Order of the universe Crossword

This printable crossword puzzle on the topic of Astronomy & Space has 12 clues. Answers range from 4 to 21 letters long. This crossword is also available to download as a Microsoft Word document or a PDF.

A cloud of gas and dust
A system of stars held together by gravitational attraction
A natural satellite orbiting around a planet
Rock like objects between jupiter and mars
When 2 hydrogens form into a helium
A disk that is made of gas and dust and forms around a newly born star
Explains how solar system are formed from clouds gas and dust
A large body of matter thought to be developing into a planet also in orbit around a sun/star
a contracting mass of gas that represents an early stage in the formation of a star
the force that attracts a body toward another physical body
an instance of one moving object striking violently against another
a spherical shell of cometary bodies believed to surround the sun