Chapter 29 Flashcards
A round, three-dimensional object, the surface of which is the same distance from the center in all directions
sphere
An elongated, closed curve with two foci
ellipse
What are some facts that prove the earth is a sphere?
- objects fall straight towards the surface
- shadow on moon
- People on different parts of the earth see different stars
What are two factors that affect gravitational pull?
Mass and distance
Which diameter of earth is longer?
equator
What does the magnetic field protect earth from?
Harmful radiation
What magnetic pull is located in the northern hemisphere?
South magnetic pull
At which degree is earths axis tilted?
11.7 degrees
Can magnetic pulls flip flop?
Yes
What is that large scale movement where the magnetic pulls flip?
Magnetic reversal
How often do magnetic reversals happen?
every 200,000 years
When did the last magnetic reversal happen?
780,000 years ago
Within earth’s magnetic sphere, what deflects harmful radiation?
Magnetosphere
What are the scientific name of the northern lights and the southern lights?
Northern: aurora borealis
Southern: aurora australis
How are the Aurora’s created?
Electrically-charged particles from the sun collide with atoms in the atmosphere and emit light
What month is earth closest to the sun?
January
What month is the earth farthest from the sun?
July
An area 15 degrees wide in which the time is the same
time zone
The spinning of Earth on its axis
rotation
The motion of Earth in an elliptical orbit around the sun
revolution
The plane of Earth’s orbit around the the sun
ecliptic
Occurs when Earth’s rotational axis is tilted directly toward the sun or away from the sun
solstice
The place where Earth’s rotational axis is perpendicular to a line drawn from the center of the sun
equinox
Who devised a method of timekeeping around 3000 BC?
Babylonians
What was the symbol for degree taken from?
Babylonians symbol for the sun
How many degrees does the earth spin in one day?
360 degrees
How many hours does it take the earth to make one full rotation?
24
How many degrees does the earth spin in one hour?
15
What direction does the sun rise?
east
What direction does the sun set?
west
True or false. All time zones are the exact same size?
False, they are modified to fit around cities, states, and country borders, and other key sites
How many time zones are there in the world?
24
Which direction do you move to add hours to the time?
East
Which direction do you move to subtract hours from the time?
West
How many time zones are there in the US?
6
What are the names of the time zones?
Atlantic/Alaskan, Pacific, Mountain, Central, Eastern
What is a solar day?
Sun at noon one day and sun at noon the next day
What is a sidereal day?
Looking at a certain star when it comes up again the next day
What are the two main reasons for seasons?
Revolution and tilt of the axis
Which 2 seasons have a solstice?
Summer and winter
Which month is the summer solstice?
June(21)
Which month is the winter solstice?
December(21)
Which two seasons are equinoxes?
Spring and Fall
Which month is the spring equinox?
March (20/21)
Which month is the fall equinox?
September (22/23)
When is the longest day of the year?
June 21
When is the shortest day of the year?
December 21
When are the days almost 12 hours of day and 12 hours of night?
Spring and fall equinox (March 21/22) (September 22/23)
A rise or fall in the ocean surface
tide
The change in appearance of the moon as seen from earth
moon phase
Occurs when the moon moves directly between the sun and earth casts a shadow on earth
solar eclipse
Occurs when Earth passes between the Sun and the moon and casts a shadow on the moon
lunar eclipse
Dark colored, flat, lava-filled regions on the Moon’s surface
Maria
A layer of dusty lunar material produced by collisions between astroids
Regolith
How many days does it take the moon to revolve around earth?
27.3
A complete lunar phase cycle takes 29.5 day, what is it called?
Synodic month
Do we ever see the back side of the moon?
No
What causes a tide to rise or fall?
Gravitational pulls of the sun and moon
What is the rise of sea level called?
High tide
After the sea level rises how many hours does it take for the sea level to drop?
6
Which is farther from the Earth, the moon or the sun?
Sun
Does the moon or the sun cause a greater effect on Earth’s tides?
Moon
How are the sun, the moon, and the Earth aligned for a spring tide?
The sun the earth and the moon are in a straight line
How are the sun, the earth, and the moon aligned for a neap tide?
The moon sun and earth create a 90 degree angle
What does the phase of the moon you see depend on?
The position of the Moon, Earth, and sun relative to each other
When does a new moon occur?
When the moon is between the earth and the sun
How many phases of the moon are there?
What is the definition of waxing phases?
What is the definition of waning phases?
The ill
What are the moon phase names?
New moon, waxing crescent, 1st quarter, waxing gibbous, full, waning gibbous, 3rd quarter, waning crescent
Where is the word month derived from?
German word meaning moon
How is the earth, sun, and moon aligned during a solar eclipse?
moon is between earth and sun
What is an umbra?
Darkest shadow from the moon that hits the earth
What is a penumbra?
Partial eclipse
How is the earth, moon, and sun aligned during a lunar eclipse?
The earth is between the sun and the moon
How are the depressions on the moon formed?
Meteors, asteroids, and comets
Are there mountains on the moon?
Yes
Which side of the moon is thicker?
Dark side (side earth doesn’t see)
Is the mantle of the moon solid or liquid?
solid
What did the Clementine Spacecraft do? (2 things)
Confirmed the thickness of the crust
What did the Lunar Prospector do? (3 things)
Surface photos of moon, confirmed it has a small, iron-rich core, supports the presence of water-ice on the moon
What is the Giant Impact Theory?
Mars size object hit earth sending debris into orbit which condensed and created a large sized mass (the moon)
