Lecture 3

Question 1

Solar Nebular Disk Model

Answer 1

States that the sun, the planets and all other objects in the solar system formed from nebulous material billions of years ago. Currently accepted paradigm of solar system formation.

Question 2

Nebula

Answer 2

Enormous cloud of dust and gas occupying the space between stars and acting as a nursery for new stars.

Question 3

Supernova

Answer 3

Massive explosion triggered by a star. One of the final stages in the lifecycle of a star

Question 4

Protostar

Answer 4

The very earliest stage of star formation.

Question 5

Star

Answer 5

Any massive self luminous celestial body of gas that shines by radiation derived from its internal energy sources

Question 6

Accretion

Answer 6

Objects being formed by many smaller pieces brought together

Question 7

Planetesimal

Answer 7

Objects formed by accretion which are large enough to generate their own gravity (1km in size or greater)

Question 8

Solar winds

Answer 8

Waves of charged particles (electrons, protons and others). Interact with other atoms and structures in the developing solar system.

Question 9

Frost line

Answer 9

At a certain distance from the sun, the suns heat is no longer enough to vaporize or melt water (water freezes)

Question 10

Inner core

Answer 10

Solid ball, currently believed to be composed mainly of iron and nickel

Question 11

Outer core

Answer 11

A liquid layer composed mainly of iron and nickel

Question 12

Lower mantle

Answer 12

Composed mainly of rock

Question 13

Upper mantle

Answer 13

Composed mainly of rock

Question 14

Crust

Answer 14

A very thin layer; where life exists on the planet

Question 15

Plate tectonics

Answer 15

The movement of portions of the crust and upper mantle of the Earth.
Responsible for the movement of continents, generation of new crust, recycling or old crust.
Earth is the only planet that we know of that has plate tectonics.

Question 16

Late Heavy Bombardment

Answer 16

A large number of asteroids collided with the planets in the inner solar system

Question 17

Rare earth

Answer 17

Earth is truly rare; there are only a few planets with complex life per galaxy

Question 18

Habitable zone

Answer 18

A distance from the central star where liquid water and gaseous CO2 can exist

Question 19

Radiometric dating

Answer 19

A method used to determine how old an object is by measuring the amount of radioisotope the object contains against the decay product it contains

Question 20

Relative-age dating

Answer 20

The process of determining if one rock or geologic event is older or younger than another, without knowing their specific ages
Determining the relative order of past events, without determining their absolute age

Question 21

Carbon dating

Answer 21

Measuring the age of a once living thing by measuring the amount of carbon inside of it

Question 22

Half-life

Answer 22

The time needed for a quantity of a substance to reduce by half of its initial value