exam 1

Question 1

geocentric

Answer 1

centered on the Earth

Question 2

heliocentric

Answer 2

centered on the Sun

Question 3

horizon

Answer 3

a great circle on a celestial sphere 90° from the zenith

Question 4

zenith

Answer 4

the point on the celestial sphere opposite the direction of gravity (the point directly above the observer)

Question 5

celestial equator

Answer 5

a great circle on a celestial sphere 90° from the celestial poles
- intersects the plane of Earth’s equator

Question 6

celestial poles

Answer 6

points where the celestial sphere appears to rotate
- intersects the Earth’s polar axis

Question 7

celestial sphere

Answer 7

the apparent sphere of the sky centered on the observer

Question 8

circumpolar zone

Answer 8

portions of the celestial sphere near the celestial poles that are either always above or always below the horizon

Question 9

the sun’s annual path on the celestial sphere is the….

Answer 9

ecliptic

Question 10

who recognized that the Earth and Moon are spheres and understood the phases of the Moon?

Answer 10

Aristotle

Question 11

retrograde motion

Answer 11

the apparent westward motion of a planet on the celestial sphere

Question 12

who suggested that Earth is a planet and that all planets circulate around the Sun?

Answer 12

Copernicus

Question 13

1st law of planetary motion

Answer 13

the orbits of all the planets are ellipses

Question 14

2nd law of planetary motion

Answer 14

the straight line joining a planet and the Sun sweeps out equal areas in space in equal intervals of time
- planets speed up when they become closer to the Sun and slow down as they pull away from the Sun

Question 15

3rd law of planetary motion

Answer 15

the square of a planet’s orbital period is directly proportional to the cube of the semi-major axis of its orbit

Question 16

Newtons laws of motion tell us what?

Answer 16

objects at rest will stay at rest and those in motion will continue moving uniformly in a straight line unless acted upon by a force

Question 17

True or false
- The more mass an object has, the stronger the pull of its gravitational force

Answer 17

True

Question 18

True or false
- The gravitational attraction between 2 bodies must be proportional to their masses

Answer 18

True

Question 19

True or false
- Newtons law implies that gravity never becomes 0

Answer 19

True

Question 20

Orbit

Answer 20

the path of an object under the influence of gravity through space

Question 21

Planetary System

Answer 21

a group of planets and other bodies circling a STAR (not sun)

Question 22

What 2 planets were NOT known to the ancients?

Answer 22

Uranus and Neptune

Question 23

Terrestrial planets

Answer 23

relatively small and are primarily composed of rock and metal

Question 24

Jovian planets

Answer 24

large and primarily composed of liquids, gases, and lighter ices

Question 25

Which 2 planets don't have a moon?

Answer 25

Mercury and Venus

Question 26

True or false - When looking at the internal structure of terrestrial planets, the densest metals are in the central core, with the lighter silicates near the surface

Answer 26

True

Question 27

Differentiation

Answer 27

a process by which gravity helps separate a planet's interior into layers of different compositions and densities

Question 28

What is the purpose of the atmospheric insulation?

Answer 28

Keeps heat in

Question 29

Geological activity on a planet is a result of....

Answer 29

a hot interior

Question 30

True or false - All planets revolve around the Sun in the same direction and approximately in the same plane of the Sun's own rotation

Answer 30

True

Question 31

The motions of the system members define what shape?

Answer 31

a disk

Question 32

How old is the solar system?

Answer 32

4.5 billion years

Question 33

The solar system forming out of a rotating cloud of vapor and dust is known as what?

Answer 33

Solar Nebula

Question 34

planetesimals

Answer 34

small bodies that are considered the building blocks of planets

Question 35

protoplanets

Answer 35

larger objects that form when numerous planetesimals collide and clump together - "pre-planet" stage

Question 36

Which 2 planets control the distribution of asteroids through their gravity?

Answer 36

Jupiter and Saturn

Question 37

What is Earth mostly composed of?

Answer 37

Heavy elements (silicon, iron, oxygen)

Question 38

What are the Sun and stars composed of?

Answer 38

Light elements (hydrogen and helium)

Question 39

Seismic Waves

Answer 39

waves that spread through the interior of the Earth and form earthquakes and explosion sites (volcanoes)

Question 40

Layers of the planet in order

Answer 40

Crust, Mantle, Core, Inner Core

Question 41

Oceanic crust

Answer 41

Covers the majority of the Earth's surface and is composed of basalt

Question 42

Basalt

Answer 42

volcanic rocks

Question 43

Continental Crust

Answer 43

Covers only 45% of the Earth's surface and is composed of granite

Question 44

Mantle

Answer 44

the largest part of the Earth's core - 2900 kilometers deep

Question 45

True or false - The outer core is liquid and the inner core is "probably" solid

Answer 45

True

Question 46

The magnetic field is generated by...

Answer 46

moving material in Earth's liquid core

Question 47

Plate Tectonics

Answer 47

slow motions in the mantle move large segments of the crust - results in "drifting" of the continents and formations of mountains

Question 48

Rift zones

Answer 48

plates pulling apart from one another

Question 49

Subduction zone

Answer 49

2 plates come together, forcing one plate beneath another

Question 50

Faults

Answer 50

plates sliding parallel to each other -mountains

Question 51

Troposphere

Answer 51

where clouds form and airplanes fly

Question 52

Stratosphere

Answer 52

cold and free of clouds

Question 53

Ozone

Answer 53

protects the surface from some of the Sun's radiation

Question 54

Weather

Answer 54

circulation of the atmosphere

Question 55

Climate

Answer 55

the effects of the atmosphere that last through centuries

Question 56

Greenhouse Effect

Answer 56

gases in a planet's atmosphere trap heat from the sun, warming the planet's surface

Question 57

planets closest to the sun in order

Answer 57

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

Question 58

Motion of the Celestial Objects

Answer 58

primarily move in elliptical orbits around a larger gravitational body, like the Sun - due to the force of gravity