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150 Cards in this Set
- Front
- Back
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1. What is the distance of Neptune from the Sun?
What is the diameter of Neptune? |
30 AU (4.5 billion km)
49,532 km (equatorial) |
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2. What is the density of Neptune?
What does this mean about the interior? |
1.7 g/cm^3
Higher than the other giant planets Little more rock in interior |
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3. What is the orbital period of Neptune?
What is the rotation period? What is the axial tilt? |
One year = 165 Earth days
One day = 16 hours (contributes to oblate shape) 29 degrees (has seasons) |
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4. How does Neptune interact with Uranus?
What is special about Neptune |
Orbit of Uranus is not as is should be in accordance w/ Newton's laws
Neptune must perturb Uranus' orbit Neptune was the first planet predicted rather than observed *predicted it b/c of Uranus' weird orbit |
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5. How strong is Neptune's magnetic field?
What is weird about its magnetic field? |
Less than half as strong as Earth's
Weird like Uranus' -tipped 47 degrees from rotational axis -offset 55% from center of planet |
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6. What produces the deep blue color of Uranus?
What are the dark spots seen on Neptune? |
Small amounts of methane gas that absorbs the red light from sunlight
(like Uranus) Methane clouds |
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7. What is the composition of Neptune's atmosphere?
How does it compare to Uranus' atmosphere? |
H (74%), He (25%), and methane (1-2%)
There are better banding than on Uranus Warmer than Uranus (should be cold though b/c further away) *source of internal heating is unknown |
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8. What are two characteristics of Neptune's atmosphere?
Does Neptune have winds? |
1. Latitudinal banding
2. Belt-zone circulation (like on other giant planets) YES!- very fast (1200 mph) |
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9. What is the Great Dark Spot of Neptune?
How many are there? |
Giant storm system
Dark spot 1: periodically disappears Dark spot 2: toward higher southern latitudes |
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10. How big is Dark Spot 1?
How fast does it rotate around Neptune? How does it appear to have been created? |
About size of Earth
Every 16 days Convecting gas rising from the interior |
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11. What is the color of Neptune's rings?
What is their composition? How does one ring appear? |
Very Dark (like Uranus and Jupiter)
Unknown composition Twisted |
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12. Are there any moons associated with Neptune's rings?
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6 minor moons
Two are known to shepherd the inner sharp ring |
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13. What is the interior of Neptune like?
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1. Similar to Uranus (slightly greater proportion of rock)
2. H-rich atmosphere (molecular H) gives way internally to slushy ice and rocky mantle overlying a rocky core |
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14. How big is Triton?
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2,710 km across
Bigger than Pluto |
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15. What is Triton?
When was it discovered? |
Neptune's seventh and largest satellite
Same time as Neptune |
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16. What is special about Triton's orbit?
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It is retrograde
It's the only large moon to orbit "backward" |
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17. Where did Triton form?
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Not from the primordial Solar Nebula
Formed elsewhere (perhaps in Kuiper belt) and later captured by Pluto Has similarities to Pluto (both Kuiper belt objects) |
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18. What is the blue tinge on Triton?
What is the pink tinge? |
Nitrogen frost
Methane ice |
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19. What is the surface of Triton like?
Five points |
1. Low crater density
2. Varied surface w/ active ice volcanoes 3. Prominent polar caps (ice caps on top of ice) 4. Network of ridges 5. Odd pitted surface like cantaloupe |
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20. What is Triton's density?
What does this suggest about it's composition? |
2.0 g/cm^3 (higher than other icy moons)
Only about 25% water ice Remainder is rocky material and other minor ices (N, methane, and CO2 ice) |
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21. What is Triton's atmosphere made of?
How is it? |
Mostly N w/ small amount of methane
Very tenuous Thin haze that extends up 5-10 km |
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22. What is the surface temperature of Triton?
Why is it so cold? What happens at this temperature? |
34.5 K (-391 F)
-as cold as Pluto Due in part to high albedo Methane, N, and CO2 all freeze solid |
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23. What is the southern hemisphere of Triton like?
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Almost entirely covered with "ice cap" of frozen nitrogen and methane
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24. What do the ice volcanoes on Triton erupt?
