MERCURY

VENUS

EARTH

MARS

JUPITER

SATURN

NEPTUNE

SOLAR SYSTEM SUN MOON ASTEROID

THE SOLAR SYSTEM

Our solar system consists of an average star we call the Sun, the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. It includes: the satellites of the planets; numerous comets, asteroids, and meteoroids; and the interplanetary medium. The Sun is the richest source of electromagnetic energy (mostly in the form of heat and light) in the solar system. The Sun's nearest known stellar neighbor is a red dwarf star called Proxima Centauri, at a distance of 4.3 light years away. The whole solar system, together with the local stars visible on a clear night, orbits the center of our home galaxy, a spiral disk of 200 billion stars we call the Milky Way. The Milky Way has two small galaxies orbiting it nearby, which are visible from the southern hemisphere. They are called the Large Magellanic Cloud and the Small Magellanic Cloud. The nearest large galaxy is the Andromeda Galaxy. It is a spiral galaxy like the Milky Way but is 4 times as massive and is 2 million light years away. Our galaxy, one of billions of galaxies known, is traveling through intergalactic space.

Our Solar System

Mercury

Venus

EarthMarsJupiter

Uranus

Neptune

Saturn

Mercury Closest to the sun Smallest planet Rotates once every 59 earth days. One day on Mercury lasts 176 Earth days. Very dry, hot, and almost airless

VenusSecond closest planet to the sun Brightest celestial body besides the moon and sun. Cannot be seen in the middle of the night Can be observed in the east at sunrise and the west at sunset

Earth3rd from the sun 5th largest planet in the solar system More than 4.5 billion years oldHas one natural satellite we call the moon. Oceans cover 70% of Earth’s surface

MarsFourth from the sunOnly planet whose surface can be seen in detail from the Earth Reddish in color, the atmosphere of Mars is made of carbon dioxide

JupiterThe Fifth planet from the sunLargest planet in the solar system Has at least 39 months

SaturnSixth planet from the sun Has at least 31 moonsThe surface on Saturn consists of liquid and gas

UranusSeventh planet from the sun 1st planet discovered with a telescopeAtmosphere is a mixture of Hydrogen, Helium, and methane Does not have a solid surface

Neptune8th and farthest planet from the sunThe atmosphere is mostly hydrogen and helium Has 8 known moons

MoonBigger than PlutoOnly object in the Solar System visited by humans. A lunar month is 29.35 days, 1 new moon to the next. The moon’s gravitational pull on Earth is the main cause of the ocean’s tide.

SunLocated 93,000,000 miles from EarthClosest star to EarthAt least 4.5 billion years old Has a surface temperature of 10,000 degrees and a center temperature of 27,000,000 degrees Fahrenheit.

AsteroidsThe Asteroid Belt is the space between Mars and JupiterIt contains irregularly shaped chunks of debris called asteroidsAsteroids made of rock and metal. Mostly nickel and iron