Chapter 02: Earth from a Larger Perspective

Question 1

Formation of the universe

Answer 1

Big Bang about 14bya

All elements, but mostly Hydrogen and Helium

Validated by the Red Shift

Constantly expanding

Question 2

Origin of the solar system

Answer 2

Originated around 4.6 bya

Nebular Hypothesis:

• counterclockwise rotation of gas & dust
• sun & planets form via accretionary disc
• mostly Hydrogen and Helium

Question 3

Terrestrial planets

Answer 3

Small, dense, rocky

Mercury, Venus, Earth, Mars

Question 4

Gas giants/jovian planets

Answer 4

Large, mostly gas

Jupiter, Saturn, Uranus, Netpune

Question 5

The sun

Answer 5

Yellow dwarf star (G2)

Fusion of Helium and Hydrogen creates energy

Electromagnetic/solar energy

Drives hydrologic cycle

Controls our climate

Will die in about 5 by

Question 6

Comets

Answer 6

< 6 miles in diameter

Melting ice creates the tail

Orbits can take millions of years

Considered seeds of life, as they transport/deposit ice/water

Question 7

Asteroids

Answer 7

Composed of rock & metal

Diameters of several meters up to hundreds of kilometers

Last signifigant impact: 65 mya (end of Cretaceous period)

Question 8

Meteroid

Answer 8

Rocky/metallic

Smaller than asteroid or planet

Question 9

Meteorite

Answer 9

Hits the Earth’s surface

Radiometric dating helped determine the Earth’s age

Question 10

The moon

Answer 10

Controls tides

Minimize’s Earth’s wobble on its axis

Stabilizes the climate

Allowed for evolution

Question 11

Earth origin

Answer 11

Formed 4.6 bya

Life started 3.5 bya

Life started as extemophile bacteria (deep sea vents, Antarctic ice, rocks deep in ground)

Question 12

Solar system hazards

Answer 12

Electromagnetic radiation (endless stream of solar energy, from which ozone layer protects us)

Ozone depletion caused by CFC’s (chlorofluorocarbons), resolved with Montreal Protocol of 1987

Gamma ray burst (short bursts of high energy via random locations, released by distant galaxies)