Four solar system moons (Europa ,IO, Enceladus, Titan) Crossword

This printable crossword puzzle on the topic of Astronomy & Space has 10 clues. Answers range from 4 to 13 letters long. This crossword is also available to download as a Microsoft Word document or a PDF.

what does Europa have a high degree of?
what is IO moon's most distinctive feature?
What type of moon is Europa and IO?
What is Enceladus and Titan orbit center?
Titan is bigger than what planet?
how many types of surface features does Enceladus have?
what moon is one billion years old?
what moon has standing bodies of liquid on its surface (rivers, lakes, seas)?
which moon is the only moon is the solar system with a dense atmosphere?
Europa has an icy crust and that gives it what?