The solar system consists of the Sun and eight planets that orbit around it. The Sun is a yellow dwarf star at the center of the solar system that provides energy for life on Earth. The four inner planets closest to the Sun are Mercury, Venus, Earth, and Mars. The four outer planets are Jupiter, Saturn, Uranus, and Neptune. Pluto, once considered the ninth planet, is now classified as a dwarf planet due to its small size.

1. Solar System

2. The Sun is a 4.5 billion-year-old yellow dwarf star
– a hot glowing ball of hydrogen and helium – at
the center of our solar system.
It’s about 93 million miles (150 million
kilometers) from Earth and it’s our solar system’s
only star.
Without the Sun’s energy, life as we know it
could not exist on our home planet.
Sun
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3. Mercury
• Has a revolution period of 88 days.
Has 1000° temperature swings from day to night because there is no
atmosphere to trap heat.
• Is about 1/3 of Earth’s size
• Is about 1/3 Earth’s distance from the sun (0.39 AU)
Mercury

4. Venus
Has retrograde rotation – so the sun rises in the west and sets in the east!
• Reaches 900°F at the surface due to a strong greenhouse effect.
Venus has no moons and takes 225 days to complete an orbit.
Is about the same size as Earth
Is about 2/3 Earth’s distance from the sun (0.72 AU)
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5. Is the only planet known to support life!
Has a surface composed of 71% water.
- Water is necessary for life on Earth.
• Is the basis for the Astronomical Unit (distance
from sun to Earth = 1 AU)
Earth
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6. Mars appears red because of iron oxide, or rust, in its
soil.
• Mars has two moons and takes about two years to
complete an orbit.
• Is about ½ of Earth’s size
Is about 12 times as far from the sun as Earth (1.52 AU)
Mars
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7. • Is the largest, most massive planet.
Takes about 12 years to orbit the sun.
Jupiter has 17 known moons.
Is about 11 times larger than Earth.
• Is about 5 times farther from the sun than Earth
(5.19 AU)
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Jupiter

8. Has many rings made of ice that extend about 260,000 miles
from the surface but are less than 1 mile thick.
• Has 19 known moons
• Takes about 30 years to orbit the sun.
Is almost 10 times larger than Earth
Is nearly ten times farther from the sun than Earth (9.5 AU)
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Saturn

9. • Has 21 known moons
Takes 84 years to complete one orbit.
• Is about 4 times larger than Earth
• Is about 19 times farther from the sun than
Earth (19.1 AU)
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Uranus

10. Takes 165 years to orbit the sun
Has 8 moons
• Is about 3.8 times larger than Earth
Is about 30 times farther from the sun than
Earth (30 AU)
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Neptune

11. Once thought of as usually the furthest planet from the sun.
2/3rds the size of our moon.
Has one large moon, Charon, and two smaller ones, Nix and Hydra.
So cold that oxygen and nitrogen in its atmosphere is frozen solid except
when Pluto is nearer the Sun.
Only planet not visited by a spacecraft.
Pluto takes 248 years to make one orbit around the sun!
Pluto
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