17.1 Comparing size and distance

• The Sun is by far the largest object in the solar system.

• One astronomical unit (AU) is equal to 150 million km, or the distance from Earth to the Sun.

17.2 The planets

• The planets are commonly classified in two groups.

• The terrestrial planets include Mercury, Venus, Earth, and Mars.

• The gas giants include Jupiter, Saturn, Uranus, and Neptune.

Planet Activity

• Create a crossword puzzle with words describing a planet. Cross word puzzle must include 10 down and 10 across.

• Draw a cartoon to explain a planet. At least 10 frames, colored and neat.

 • Create a mural or collage of a planet. Include a 2-paragraph explanation.

 • Research a planet and make a diary of that experience as if you were there.

Include location, type, and use your 5 senses.

 • Create a children's book. Use your creativity. Must include pictures and

basic story line

 

• Write a two-page paper that discusses the differences of two planets.

17.2 Mercury

• Mercury, the closest planet to the sun, is the second smallest (after Pluto) in both size and mass.

17.2 Venus

• Venus appears as the brightest planet in the evening sky and is the third brightest observable object (after the sun and moon).

17.2 Earth

• Earth is a small, rocky planet with an atmosphere that is made of mostly nitrogen (78 percent N2) and oxygen (21 percent O2).

17.2 Mars

• The fourth planet out from the sun, Mars appears as a reddish point of light in the night sky.

17.2 Jupiter

• The fifth planet out from the sun, Jupiter is by far the largest.

• Jupiter’s mass is greater than the combined mass of all of the other planets.

• With 63 known moons, Jupiter is like a mini solar system.

17.2 Saturn• Saturn, at almost

10 times the size of Earth, is the second largest planet.

• The most striking feature of Saturn is its system of rings and like Jupiter, has many natural satellites.

17.2 Uranus

• The seventh planet from the sun, Uranus can barely be seen without a good telescope and was not discovered until 1781.

17.2 Neptune• Neptune, the eighth

planet from the sun, is the outermost of the gas planets.

• It was discovered in 1846 and its discovery almost doubled the diameter of the known solar system because of its great distance from the sun.

17.2 Comparing the planets