astronomy unit test Flashcards
When was the Big Bang Theory occurred?
What time was it called?
The Big Bang Theory occurred 10-20 billion years ago. This was called time zero.
Describe the universe at the time of the Big Bang
- All matter in the universe was closely packed together
- extremely high density and temperature
What evidence do we have of the Big Bang?
- The Red Shift of light coming from distant galaxies shows that they are moving away from us. So therefore the universe is expanding.
- Evidence that the universe is “glowing” from the initial “explosive” event
Definition of meteor
a meteoroid that burns up as it travels through Earth’s atmosphere
Definition of meteoroid
a small celestial object made of rock or metal moving around in space before it enters Earth’s atmosphere
Definition of meteorite
A meteor that survives Earth’s atmosphere and reaches the surface and could leave a huge crater.
Where is the asteroid belt?
Between Mars and Jupiter
boundary between inner planets and outer planets
period of day and night on Earth are cause by?
name 2
- the rotation of the Earth on its axis
2. whether the Earth is facing/tilted toward the sun or away from the sun
Important date of the four seasons
winter solstice: December 21
summer solstice: June 21
spring equinox: March 21
fall equinox: September 23
what happens on each of these days (spring/fall equinox) across the whole world?
every place on Earth has 12 hours of day and 12 hours of night
The seasons on Earth are caused by?
name 3
- the revolution of the Earth around the sun
- the tilt of the Earth
- whether a point on the Earth receives direct or indirect rays of light from the sun
what season is it when the Northern Hemisphere tilted toward the Sun?
describe the Sun’s rays
the season would be summer because since the northern hemisphere is tilted toward the Sun, the sun’s rays are direct, resulting in hot weather
what season is it when the Northern hemisphere is tilted away from the Sun? Describe the Sun’s rays
The season would be winter because the Northern hemisphere is tilted away from the sun, the sun’s rays would be indirect and it is weak, resulting in cool/cold weather.
what causes Spring and Fall? Describe the tilt of the Earth and the Sun’s rays.
when the Earth’s axis is tilted neither toward nor away from the sun and the sun’s rays are neither direct or indirect which causes spring and fall
What is an eclipse?
an eclipse occurs when one celestial body blocks the view of or light from another celestial body
what must occur in order for there to be a solar eclipse? (name 3)
- the moon blocks the sun’s rays from reaching the Earth
- when it’s a new moon
- when the moon passes between Earth and the Sun
how long would you have to wait to see a total eclipse twice, from the exact same location on Earth?
it would take 375 years to see a total solar eclipse twice from the same location on Earth
who studied venus?
Magellan
who studied mars?
viking