astronomy pt. 2

Question 1

what is the difference between the earth’s rotation and revolution?

Answer 1

rotation: produces day and night
revolution: one year (365.24 days)

Question 2

how fast does the earth move around the sun?

Answer 2

67,000 mph

Question 3

when is earth closest to the sun?

Answer 3

around january 2 (147 million km)

Question 4

when is earth farthest from the sun?

Answer 4

around july 4 (152 million km)

Question 5

how do we know that the earth revolves around the sun?

Answer 5

parallax

Question 6

what is parallax?

Answer 6

the apparent shift in position of a nearby star in relation to distant stars

Question 7

what are seasons caused by?

3 things

Answer 7

• earths revolution
• earths tilt
• earths axis is always pointed toward polaris
  - parallelism of the axis

Question 8

what degree is earth’s tilt?

Answer 8

23.5°

Question 9

if the earth didn’t revolve and was not tilted, what season would be at each location all year long?

• equator
• poles
• erie

Answer 9

equator: always summer
poles: always winter
erie: always “sprall”

Question 10

when is the summer solstice? where are the suns direct rays?

Answer 10

around july 21st

tropic of cancer (23.5° N)

Question 11

when is the winter solstice?

where are the suns direct rays?

Answer 11

around december 21st

tropic of capricorn (23.5° S)

Question 12

when is the spring/fall equinox?

where are the suns direct rays?

Answer 12

around march 21st & september 21st

the sun is directly overhead at the equator

Question 13

how many hours of daylight is there in each season?

Answer 13

winter- 8 hours
summer- 15 hours
spring/fall- 12 hours

Question 14

what is precession?

Answer 14

the movement of the earth’s axis

Question 15

how long does it take for the earth to “wobble” one full cycle?

Answer 15

26,000 years

Question 16

what is zenith?

Answer 16

when the sun is directly overhead

Question 17

what controls the tropics?

Answer 17

the earth’s tilt

Question 18

where does the sun rise and set in the winter/fall?

Answer 18

rises- SE

sets- SW

Question 19

where does the sun rise and set in the spring/summer?

Answer 19

rises- NE

sets- NW

Question 20

when does the sun rise and set exactly in the east and west?

Answer 20

during the equinoxes

Question 21

what is the celestial equator? how do you calculate it?

Answer 21

the projection of the earth’s equator into space

subtract the current latitude by 90°

Question 22

what is erie’s latitude?

Answer 22

approximately 42° N

Question 23

what is the ecliptic?

Answer 23

the path that the sun travels in the sky

Question 24

what is the waxing moon phase?

waning?

Answer 24

waxing- revolving toward full

waning- revolving toward new

Question 25

how long does it take the moon to revolve around the earth?

Answer 25

29 days

Question 26

what is the moon rise and set high point?

Answer 26

rise: -6 hours
set: +6 hours

Question 27

what are the oldest and youngest rocks on the moon? how old are they?

Answer 27

oldest- lunar highlands 4 billion years

youngest- maria 3.5 billon years

Question 28

where is the international dateline?

Answer 28

180° meridian

Question 29

what causes tides on earth?

2 things

Answer 29

• the earths rotation

- the moons gravity

Question 30

what moon phase is required for a solar eclipse? lunar?

Answer 30

solar- new moon

lunar- full moon

Question 31

what objects orbit the sun?

Answer 31

• planets
• moons
• asteroids
• comets

Question 32

what is a proto-planetary disc?

Answer 32

cloud of gas and dust

Question 33

how is a solar system formed?

Answer 33

• proto-planetary disc
• gravity pulls particles together
• sun forms-fusion of hydrogen and helium
• planets form from remaining material through accretion

Question 34

what are the inner planets?

Answer 34

• mercury
• venus
• earth
• mars

Question 35

what is the asteroid belt?

Answer 35

rocks and dust between mars and jupiter

Question 36

what are the outer planets?

Answer 36

• jupiter
• saturn
• uranus
• neptune

Question 37

what is the kuiper belt?

Answer 37

belt of debris at the edge of the solar system

Question 38

what is Olympus Mons?

Answer 38

the volcano on mars that went extinct

Question 39

what is Valles Marineris?

Answer 39

the huge canyon on mars

Question 40

why is pluto no longer considered a planet?

2 reasons

Answer 40

• it is very small

- the orbit is very different from the other planets that orbit the sun

Question 41

what holds planets in their orbits?

Answer 41

the suns gravity