Easiest crossword puzzle

Across

1.     God in reverse star

4.     Closest orbit

5.     No canals

6.     Explores Saturn

9.     light

10.   Saturn's Earth like moon

12.   Winter star

15.   Virgin

16.   First manned spacecraft on the moon

17.   This planet has the blues

18.   SciFi writer

Down

1.     Blowed up real good

2.     Gas giant

3.     Mar's canyon -- Valles

6.     Nebulae

7.     Blue people live here

8.     Tip of Orion

11.   Seven sisters

13.   Ringed planet

14.   Mars valcanoe -- Olympus

15.   A planet for lovers only