earth rotates on what?
how long is earth's journey around the sun?
how many hours does earth take to rotate?
what are earth's spheres?
what is a solstice?
what is an equinox?
what is atmosphere?
what is biosphere?
what is climate?
what is cryosphere?
what is direct light from the sun?
what is earth's journey around the sun called?
what is erosion?
what is geosphere?
what is hydrosphere?
what is the earth's crust?
what is the earth's inner core?
what is the earth's mantle?
what is the earth's outer core?
what is the tilt of the earth?