1. Space Vocabulary

2. Sphere A round object, like a globe. In space, a planet, moon or star.
Origin: 1250–1300; < LL sphēra,  L sphaera  globe < Gk sphaîra  ball; r. ME spere  < OF spere  < LL spēra,  var. of sphēra

4. Axis The line around which a body, or planet, rotates
Origin: 1540–50; < L axis  an axletree, axle, axis.

5. Ellipse In space, an orbit that is not flat but an elongated circle.
Origin: 1745–55; < F < L ellīpsis ellipsis; or by back formation from the pl. ellipses

7. Solstice
The two times a year (December and June) when the Earth’s axis points most towards or away from the sun. Longest and shortest days.
Origin: 1200–50; < ME < OF < L sōlstitium,  equiv. to sōl  sun + -stit-,  comb. form of stat-,  var. s. of sistere  to make stand ( see stand) + -ium -ium; see -ice)

8. Moon Phase
The step in the journey around the Earth that the moon takes; can be seen in 8 phases with different amounts of light and dark
Origin: 1805–15; (n.) back formation from phases

11. Waxing
In science, when the moon is growing brighter from right to left.
Wax “on”
Origin: bef. 900; ME waxen,  OE weaxan;  c. G wachsen;  akin to waist
—Synonyms 1.  extend, grow, lengthen, enlarge, dilate.

12. Waning
In science, when the surface of the moon is growing darker from right to left.
Origin: bef. 900; ME wanen  (v.), OE wanian  to lessen; c. MD, MHG wanen,  ON vana  to cause to wane, destroy

13. New Moon
When the moon is in the phase where the side facing the Earth is completely dark, no illumination.

14. First Quarter
The phase in the lunar cycle wherein the right half of the moon is illuminated
Origin: 1250–1300; (n.) ME < AF; OF quartier  < L quartārius,  equiv. to quart ( us ) fourth + -ārius -ary; (v.) ME quarteren,  deriv. of the n.

15. Third quarter
The phase of the moon when the left half is illuminated, opposite sides from 1st quarter

16. Solar eclipse
When the moon blocks light from the Sun from landing on the Earth
Origin: 1400–50; late ME < L sōlāris,  equiv. to sōl sun + -āris -ar1

17. Solar eclipse

18. Lunar eclipse
When the Earth gets in the way of the Sun’s light and casts a shadow on the moon
Origin: 1585–95; < L lūnāris  of the moon. See Luna

19. Lunar eclipse (last weekend)

20. Maria Dark spots on the surface of the moon
Caused by asteroids hitting the surface hard enough that lava seeped up and filled in the surface
Origin: 1680–90;  < L: sea

21. Equinox
Twice a year (March and September) when the Earth’s axis is halfway between the two extreme points, creating 12 hours of light and 12 hours of dark
equinox late 14c., from O.Fr. equinoxe , from M.L. equinoxium  "equality of night (and day)," from L. aequinoctium,  from aequus  "equal" + nox  (gen. noctis ) "night." The O.E. translation was efnniht . Related: Equinoctial

22. Rotation
An object that moves or spins on its axis.

23. Revolution One body going around another body
Moon revolves around Earth
Earth revolves around Sun
revolution late 14c., originally of celestial bodies, from O.Fr. revolution , from L.L. revolutionem  (nom. revolutio ) "a revolving," from L. revolutus , pp. of revolvere  "turn, roll back"