How are the eruptions? What drives the eruptions? |
Liquid nitrogen plus dust and/or methane compounds
Geyser like eruptions Seasonal heating from Sun (not internal heating!) |
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25. How far is Pluto from the Sun?
What is its diameter? What is its density? |
39.5 AU
2,274 Km 2.06 g/cm^3 (70-80% rock and 20-30% ices) |
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26. How long is one Pluto year?
How is Pluto's orbit? What does this mean? |
248 Earth years
Highly Eccentric and retrograde rotation At times it's closer to the Sun than Neptune |
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27. How long is one Pluto day?
What is Pluto's axial tilt? How is the plane of Pluto aligned? |
6.4 Earth days
118 degrees Equator is at almost right angles to the plane of tis orbit (like Uranus) |
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28. What is Pluto's surface composition?
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Unknown but probably mostly water ice and methane ice
Similar to Neptune's moon Triton |
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29. What are the brighter areas of the surface covered with?
What is the composition of the darker areas? What are the orange areas? |
Covered with ices of nitrogen with smaller amounts of (solid) methane, ethane, and carbon monoxide
Unknown but may be due to C-rich material or photochemical reactions driven by cosmic rays Probably hydrocarbons |
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30. How is Pluto's atmosphere?
What has been detected? When may the atmosphere only exist? |
Little is known about it
Nitrogen, methane, and carbon monoxide detected but very tenuous May exist as gas only when Pluto is near its perihelion *majority of long, atmospheric gases are frozen |
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31. What is Charon?
How big is it? Why is it unusual? |
Pluto's only known satellite
1172 Km It's the largest moon with respect to its primary planet in the solar system |
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32. What is the proposed origin of Pluto?
Why is this thought? |
Like Triton, innermost part of Kuiper belt
It has thousands of similar Pluto sized icy bodies beyond the orbit of Pluto |
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33. What is the proposed origin of Charon?
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Unclear
Possibly captured by Pluto or coformation? |
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34. What are comets?
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Icy bodies that originated in the outer solar system (beyond Pluto)
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35. What happens if they get within about 4 AU of the Sun?
What does this produce? |
Begin to sublimate
(ice turns to gas) A comet |
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36. What is the orbit of comets like?
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Long-period comets
-hundreds of thousands or even million of years to orbit Sun Short-period comets -periods less than 200 years |
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37. How far away are long-period comets at apehlion?
What does this do to their orbit? |
50,000 AU
Highly eccentric orbits and at all inclinations to ecliptic |
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38. What is the nucleus of a comet composed of?
What is the coma? |
Ice and gas with some dust and other solids
Weakly held "atmosphere" -formed as nucleus sublimates |
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39. What is the coma made up of?
What surrounds the coma? What produces this? |
Water, carbon dioxide, and other gases
Huge (millions of km in diameter), tenuous envelope of H Produced from disrupted water molecules |
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40. What are the two tails of the comet?
How are they produced? Where do they point? |
Ion (gas) tail and Dust tail
Sunlight and solar winds produce the two tails Point away from sun |
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41. What makes up the Ion or Gas tail?
How is it? How long is it? |
Ions swept directly aways from Sun by solar winds
Straight and relatively narrow Up to 100 million km long |
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42. What is the dust tail?
How is it? What eventually happens to these particles? |
Due to solid particles driven off the coma
Wide, diffuse, usually curved Orbit Sun |
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43. Where does the Kuiper belt lie?
What is it the source of? |
Beyond Neptune (30-100 AU)
Short-period comets |
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44. What is the Oort Cloud?
What is in the Oort Cloud? |
"Spherical" cloud of radius 50,000 AU centered on the Sun
Long-period comets (trillions of comets) |
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45. When was Halley's Comet's most recent perihelion passage?
How is it's orbits? How long is its orbital period? When will it return to the inner solar system |
1986
Retrograde and inclined 18 degrees to ecliptic (highly eccentric) 76 years 2061 |
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46. Where is the main asteroid belt located?
How far is it from the Sun? |
Between Mars and Jupiter
2-4 AU Bulk of known asteroids are found between Mars and Jupiter but some have more irregular orbits (including Earth-crossing) |
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47. How is the main asteroid belt divided?
