Kahn Academy Earth and Space Science Flashcards
(86 cards)
What two variables is Gravity Influenced by?
Mass and the distance between objects
What are Mar’s two moons?
Phobos (fear) and Deimos (dread)
Mars’ atmosphere
Thin atmosphere of carbon dioxide
What is the Oort Cloud?
Space at the very edge of the solar system that is filled with comets made of ice and dust.
How often does Halley’s Comet come near Earth?
Every 75 years
What is Jupiter’s atmosphere made of?
Hydrogen and Helium
How many moons does Jupiter have?
50
How was the Solar System formed?
By a huge cloud of gas and dust 4.6 billion years ago.
Common features of terrestrial planets
Thin atmospheres, solid surfaces, few or no moons, no rings.
Common features of Gas Giant planets
Thick atmospheres, no solid surfaces, many moons and rings
Natural Satellite
Naturally occurring body that orbits a planet.
How long does the moon take to orbit Earth?
27 days
How long does it take for the moon to orbit on it’s axis?
27 days (the same amount of time it takes for it to orbit Earth, hence, the same side of the moon is always facing us)
Waxing Moon
Phases when the moon is growing bigger.
Waning Moon
Phases when the moon is growing smaller
The 8 Moon Phases
New, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent
New Moon
When the lit side of the moon is facing completely away from Earth.
Lunar Eclipse
When the moon is covered by Earth’s shadow.
Why do lunar eclipses only occur during full moons?
It’s the only time in Earth’s orbit where the Earth is between the sun and moon.
Why isn’t there a lunar eclipse every full moon?
Because the moon’s orbit around Earth is tilted relative to Earth’s orbit around the sun.
This means the moon passes just above or below Earth’s shadow.
How old is Earth’s water?
4.6 billion years old
What percent of water on Earth is Ocean?
95%
Transpiration
Evaporation of water from plants- water is absorbed through plant roots and through transpiration, turns into water vapor and leaves directly through the leaves through tiny pores called stomata and return to the atmosphere.
What force drive evaporation and transpiration?
The sun’s energy