| A | B |
|---|
| nuclear reaction | a reaction in which the nuclei of atoms change |
| thermonuclear fusion | a reaction in which the nuclei of atoms combine |
| fuse | combine |
| photosynthesis | the use of sunlight by plants to make food |
| satellite | a body that moves around a larger one in space |
| crater | a bowl-shaped hole |
| rotate | spin around an axis |
| rotation | spinning around an axis |
| axis | an imaginary line around which something spins |
| revolution | the motion of a body traveling around another body |
| revolve | move around another body |
| phases | changes we see in the moon's shape |
| crescent phase | a phase of the moon in which we see less than half of the moon's face |
| gibbous phase | a phase of the moon in which we see more than half of the moon's face |
| umbra | the dark part of a shadow |
| penumbra | the lighter shadow around an umbra |
| eclipse | what happens when one body in space blocks the sum's light from reaching another body |
| lunar eclipse | an eclipse of the moon |
| total solar eclipse | an eclipse of the sun in which the sun's entire face is darkened |
| partial solar eclipse | an eclipse of the sun in which only part of the sun's face is darkened |