What are Kirkwood gaps? |
Into subgroups named after the main asteroid in the group
Relatively empty regions between the main concentrations of asteroids in the Main Belt |
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48. How many asteroids have been discovered?
About how many of the asteroids larger than 100 km in diameter are known? |
Millions
99% |
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49. What is the largest known asteroids?
How big is it? About how much of the mass of all the asteroids combined does it contain? |
1 Ceres
933 km in diameter 25% |
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50. What are the next three largest asteroids?
How big are all other known asteroids? |
Pallas, Vesta, and Hygiea
(400 to 525 km in diameter) Less than 340 km across |
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51. What are some general properties of asteroids?
Four things |
1. Low eccentricities
2. Variable albedos (most less than 0.2) 3. Highly cratered, old surfaces 4. Asymmetric shapes |
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52. Where are metallic and stony asteroids found?
Where are less differentiated (mixed metal and stone) asteroids found? |
Closer to the Sun
Found further out |
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53. How are asteroids classified?
What are the three types of compositional asteroids? |
According to spectra (chemical composition) and albedo
C-type, S-type, and M-type |
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54. What are C-type asteroids?
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1. Extremely dark (albedo 0.03)
2. C-rich 3. Includes more than 75% of known asteroids |
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55. What are S-type asteroids?
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1. Relatively bright (albedo of 0.10)
2. Metallic nickel-iron mixed with iron- and magnesium-silicates 3. Silicate rich (hence S) 4. 17% |
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56. What are M-type asteroids?
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1. Bright (albedo .10-.18)
2. Pure nickel-iron (hence M) 3. Most of the rest |
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57. What type of asteroid is Gaspra?
Where does it orbit? How big is it? |
S-type asteroid
Orbits the Sun near the inner edge of the main asteroid belt 19x12x11 km |
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58. What is special about Gaspra?
When was it encountered and by what? |
First of only four asteroids that have been observed close-up
1991 by Galileo spacecraft on its way to Jupiter |
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59. How is Gaspra's surface?
How old do we estimate it to be? |
Covered with impact craters
(basalt composition) About 200 million years old |
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60. What type of asteroid is Ida?
How big is it? When was it encountered? |
C-type asteroid
58x23 km (bigger) 1993 by Galileo spacecraft on its way to Jupiter |
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61. What does Ida have that is unique?
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A satellite (Dactyl)
It orbits Ida at approx 90 km Dactyl is surprisingly round for such a small body |
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62. What type of asteroid is Eros?
What is important about Eros? |
S-type asteroid
Landed on Eros -NEAR-Shoemaker landed on Eros in 2001 |
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63. How is the surface of Eros?
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Highly cratered ancient surface
Rocks less than a meter in dimension are scattered on the surface Spectrometer determine surface composition after landing |
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64. What are NEA's?
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Near-Earth Asteroids
Ones that closely approach or cross (Earth-crossing asteroids) the Earth's orbit |
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65. About how many NEA's do we know of?
What important Earth events have been linked to asteroids? |
Probably only <10% of them
Many mass extinctions have been linked to asteroid impacts |
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66. How many NEA's pass close to Earth every 10 years?
How big are most NEA's? What can an asteroid this size do? |
>40 (some are closer than moon)
<1 km across (one is 100 km across) Has enough energy to wipe out many cities or small countries |
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67. What was the closest asteroid to Earth since the 12th century?
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4179 Toutatis (4.6 km across)
On Sept 27, 2004 |
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68. What are PHA's?
What is the criteria to be a PHA? |
Potentially Hazardous Asteroid
1. Orbit w/in 0.05 AU's of Earth 2. Diameter >150 km |
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69. What is the origin of asteroids?
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Planetisemals that never accreted into a planet due to proximity to Jupiter
Compositional differences now suggest they could never have been a single planet that was broken apart Alternative theory - always been lots of rumble that never made planet |
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70. What is the main source of meteorites?
What are meteoroids? What are meteors? What are meteorites? |
Asteroid belt
Rockly/metallic bodies w/ Earth-crossing orbits "Shooting Stars"; meteoroids that glow as they heat up through Earth's atmosphere Meteoroid found on Earth's surface |
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71. What is the solar nebula?
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A spinning disk of fine solid grains (dust) and gas from which all planets and our Sun formed
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72. What do nearby star-forming regions display?
