Name the planets as they go around the sun. Objects in Our Solar System

Essential Vocabulary Rotation – the time it takes to spin on its axis This makes one DAY Revolution – the time it takes to orbit the sun once This makes one YEAR

The Inner Planets Mercury, Venus, Earth and Mars Known as terrestrial planets because they are made of rock Revolve around the Sun and rotate on their axis Closest planets to the Sun

The Outer Planets Jupiter, Saturn, Uranus, and Neptune Gas Giants – composed mostly of Hydrogen and Helium All have rings Revolve around the sun and rotate on their axis.

NOT TO SCALE!

The Sun A ball of glowing gas! Largest thing in our solar system –99.8% of the mass of the solar system No solid surface –75% Hydrogen and 25% Helium Rotates on its axis every 25 – 38 days Located in the center of the solar system

The Moon Our moon is named Luna Spherical About 2400 miles across. All moons are made of rock. Moons orbit their planets in the same direction as the planets’ rotations

Galilean Moons The largest of the many moons of Jupiter The largest of the many moons of Jupiter Discovered by Galileo Galilei on Jan. 7, 1610 Discovered by Galileo Galilei on Jan. 7, 1610

Galilean Moons Among the most massive rocky objects in the Solar System, with a radius larger than Mercury or any of the dwarf planets.

Galilean Moons IoIo (3,642 km) With over 400 active volcanoes, Io is the most geologically active object in the Solar System. Io EuropaEuropa ( km) The smooth surface includes a layer of ice, while the bottom of the ice is theorized to be liquid water. Europa GanymedeGanymede (5262 km) largest natural satellite in the Solar System, a salt-water ocean is believed to exist nearly 200km below Ganymede's surface, sandwiched between layers of ice. It has a thin oxygen atmosphere. Ganymede CallistoCallisto (4820 km) Callisto is is surrounded by an extremely thin atmosphere composed of carbon dioxide and probably molecular oxygen. Investigation revealed that Callisto may have possibly a subsurface ocean of liquid water at depths greater than 100 kilometers. Callisto

Meteoroids Meteors are rocky fragments of comets, planets, moons, or asteroids. Meteors are rocky fragments of comets, planets, moons, or asteroids. Travel through space without an orbit. Travel through space without an orbit.

Meteors Meteoroids that have entered an atmosphere Meteoroids that have entered an atmosphere Friction with the molecules in the atmosphere cause it to burn Friction with the molecules in the atmosphere cause it to burn Commonly called “shooting stars” Commonly called “shooting stars”

Meteorites Any part of a meteoroid that survives passage through the atmosphere and lands on the surface of a planet or a moon. Any part of a meteoroid that survives passage through the atmosphere and lands on the surface of a planet or a moon. Largest meteorite found on Earth Hoba, Namibia

Comets Mixture of ices (both water and frozen gases) dust, and rocks Mixture of ices (both water and frozen gases) dust, and rocks Have an elliptical orbit around the sun Have an elliptical orbit around the sun –When they are in the inner solar system the radiation from the sun causes a tail to form. Due to solar winds, the tail always points away from the sun Due to solar winds, the tail always points away from the sun

Asteroids Left over materials from the formation of the Solar System Left over materials from the formation of the Solar System Composed of rock or metal Composed of rock or metal Smaller than a planet but larger than a meteor Smaller than a planet but larger than a meteor No evidence of an atmosphere No evidence of an atmosphere

Asteroid Belt Most are located in the asteroid belt between Mars and Jupiter: 2 – 4 AU Most are located in the asteroid belt between Mars and Jupiter: 2 – 4 AU probably more than a million probably more than a million