Final Review Sheet
• The Earth is
•4.5 billion years old
• Gas & dust pulled together by gravity=rotating disk
• Star & planets form at the same time
• Universe is MUCH older= 14 billion years old
Which of the following best describes the age relationships between the universe, the
Earth, and humans?
•The Earth is really old compared to humans, and really young compared to
• Galaxies appear “red shifted.” This tells us they are moving away from us.
What would a star or galaxy look like if it were moving toward you?
•it would be blue shifted
Birth of Universe and Earth:
• Universe is about 14 billion years old
• Earth is younger..4.5 billion years old
• Earth formed from a rotating disk of gas and dust, as did our entire solar system
• Universe is expanding = red shift of galaxies
• Expansion is speeding up = farther galaxies move faster away
Four Components of the Earth system
• Which one is NOT powered by the sun?
•Geosphere= one quarter of the Earth System is composed of rocks and
Igneous Rocks - rocks that cool and solidify fro magma or lava.
Process : melting → cooling → crystallization/solidification
Magma -below Earth’s surface; Lava-on Earth’s surface
Sedimentary rocks - made up of pieces of other rocks. Require water and/or an
• Mars doesn’t have liquid water on its surface today, but it did in the past. It currently
has a thin atmosphere. Could Mars have sedimentary rocks on