What are these around? What are they analogous to? |
Protoplanetary discs (proplyds)
Around central stars Analogous to the solar nebula |
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73. What is the oldest thing in our solar system?
What are theories of planetary formation largely based on? |
Meteorites (4.5 Ba)
The solar system |
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74. What would an all encompassing theory account for?
Does one exist yet? |
Composition, size, position relative to star of all extrasolar planets
No |
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75. What are giant molecular clouds?
What have been observed in them? Where is the closest large molecular cloud? |
Regions of gas and dust that are dispersed amongst our galaxy
Proplyds Orion Nebula (less than 1 million yrs old so planets are still forming) |
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76. What composes molecular clouds?
How are molecules bound in the coldest parts of clouds? How are molecules bound in most parts of clouds? |
Mostly of gas of H and He
Bound in very small rocky-icy grains Bound in small rocky-icy grains or as gas |
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77. What happens in the densest and hottest parts of these clouds?
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Star formation
Stars form in clusters of thousands to millions in cores of giant molecular clouds |
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78. Where do most proplyds (and planets) form?
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Around most stars from surrounding dust (silicate mostly) and ice
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79. How does star formation occur?
Six steps |
1. Molecules in dense clumps in cloud begin to collide
2. Clump attracts more matter by gravity 3. Motion of collapse and collision (kinetic energy) is converted to heat 4. Temperatures and pressures rise 5. These conditions initiate fusion of H into He and release of energy 6. Energy release creates outward pressure until hydrostatic equilibrium is reached (stable star) |
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80. What do stars older than a few million years not have?
What does this mean in terms of planetary formation? |
Don't have proplyds
Planets must form "rapidly" following proto-star formation |
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81. Which type of planets form quicker?
What do gaps in protoplanetary disk indicate? |
Gas giants form quicker as they have lots of H and He from solar nebula
Presence of planet |
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82. From where do planets initially form?
What does almost everything in the Universe do? |
Spinning clouds of gas (proplyds) associated w. star formation
Spin or rotate |
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83. If the spin rate becomes too fast what can happen?
What happens if the spin rate is very high? |
In fall by gravity, gas and dust is forced out and thrown into orbit around star
Two stars may form (binary star) |
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84. How long must planet formation take?
Why? |
A few million years
Stars older than this don't have proplyds |
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85. After a few hundred thousands years of in fall of gas dust, it start to slow considerably and then what happens?
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Wind of charged particles from star(s) acts to erode disk from inside out
*Solar wind is a remnant of this Also, spectacular jets are formed at the poles of the newly-formed stars |
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86. After the jets, what forms next?
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Planetesimals form within disk from grains of rock and ice
*Gas giants formed at this time before most of gas of disk was blown away |
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87. When do the planetesimals begin to accrete?
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When the protostar stops growing and the vigorous winds from the star have largely abated
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88. What do jets do?
How do they affect planet formation? |
Force most dust and gas outwards
Erode proplyd from inside out Most planets have to form before have jets have eroded disk too much Planets w/ lots of H and He have to form before these jets get going |
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89. What is accretion initially due to?
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Stickiness of small ice-coated grains, then gravity takes over
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90. When was the impact rate great?
How do we know of the Heavy Bombardment phase? Why is the onset of solar winds important? |
During early solar system (heavy bombardment)
Recorded on many surfaces (Moon, Mercury, Callisto) Composition of disk, temperature of disk, and timing of accretion relative to solar wind onset |
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91. How is the temperature in in the innermost disk?
What can condense here? What can condense beyond 5 AU in today's solar system? |
High due to fusion
Silicate and metal grains can condense Ice |
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92. What is one explanation for the origin of the gas giants?
What may have happened to Neptune and Uranus? |
Began as rocky-icy bodies which grew so large that they could attract some of surrounding nebula gas
Uranus and Neptune may have ran out of gas (which was dissipating in the solar wind) |
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93. What caused planetary accretion to cease?
What happens following planetary accretion? How does this happen? |
Dissipation of rock and icy grains by solar winds and gaps in disk due to planetary accretion
Planets evolve (composition and structure change) Gas release and chemical differentiation (heavier elements sink to core) |
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94. What does differentiation give rise to?
