Earth Rotation
What causes day and night on Earth?
Earth's rotation on its axis.
It takes Earth about 365.25 days to complete one full revolution around this object.
The Sun
This term describes the Moon when it appears to be growing larger in light each night.
Waxing
This massive object sits at the center of our solar system and holds all the planets in orbit with its immense gravity.
Sun
How long does it take Earth to complete one full rotation relative to the Sun (one solar day)?
About 24 hours.
Combined with Earth's tilted axis, our planet's revolution causes this cyclical change in weather and daylight.
Seasons
When the Moon looks like a perfect half-circle, it is in this specific phase.
First/Third quarter
These are the four inner planets made of rock and metal, grouped together by their material composition.
Terrestrial planets
Because Earth rotates from West to East, the Sun, Moon, and stars always appear to rise in this direction.
East
We add an extra day to the calendar every four years (Leap Year) to make up for this fractional amount of a day left over from Earth's actual revolution time.
Quarter or .25
This word, which sounds like a shape, describes the Moon when it is more than half full but not quite a complete circle.
Gibbous
Located between Mars and Jupiter, this region is filled with millions of rocky remnants from the early solar system.
Asteroid Belt
This is the imaginary line running through the North and South Poles that Earth spins around.
Axis
This specific term refers to the two days a year when Earth's axis is tilted neither toward nor away from the sun, resulting in nearly equal day and night everywhere.
Equinox
This is the only phase where a solar eclipse can happen, because the Moon is positioned directly between the Earth and the Sun.
New Moon
Because of its thick atmosphere of carbon dioxide trapping heat, this planet is the hottest in our solar system, even though it isn't closest to the Sun.
Venus
Earth's axis isn't perfectly straight up and down; it is tilted at this specific angle.
23.5
Earth's orbital path around the Sun is not a perfect circle, but rather this oval-like shape.
Ellipse
It takes approximately this many days for the Moon to complete a full cycle of all its phases.
This outer planet spins completely on its side at a 90 degree angle.
Uranus