Chapter 29 Flashcards
What is a sphere ?
A round, three - dimensional object, the surface of which is the same distance from the center in all directions.
What is a ellipse ?
Is an elongated, closed two foci
How can you tell that the Earth is a sphere ?
- People in different places see different stars
- Earth’s shadow on the moon during lunar eclipse is always curved
- Objects fall straight down to the surface as if they are falling toward the center of a sphere
What are two factors that affect the gravitational pull ?
Mass and distance of an object
What is the longest distance of Earth ? Pole to Pole or the Equator ?
26 miles
What does the magnetic field protect Earth from ?
Harmful Solar Radiation
Which magnetic pole is located in the Northern Hemisphere ?
South Magnetic Pole
Which magnetic pole is located in the Southern Hemisphere ?
Northern Hemisphere
At what degrees is Earth’s axis tilted ?
11.7 degrees
Can magnetic poles flip - flop ?
Yes
What are the large - scale movements called when the magnetic poles flip ?
Magnetic Reversals
How often do magnetic reversals occur ?
200,000 years
When did the last magnetic reversal happen ?
780,000 years ago
Within Earth’s magnetic field what reflects solar radiation ?
Magnetosphere
What are the scientific names for the Northern and Southern lights ?
Aurora Borealis and the Aurora Australis
How are the auroras created ?
Electrically - charged particles collide with atoms in the atmosphere and emit light
Which month is Earth closest to the sun ?
January
When is the Earth the farthest away from the sun ?
July
What is a time zone ?
An area 15 degrees wide in which the time is the same
What is a rotation ?
The spinning of Earth on its axis
What is a revolution ?
The motion of Earth in an elliptical orbit around the sun
What is the ecliptic ?
The plane of Earth’s orbit around the Sun
What is a solstice ?
Occurs when Earth’s rotational axis is tilted directly toward the Sun or away from the Sun
What is an equinox ?
When Earth’s rotational axis is perpendicular to a line drawn from the center of Earth to the center of the Sun
Who devised a method of timekeeping around 3000 B.C. ?
The Babylonians
What was the symbol for degree taken from ?
The symbol for degrees was taken from the Babylonian 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 hours
How many degrees does the Earth spin in one hour ?
15 degrees
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 all modified to fit around cities,states, and country borders, and other key sites.
How many time zones are there in the world ?
24 zones
How many time zones are there in the United States ?
6 zones
What are the names of the time zones ?
Pacific Time, Mediterranean Time, Atlantic/Alaskan Timezone, Central Timezone, Eastern Timezone, and Hawaiian Timezone
Which direction do you move to add hours to the time ?
East
Which direction do you move to subtract hours from the time ?
West
What is a solar day ?
The apparent movement of the Sun from noon one day until noon the next day
What is a sidereal day ?
When you see a star one day and see that exact same star the next day
What are the two main reasons for seasons ?
Due to the tilt of the axis and the Revolution
Which 2 seasons have a solstice ?
Winter and Summer
Which month is the summer solstice ?
June 21st
Which month is the winter solstice ?
December 21st
Which two season are equinoxes ?
Spring and Fall
Which month is the spring equinox ?
March
Which month is the fall equinox ?
September 22nd or 23rd
When is the longest day of the year ?
June 21st
When is the shortest day of the year ?
December 21st
When are the days almost 12 hours of day and 12 hours of night ?
March 21st or 22nd and September 22nd or 23rd
What are tides ?
A rise of fall in the ocean surface
What is a solar eclipse ?
When the Moon moves directly between the Sun and Earth and casts a shadow on the Earth
What is a lunar eclipse ?
When Earth passes between the Sun and the Moon and casts a shadow on the Moon
What is Maria ?
The dark - colored, flat, lave - filled regions on the Moon’s surface
What is a Regolith ?
A layer of dusty lunar material produced by collisions between asteroids and comets and the Moon
What is a moon phase ?
The change in appearance of the Moon as seen from Earth
How many days does it take the moon to revolve around Earth ?
27.3 days
A complete lunar phase cycle takes 29.5 days, what is the called ?
Also called a synodic month
Do we ever see the back side of the moon ?
No
What causes a tide to rise or fall ?
The gravitational pulls of the Sun and the 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 ?
Six hours
Which is father from Earth, the sun or the moon ?
The Sun
Does the moon or the sun cause a greater effect on Earth’s tides ?
The Moon
How are the sun, the earth, and the moon 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 ?
In a 90 degree angle
What does the phase of the moon you see depend on ?
Depends on the positions of the Moon, Earth, and the Sun relative to one 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 ?
Eight phases
What is the definition of waxing phases ?
The illuminated portion that we see appears larger each night
What is the definition of waning phases ?
The illuminated portion
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 ?
Derived from the same root word as Moon
How is the earth moon, and sun aligned during a solar eclipse ?
The moon is in between the sin and the Earth
Sun, Moon, Earth
What is an umbra ?
The darkest portion of the Moon’s shadow
What is a penumbra ?
A partial eclipse
How is the earth, moon, and sun aligned during a lunar eclipse ?
When the Earth is between the Sun and the Moon
Sun, Earth Moon
How are the depressions on the moon formed ?
Meteors, Comets, and Asteroids crash into the moon causing depressions and craters on the moon to form
Are there mountains on the moon ?
Yes
Which side of the moon is thicker ?
The one away from us
The Dark Side of the Moon
Is the mantle of the moon a solid or a liquid ?
What did the Clementine spacecraft do ?
Info on the mineral content of the moon rocks and the thickness of the crust
What did the Lunar Prospector do ?
Took photographs of the surface of the moon and confirmed that the Moon has a small iron - rich core
Collected presence of the ice/water on the Moon
What is the Giant Impact Theory ?
The Moon formed about 4.6 billion years ago when a Mars - sized object collided with Earth
