons are Charon, Nix, and Hydra.

• By using the spectroscope, scientists learned that Pluto has methane frost, and water frost on Charon.

• Charon was unusual because of its size; it’s half the size of Pluto.

Ceres

• It takes around 4.6 Earth years for Ceres’s revolution around the sun

• Ceres was once considered as an asteroid because it’s orbit is within the Asteroid Belt

• Scientists found a liquid water layer on Ceres’s interior

Eris

• Before it had Eris as its official name, Eris was nicknamed Xena

• It would take 557 Earth years for Eris to revolve around the sun

• Eris’s moon is named Dysnomia

• Eris is not considered to be a planet because it did not clear out its orbit