Astronomy Crossword

When the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days.
The days when the night and day are equal.
Elliptical course of a celestial object around a star or planet.
An imaginary line about which a celestial object rotates.
Action of spinning about one's axis.
Action of going around one's orbit.
The first 4 planets in our solar system which are made out of rocks.
A theory that it was a single event, like an explosion, that had began the universe.
The force that attracts objects to its center.
The 4 outer planets in our solar system which are made up of gas.
A region of space having a gravitational field so intense that no matter, nor light, can escape.
The person who studies astronomy
The natural satellite of the planets in our solar system.
A cluster of stars, dust and gas held together by the force of gravity.
A luminous object mainly made of gas, like the sun.
Rocky objects that make the belt between Mars and Jupiter.