| A | B |
|---|
| scientific notation | a system for representing numbers in which a number is written as the product of a power of 10 and a number that is at least 1 but less than 10 |
| light year | distance light travels 1 light year=about 6 trillion or 5.9 trillion miles |
| diameter of a sphere | a line segment that passes through the center of a sphere and has endpoints on the sphere |
| rotation | a turn around a center point or axis |
| ellipse | a closed,oval, plane(flat) figure |
| astronomical unit | the average distance from the earth to the sun miles=93 million |
