Solar System

5. the common center of mass around which two or more celestial bodies orbit
6. The fuse process where light atomic nuclear typically hydrogen combine under extreme heat and pressure
8. a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch
9. the gradual accumulation of matter, particles, or property, causing a body to increase in size or value through external addition

1. These planets are the four large outer planets in our solar system
2. the splitting of a heavy atomic nucleus
3. a dimensionless measure of how much a planet’s orbit deviates from a perfect circle
4. These planets are rocky, Earth-like worlds composed primarily of silicate rocks, metals, and solid surfaces
6. the distortion of a planet from a perfect sphere into an oblate spheroid, where the planet bulges at the equator and flattens at the poles
7. rapid accumulation of gas or solid debris under mutual gravity, forming small planets or giant planets