Ch 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
Is it Earth a perfect sphere?
No, the diameter around the Equator is longer than the diameter from Pole to Pole
What are some ancient observations that proves Earth is a sphere?
Any object that falls, falls straight down, the Earth’s shadow on the Moon during the Lunar Eclipse is curved, and people in different parts of the Earth see different stars above their horizons
What are two factors that affect gravitational strength?
Mass of object and Distance between them
Which one of Earth’s diameter is longer, pole to pole, or Equator?
Equator
What does the magnetic field protect Earth from?
Harmful Radiation from the Sun
Which hemisphere is the South Magnetic Pole located in?
The Northern Hemisphere
At what degrees, does Earth’s axis tilt?
11.7 Degrees
Can the Magnetic Poles change?
Yes
What is the name of the large-scale movement, where the magnetic poles switch?
Magnetic Reversals
How often do Magnetic Reversals occur?
Every 200,000 Years
Which part of Earth’s Magnetic Field, deflects harmful radiation from the Sun
Magnetosphere
What are the two scientific names for the Southern Lights and Northern Lights?
Aurora Borealis (Northern Lights) and Aurora Australis (Southern Lights)
How are the Auroras created?
Electrically charged particles in the Sun collide with atoms in the atmosphere and emit light
When is Earth closest to the Sun?
Early January- 147 Million km
When is Earth farthest to the Sun?
Early July- 152 Million km
An area 15 degrees wide in which the time is the same
Time Zone
The spinning of Earth on its axis, an imaginary line drawn from Earth’s North Pole to its South Pole
Rotation
The motion of Earth in an elliptical orbit around the Sun
Revolution
The plane of Earth’s orbit around the Sun
Ecliptic
Occurrence when Earth’s rotational axis is tilted directly toward the Sun or away from the Sun
Solstice
Occurrence when 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 B.C?
Babylonians
What was the symbol for degree taken from?
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 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 United States?
6 (Atlantic/Alaskan)
What are the names of the time zones in the United States?
Atlantic/Alaskan, Hawaiian, Mountain, Central, and Eastern Time
What is a solar day?
The movement of the Sun from one noon one day until one noon the next day
What is a sidereal day?
Looking at a star position until it comes back the next time
What are the two main reasons for seasons?
Revolution and Tilt of the Axis
Which two seasons have a solstice?
Winter and Summer
Which month is the summer solstice?
June 21
Which month is the winter solstice?
December 21
Which two seasons are equinoxes?
Fall/Autumn and Spring
Which month is the spring equinox?
March 20 or 21
Which month is the fall equinox?
September 22 or 23
When is the longest day of the year?
Summer Solstice (June 21)
When is the shortest day of the year?
Winter Solstice (December 21)
When are the days almost 12 hours of day and 12 hours of night?
Equinoxes (March 21 or 20) (September 22 or 23)
A rise or fall in the ocean surface
Tide
Reflects the change om appearance of the Moon as seen from Earth
Moon Phase
Occurrence when the Moon moves directly between the Sun and Earth and casts a shadow on Earth
Solar Eclipse
Occurrence when Earth passes between the Sun and the Moon and casts a shadow on the Moon
Lunar Eclipse
The dark-colored, flat, lava-filled regions on the Moon’s surface
Maria
A layer of dusty material produced by collisions between asteroids and comets and the Moon
Regolith
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 this called?
Synodic Month
Do we ever see the back side of the moon?
No, you only see one side
What causes a tide to rise or fall?
Gravitational pull by the Sun and Moon
What is the rise of sea level called?
High Tides
After the sea level rises how many hours does it take for the sea level drop?
6 Hours
Which is farther from Earth, the sun or the moon?
Sun
Does the moon or the sun cause a greater effect on Earth’s tides?
Moon
How are the sun. the earth, and the moon aligned for a spring tide?
They are in a straight line
How are the sun, the earth, and the moon aligned for a neap tide?
A 90 Degree Angle
What does the phase of the moon you see depend on?
Positions of the Moon, Earth, and Sun
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
What is the definition of waxing phases?
The illuminated portion of the Moon we see appears larger each night
What is the definition of waning phases?
The illuminated portion of the Moon that we see begins to appear smaller
What are the moon phases name?
New Moon, Waxing Crescent, 1st Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, 3rd Quarter, Waning Crescent
Where is the word month derived from? (root word)
Moon (Same Root Word)
How is the earth, moon, and the sun aligned during a solar eclipse?
The Moon is in between the Sun and Earth. Sun, Moon, Earth.
What is an umbra?
The darkest portion of the Moon’s shadow (Total Solar Eclipse)
What is a penumbra?
The lightest portion of the Moon’s shadow (Partial Solar Eclipse)
How is the earth, moon, and sun aligned during a lunar eclipse?
Moon, Earth, Sun. The Earth between the Sun and Moon
How are depressions on the moon formed?
Asteroids, Meteorites, and Comets strike the surfaces of planets and their satellite
Are there mountains on the moon?
Yes
Which side of the moon is thicker?
Far Side Crust/ Dark Side/ Back Side
Is the mantle of the moon a solid or a liquid?
Solid
What did the Clementine spacecraft do? (2 things)
Confirmed the thickness of the Moon and provided information on the mineral content of the Moon
What did the Lunar Prospector do? (3 things)
Took photographs of Moon’s surface, confirmed that the Moon has a small, iron-rich core, and collected evidence that supports the presence of water-ice on the Moon
What is the Giant Impact Theory?
The theory that a Mar-sized object collided with Earth, sending debris out into orbit, he debris condensed forming a large mass, the Moon
