22-2

Question 1

what is rotation?

Answer 1

spinning of Earth on its axis, takes 24 hours for one; what causes day/night
As Earth rotates east, sun appears to move west and in a regular pattern

Question 2

what is Earth’s axis?

Answer 2

imaginary line around which Earth spins. Greater inertia at equator, so bulges out and flattens poles

Question 3

what is revolution?

Answer 3

movement of an object around another object; orbit around some point in space

Question 4

what is Earth’s orbit like? Is the distance from Earth to Sun always the same or changing?

Answer 4

not circular, an ellipse, elongated closed curve, sun is offset from center so distance from Earth to sun is always changing; does not cause seasons

Question 5

what is perihelion and aphelion?

Answer 5

Perihelion: Earth is closest to sun on January 3
Aphelion: Earth is farthest to sun on July 4

Question 6

what is ecliptic?

Answer 6

apparent annual path of the sun against the backdrop of the celestial sphere

Question 7

what does Earth’s tilt cause?

Answer 7

seasonal changes

Question 8

what is the plane of the ecliptic?

Answer 8

the imaginary plane that connects earth’s orbit with celestial sphere

Question 9

what is celestial equator?

Answer 9

the projection of Earth’s equator onto the sky

Question 10

what are the effects of tilting?

Answer 10

1. seasons - summer: when hemisphere is tilted to sun winter: when tilted away
2. Sun’s radiations strikes hemisphere at less of an angle, energy bounces off

Question 11

what are solstices?

Answer 11

when sun reaches greatest distance north or south of equator.
Northern hemisphere: summer solstice on June 20/21, more daylight hours, most directly overhead. Winter on Dec. 21/22, shortest daylight hours

Question 12

what are equinoxes?

Answer 12

when sun is directly above the Earth’s equator, sun’s rays strike equator at highest angle; twice a year, daylight hours are equal, no tilt. Spring equinox: march 19/20, fall equinox: september 22/23

Question 13

what is precession?

Answer 13

Earth’s slow motion; slight cone-shaped movement of where Earth’s axis points

Question 14

what is a period of precession?

Answer 14

amount of time for the axis to complete one circle

Question 15

What is the motion of Earth in relation to the Sun and the galaxy?

Answer 15

Earth moves with the Sun as the solar system speeds toward Vega.
The Sun revolves around the Milky Way galaxy, and galaxies themselves are also in motion.

Question 16

what does revolution around Earth cause?

Answer 16

different phases of moons, moon rotates around its axis

Question 17

what is perigee and apogee?

Answer 17

when moon is closest to Earth, apogee farthest from Earth

Question 18

what happens to get phases of the moon?

Answer 18

moon shines by reflecting sunlight from surface, as Moon revolves around Earth you see different portions of it’s lighted side causing Moon’s appearance to change

Question 19

what is new moon?

Answer 19

when the moon is between Earth and sun, lighted half facing sun and dark facing Earth, new moon rises and sets with the sun

Question 20

what is waxing crescent?

Answer 20

after new moon, thin slice of lighted side becomes visible on right side

Question 21

what is first quarter?

Answer 21

half of the lighted side on right side, after waxing crescent

Question 22

what is waxing gibbous?

Answer 22

after first quarter, lighted side more and more visible on right side

Question 23

what is full moon?

Answer 23

when all of the moon’s surface we see is visible, half of moon that lights up is seen

Question 24

what is waning gibbous?

Answer 24

after full moon, lighted side more and more visible on left side

Question 25

what is third quarter?

Answer 25

when half of the lighted side can be seen on left side

Question 26

what is waning crescent?

Answer 26

small slice of the lighted side of the moon on the left side

Question 27

What is a synodic month?

Answer 27

The time it takes for the Moon to go through all its phases as seen from Earth — about 29.5 days.

Question 28

what is sidereal month?

Answer 28

time it takes the Moon to complete one full orbit around Earth (27.3 days), measured against the background stars, not the Sun, shorter than the 29.5-day phase cycle because Earth is also moving around the Sun

Question 29

Why do we always see the same side of the Moon from Earth?

Answer 29

The Moon spins once every 27.3 days (the same time it takes to orbit Earth) so we always see the same side. Each spot has about 2 weeks of daylight and of night

Question 30

why is there such high temperature on the day side of the moon and such low on the night side?

Answer 30

there is no atmosphere on the moon

Question 31

What was Sputnik 1 and why was it important?

Answer 31

first artificial satellite, launched by Soviet Union in 1957, began the space race, lead U.S. to start its own space program and land on the Moon

Question 32

what is a satellite? what is an natural and artificial satellite?

Answer 32

Satellite: any object that revolves around another object Natural satellite: moon, artificial satellites: man made satellites that orbit Earth

Question 33

what was saturn V? who took the first steps on the moon?

Answer 33

most powerful multistage rocket that made it possible to send spacecraft to the moon/solar system; Neil Armstrong took first steps on moon

Question 34

what is an eclipse? what would happen if the moon was lined up with Earth's orbit?

Answer 34

Moon blocks sunlight or enters Earth's shadow, rare because Moon's orbit is tilted. If lined up with Earth’s orbit, we’d have eclipses every new moon

Question 35

what is the umbra?

Answer 35

darkest part of Moon’s shadow where a total solar eclipse is seen. Only Sun’s outer atmosphere (a pearly glow) is visible

Question 36

what is the penumbra?

Answer 36

lighter shadow on Earth’s surface where a partial solar eclipse is seen, photos taken of curved edge of the moon moving over portion of the sun

Question 37

what is a lunar eclipse? Why is it more regularly seen if a solar eclipse happens more?

Answer 37

when earth is between the moon and sun, during a full moon. Moon moves into Earth’s shadow, starting with penumbra and then into umbra, casts curved shadow on Moon. More regularly seen because casts a bigger shadow and everyone on the night side of the Earth can see it, but only those in line with it can see it in solar eclipses

Question 38

what is a total lunar eclipse?

Answer 38

Moon fully in Earth’s umbra and goes dark. Sometimes, Earth’s atmosphere bends sunlight, making the Moon appear red

Question 39

what is a partial lunar eclipse?

Answer 39

part of the Moon enters Earth’s umbra and the rest stays in the penumbra, still lit by the Sun. Umbra's edge looks blurry and moves across the Moon for 2–3 hours

Question 40

what is total solar eclipse?

Answer 40

zero to two times a year, shadow cast by moon on Earth in the umbra is small portion so less likely seen