The stars in our sky twinkle in brightness and color because of _________.

The virgin galactic will soon _____.

Select all of the answers that apply. dark matter may be _____.

Kepler was the first to be credited for discovering that planets follow __________.

One-way streets have unique features including __________.

The center-of-gravity method is often used to locate__________.

For los angeles, during the autumnal equinox there are about _____ hours of daylight.

By examining the widths of the spectral lines we can find information about a star's _________.

During its red giant stage, the radius of the sun will be about __________.

During a solar eclipse, the _____ casts a small circular shadow on the ____.

Directly above the earth's equator lies the ______________ in the sky.