The Solar System Crossword ACROSS 4. Although not the closest to the sun, this planet is the hottest because of a thick atmosphere of carbon dioxide. 5. This object is no longer considered to be a planet. 6. Its two satellites are named Phobos and Deimos (Fear and Panic). 8. You were born on this planet, hopefully. 9. The closest planet to the sun, it orbits the sun once every 88 days. 11. This planet is more massive than all of the others combined. 12. This planet's axis is so tilted that it orbits the sun on its side. DOWN 1. Made mainly from ices and dust, these objects can form tails millions of kilometers long when they pass near the sun. 2. Named for the Roman god of the sea. 3. This object is at the center of the Solar System. 7. Chunks of rock, most of which are found between the orbits of Mars and Jupiter. 10. This planet possesses the Solar System's most impressive system of rings. From https://education.jlab.org