Download VOCAB astronomy File

ASTRONOMY VOCABULARY
1. SOLAR SYSTEM- a star (sun) and all the objects that orbit it
2. PLANET-an object that orbits the sun that is large enough for gravity to pull itself round
3. ORBIT- a path that an object takes during a revolution
4. TERRESTRIAL PLANET- an earth-like planet that has a rocky surface
5. ROTATION- One spin of a planet (a day and a night)
6. REVOLUTION- One trip around the sun
7. RETROGRADE- a clockwise spin if looking down on the north pole
8. PROGRADE- a counterclockwise spin if looking down on the north pole
9. MERCURY- 1st planet which is rocky and highly cratered
10. VENUS- 2nd planet which is rocky and extremely hot due to a thick CO2 atmosphere
11. MARS- 4th planet which is rocky and red from iron oxide
12. GASEOUS GIANT- a large planet made of an atmosphere of gas and a surface of liquid
13. JUPITER- 5th planet which is gasey and the largest of all
14. SATURN- 6th planet which is gasey and has a large set of rings
15. URANUS- 7th planet which is gasey and blue-green due to methane gas
16. NEPTUNE- 8th planet which is gasey and blue-green due to frozen methane gas
17. PLUTO- planetesimal who’s orbit is farther out than Neptune and who’s moon is more than half
its size
18. PLANETESIMAL- tiny planet that is not round enough to qualify as a true planet
19. COMET- dirty snowball with huge elliptical that orbits around the sun. Disintegrates as it
approaches the sun.
20. COMET NUCLEUS- the rock, ice, and frozen gas core of a comet
21. COMA- the evaporated gases and bits of dust that fling off a comet as it approaches the sun
22. TAIL – the coma that gets stretches out and always points away from the sun
23. OORT CLOUD-zone beyond Pluto that comets may come from
24. HALLEY’S COMET- period comet that comes back every 76 years
25. ASTEROID- large rock in space
26. ASTEROID BELT- zone between Mars and Jupiter that contains many space rocks
27. METEOROID-smaller rock in space
28. METEOR- a small space rock that is going through a planet’s atmosphere and making a glowing
streak due to friction
29. METEORITE- a small space rock that doesn’t completely disintegrate and actually lands on a
planet
30. STAR- a large ball of fusing gas that gives off tremendous radiant energy
31. ACCRETION- the process whereby gravity pulls together dust, rocks, and gases to make stars,
planets, asteroids, etc. Growing larger by adding chunks.
SUN
32. NEBULA- a large cloud of gas and dust in space
33. SOLAR NEBULA- the cloud of gas and dust that formed our solar system
34. CORONA- “crown” outer layer of sun, upper atmosphere
35. CHROMOSPHERE- the 2nd layer of the sun, the lower atmosphere
36. PHOTOSPHERE- the visible surface of the sun
37. CONVECTION ZONE- zone where hot gases rise and cool gases sink
38. RADIATIVE ZONE- dense zone of gamma rays, energy here for a million years
39. CORE- place where fusion occurs
40. FUSION- process of forcing 4 hydrogen atoms to fuse together into 1 helium
41. SOLAR FLARE- explosion from a sunspot that goes into space
42. PROMINENCE- Massive explosion from the sun that ejects ten billion tons of mass (protons) and
energy into space
43. CORONAL MASS EJECTION – CME Massive explosion from the sun that ejects ten billion tons of mass
(protons) and energy into space
44. CORONAL LOOP- gases held up in a magnetic loop—reach from sunspot to sunspot(doesn’t leave Sun)
45. SUNSPOT- dark region on sun where a solar flare will erupt
46. AURORA BOREALIS- “northern lights” caused by solar flares making our atmosphere gases glow
47. AURORA AUSTRALIS- “southern lights”
48. LIGHT YEAR- distance light travels in a year
49. SUNSPOT MINIMUM- time during the 11 yr cycle when there are few sunspots
50. SUNSPOT MAXIMUM- time during the 11 yr cycle when there are many sunspots
51. ACTUAL BRIGHTNESS-brightness of a star if you are right next to it
52. APPARENT BRIGHTNESS-brightness of a star as it appears from earth
STARS
53. Loner star- a star by itself (our sun is a loner)
54. Binary system- 2 stars orbiting each other
55. Star cluster-100’s or 1000’s of stars held together by gravity
56. Dark line spectrum analysis- method of finding star’s composition by comparing an element’s spectrum
with the star’s spectrum
57. Hertzsprung-Russell diagram- graphic that shows all the star types and how they change from living to
dying stars
58. Main sequence- “living” young stars in the HR diagram
59. Red dwarf- cool, dim star
60. Sun class- medium temperature, medium brightness star
61. Red giant- cool, bright star
62. Blue giant- hot, bright star
63. White dwarf- hot, dim star
64. Supernova- what super giants may turn into
65. Black hole- a very dense region in space that has gravity so large it can draw in light
GALAXIES
66. UNIVERSE- all things in existence
67. GALAXY- HUGE collection of stars (billions) held together by gravity
68. ELLIPTICAL GALAXY- old galaxy that is round or football shaped
69. SPIRAL GALAXY- medium aged galaxy with arms extending outwards from a central hub
70. IRREGULAR GALAXY- young galaxy who’s gravity hasn’t had time to pull it together into a circular
pattern yet
71. BIG BANG- theory of the beginning of the universe