Solar System: The Planets

By: Emily Huang 8B

General Information:• Define revolve: when a smaller object circles around a larger one.• Define rotate: when an object spins on its axis• How many planets have been found in our solar system? Eight

planets.• Which planets are the inner planets? Mercury, Venus, Earth, and

Mars. • Which planets are the outer planets? Jupiter, Saturn, Uranus, and

Neptune. • What is the difference between the inner and outer planets?

The inner planets are close to the Sun and are made of solid rock. The outer planets are farther from the Sun, are large, are made of gas, and have rings.

• Why are more craters found on the inner planets compared to the outer planets? In the first 600 million years that they existed, the inner planets were often hit by asteroids and meteorites

• Define orbit: a specific path that planets/satellites/etc. follow.• What are three requirements to be considered a planet? 1. the

object must orbit the Sun 2. have enough mass in order to become a round shape (by its own gravity) 3. have the path of the orbit cleared around the Sun.

• What is a dwarf planet? Dwarf planets are planets that meet all requirements of a planet except the third one.

• List the three dwarf planets. 1. Pluto 2. Ceres 3. Eris

THE INNER PLANETS

Mercury• What causes Mercury’s atmosphere? Since

Mercury is so close to the sun, there isn’t really an atmosphere.

• What two elements can be found in the atmosphere? Helium and Sodium.

• What three processes shaped Mercury? 1. impact cratering – when large objects crashed into it which led to crater shapes. 2. volcanism – lava flooded it. 3. tectonic activity – Mercury’s crust moved.

Venus• Why is Venus referred to as the “Evening

Star”? It is the brightest of the planets and can be seen from earth.

• What two elements can be found in the atmosphere? Carbon dioxide and sulfuric acid.

• What is retrograde rotation? It is a rotation that is clockwise; opposite of all other planets.

• Why is a day on Venus longer than a year on Venus? It takes 225 Earth days for Venus to orbit the Sun, and it takes 243 Earth days to rotate. why

• If you were standing on Venus, would the Sun appear to rise in the west and set in the east? Since Venus has a retrograde rotation (clockwise), the Sun would rise in the west and set in the east.

Earth• What elements make up our atmosphere? Oxygen, nitrogen,

argon, water vapor, carbon dioxide, neon, methane, krypton, helium,

xenon, hydrogen, nitrous oxide, carbon monoxide, nitrogen dioxide,

sulfur dioxide, and ozone.

• What two things does our atmosphere protect us from? It

protects us by absorbing harmful solar radiation and also protects us

from meteors.

• What is the rotational tilt of Earth? 23.5 B

• What produces the magnetic field on earth? Since our core is

made of molten-iron nickel, the metallic core causes it.

• What is the satellite of the Earth? The Moon.

Mars• What evidence do scientists have to life

on Mars? There are pieces of Mars (meteorites) on Earth and small ancient bacteria are on it, so there may have been life on Mars.

• What is the primary element of the atmosphere? Carbon dioxide.

• Why does the planet appear to be red? The planet contains iron. (iron-laden clay)

• What is Olympus Mons? The tallest volcano/mountain in the whole solar system

• What are two satellites of Mars? Phobos and Deimos.

THE OUTER PLANETS

Jupiter• How is the shape of Jupiter affected by

the planets rotation? The planet is flattened in the poles and bulged out in the equator part.

• What elements make up Jupiter’s atmosphere? Hydrogen, helium, sulfur, and nitrogen.

• What is the Giant Red Spot? A hurricane-like storm that has been on Jupiter since it was first seen.

• How many new natural satellites does Jupiter have? It originally has 50, but there are 13 new ones.

• What is interesting about Jupiter’s satellite lo? It is volcanically active and has a hotter surface than any other planet in the solar system.

Saturn• What elements make up Saturn’s

atmosphere? Hydrogen and helium.• What may have caused Saturn to have

rings? Scientist think that it may have been formed by Saturn’s satellites after they broke down.

• What is the composition of the rings? Water ice and dust particles.

• Why could Saturn float in water? Its density is very low; it has the lowest density (planet) in our whole solar system.

Uranus• What the different about Uranus's

rotation? It rotates sideways. (tilted 98 B)• What elements make up Uranus’s

atmosphere? Hydrogen, helium, and methane.

• How many known satellites does Uranus have? 27 satellites.

Neptune• What elements make up Neptune’s

atmosphere? Ammonia, helium, and methane.

• How many known satellites does Neptune have? 13 satellites.

• What is Triton? Explain how astronomers believe Triton became a satellite. Triton is Neptune’s largest satellite. Astronomers think that Triton wasn’t always one of Neptune’s satellites. They think that Neptune’s gravitation pull pulled Triton to orbit around it.

THE DWARF PLANETS

Pluto• What are the names of Pluto’s three

moons? Charon, Nix, and Hydra. • What have scientists learned about

Pluto by using a spectroscope? They know there is methane frost on Pluto, and water frost on Pluto’s satellite, Charon.

• What is so unusual about Pluto’s moon Charon? Pluto and Charon seem to connect to eachother (they might share the same atmosphere). Charon is more blue than Pluto.

Ceres

• How long is one revolution? 4.6 Earth years.• Why was Ceres once

considered an asteroid? There were some objects orbiting between Mars and Jupiter; Sir William Herschel just called them asteroids. • What can be found on

Ceres’ surface? Water ice, carbonates, and clays.

Eris• What was Eris’ original name? Xena.• How long does it take Eris to orbit

the sun? 557 Earth years.• What is the name of Eris’ moon?

Dysnomia.• Why is Eris not considered to be a

planet? Since it doesn’t meet the third requirement. (doesn’t clear out the orbit)

THE END!