| A | B |
|---|
| orbit | the path one object takes around another object in space |
| tide | the rise and fall of the water level of the ocean near the shore that is caused by the pull of the gravity of the moon |
| lunar cycle | the process of the Moon changing shapes |
| solar system | made of the Sun and all objects that are bound to the sun by gravity |
| star | an object in space that makes its own heat and light |
| corona | makes up most of the Sun's atmosphere |
| sunspot | an area on the surface of the sun that appears darker than other areas |
| solar flare | a large explosion in the Sun's atmosphere |
| solar energy | energy from the Sun |
| wind | moving air |
| revolution | the time it takes for an object to travel completely around another object it orbits |
| day | the time during rotation when Earth faces the Sun, and it is lighted; this rotation gives the false appearance that the Sun travels from east to west across the sky |
| night | the time during its rotation when Earth faces away from the Sun, and it is dark; this rotation gives the false appearance that stars move across the sky |
| shadow | a dark area caused when an object blocks light falling on a surface |
