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38 Cards in this Set
- Front
- Back
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How old is the universe? |
13.7 billion years old |
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How old is the solar system? How old is Earth? |
4.6 billion years old and 4.5 billion years old |
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What is rotation? How often does Earth go through this? |
Earth spinning on its axis. Every 24 hours |
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What is revolution? How often does the Earth do this? |
Revolution is the Earth orbiting the sun. It creates our calendar year |
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On what does a star's motion depend? |
Your latitude |
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What is perihelion? |
Earth is closet to the Sun on Dec. 21 but is tilted away |
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What aphelion? |
Earth is farthest away from the Sun on June 21st but is tilted toward the Sun |
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How often does the moon change cycles? |
Approximately every 29 and a half days |
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What is prograde motion? |
Planets appear to move through fixed stars. In this motion they move toward the east |
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What is retrograde motion? |
Planets appear to move through fixed stars. In this motion they move backward, toward the west. |
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What is cosmology? |
The study of the overall structure of the universe |
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What is the universe? |
The sum total of all matter and energy |
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Light travels at a finite speed of |
3.0 x 10^5 km/s |
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How old is the universe? |
13.7 billion years old |
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What is the celestial sphere? |
The imaginary sphere on which objects in the sky appear to reside when observed from Earth |
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What is the ecliptic? |
The sun's apparent path among the constellations |
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What are circumpolar stars? |
Stars located near the North Pole |
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How do heavenly bodies move? |
They rise in the east and set in the west |
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What are the 8 phases of the moon? |
New moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent, back to new moon |
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What is cosmogony? |
A theory about one's place in the universe |
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Significant thing and time estimate for Ptolemy |
Geocentric model placed the planet in orbits called epicycles on orbits called deferents. 90 AD to 168 AD |
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Significant thing and time estimate for Newton |
Newtonian picture (Infinite, repeating structure, no center in the universe). 1642-1727 |
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Significant thing and time estimate for kepler |
Three laws of planetary motion. 1571-1630 |
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Significant thing and time estimate for brahe |
best naked eye observations 1546-1601 |
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Significant thing and time estimate for copernicus |
heliocentric model. 1473-1543 |
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Significant thing and time estimate for galileo |
phases of venus (Solidify copernican revolution) 1564-1642 |
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Significant thing and time estimate for Eratosthenes |
circumference of the earth 276 BC to 194 BC |
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Significant thing and time estimate for Pythagoras |
geocentric model and immutable heavens 570 BC to 495 BC |
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Kepler's first law |
The orbit of a planet around the sun is an ellipse with the sun at one focus |
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Kepler's second law |
A line drawn out from the planet to the sun sweeps out equal areas in equal times |
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Kepler's third law |
The size of the orbit determines the orbital period |
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Planet travels slower or faster near the sun? |
faster |
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What did ancient civilizations achieve in astronomy? |
Daily time keeping, tracking the seasons and calendars, monitoring lunar cycles |
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How is a solar eclipse caused? |
Happens on the new moon and is on one of the nodes or close to it |
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How is a lunar eclipse caused? |
Happens on the full moon and is on the node or near it |
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If the sun is blocking a sign? |
The person born during that time is that sign |
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Where in the sky is the sign that the Sun is blocking? |
Highest in the sky |
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How do the signs move? |
Counter-clockwise |
