29.1 Flashcards
sphere
three-dimensional, round object whose surface is the same distance from the center in every direction
ellipse
elongated, closed curved with two foci; shaped of earths orbit around the sun.
Is earth a perfect sphere?
No, because of the diameter is longer than the height
What are some pieces of ancient observation to prove that earth is a sphere
- objects fall straight down.
- the shadow on the moon during a lunar eclipse
- different continents see different stars
What are two things that affect gravitational forces?
The masses of each object and the distance between them.
Which diameter is longer?
The equator
What does the magnetic field do for earth?
Protects us from harmful radiation from the sun
which magnetic pull is in the northern hemisphere
the south magnet pull
What degrees is earths axis tilted at
11.7 degrees
What is the flipping of the north magnetic pull and the south magnetic called?
The Magnetic Reversal
How often do magnetic reversals occur
every 200,000 years
When was the last magnetic reversals happened?
700,080 years ago.
What is a magnetosphere
Deflects harmful radiations from the sun,
How are the Auroras created?
When an electrically charged particles collide with atoms in the atmosphere and emit light.
what is the scientific name for the northern light
the Aurora borealis
What is the scientific name for the southern hemisphere
The Aurora Australis
When is earth closets to the sun?
Early January, about 147 million km
When is earth farthest from the sun?
Early July, about 152 million km away