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Layers of planets (core, mantle, crust)
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95. What type of star is the Sun?
How old is it? How are stars held together? How are stars powered? |
G2 star
~5 billion yrs old (die out by ~10 billion yrs) By gravity Nuclear fusion of H in cores |
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96. How massive is the Sun?
What is the composition of the Sun? |
Contains more than 99.8% of total mass of the Solar System
H (75% by mass) and H (25% by mass) -minor amounts of heavier elements |
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97. What is the rotation of the Sun like?
What is the axial tilt of the Sun? |
Prograde rotation (counterclockwise)
-differential rotation -shorter at equator than poles Inclined 7 degrees from ecliptic (large impact) |
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98. As you go deeper into the Sun what happens?
Where is all the energy in the Sun created? |
Increases in...
-temperature -density -pressure In the core -flows outward through sun |
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99. By what three ways does energy flow from hot regions to cold regions?
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1. Conduction
2. Radiation -radiation zone: radiative heat transfer, composed of ionized gases 3. Convection -convection zone: active circulation of gases and convective heat transfer to the sun's surface |
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100. What is the outer shell of the sun we see?
What is the visible surface of the sun? What is the Sun's atmosphere? |
Top of the turbulent convective zone
Photosphere (yellow "surface") -5500 K surface temperature Photosphere, Chromosphere, Corona, and Solar Wind |
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101. What are sun spots?
Why are they dark? What is the average size of a sun spot? How do they form and last? |
Dark spots on the photosphere that contain intense magnetic fields
Cooler than surrounding photosphere (4000 K) 2 Earth diameters Form in groups of up to 100 individual spots Last as long as 2 months or more (about a week) |
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101. What is the center of a sun spot called?
How is it in compared to the outer part? |
Umbra
Umbra is cooler the penumbra |
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103. How is the surface of the photosphere?
What are these things? How longs does each granule last? |
Mottled by pattern of bright cells called granulation
Surface expression of underlying convection cells 8-10 minutes |
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104. How bright is the chromosphere?
How hot is it? When is it visible? |
1000 times fainter than photosphere
Higher than photosphere During solar eclipse |
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105. Why do the chromosphere and corona have such high temperatures?
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Difficult to explain
Related to heating during release of energy from photosphere released along "magnetic loops" (largest are prominences) |
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106. What are prominences?
How do they appear? What are they controlled by? What do they represent? |
Red protrusions of ionized gases from the chromosphere
Commonly looped Magnetic fields Twisted magnetic fields emanating from the active regions around sunspots |
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107. What are solar flares?
How long do they last? |
Chromosome eruptions (not looped) of...
-ionized gases -x rays -UV light -visible light Rise rapidly in a few minutes then decay over an hour or less |
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108. How do solar flares affect the Earth?
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Most flares become "gusts" in the solar wind and reach Earth after a few hours or days
Create magnetic storm on Earth that affects communications and increases auroral activity |
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109. What is the corona?
What is it composed of? How hot is it? When can we see it? |
Outermost part of Sun's atmosphere
Very low density ionized gases Temp rise rapidly outward in corona (5000K to 3,000,000K) Milky white glow visible during total lunar eclipse |
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110. What are solar winds
What are they composed of? How far do solar winds extend? How can solar winds affect Earth? |
Rapidly moving outward extension of the corona
Ionized H called plasma (carries away 1 million tons of solar matter per sec) Interplanetary space for >80 AU "Gust" (assoc w/ solar flares) cause magnetic disturbances on Earth |
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111. When did we first detect extrasolar planets?
How are most of the planets we've found? Why is this the case? |
1994
Large Jupiter-like planets that are close to stars Large ones have been found so far b/c influence of planet's gravity on star |
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112. What is the main way we detect extra-solar planets?
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Detect by influence of planet's gravity on star
Detection of smaller planets influences of this type not yet possible |
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113. How do we detect large extra-solar planets?
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1. Doppler Spectroscopy
2. Astrometry 3. Transit photometry 4. Optical interferometry 5. Pulsar timing |
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114. How is Doppler spectroscopy used?
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Measure small changes in spectra of starlight induced by movement away and towards observer of star
Due to gravity of nearby planet Most common method to date |
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115. How is astrmetry used?
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Measure actual shifts in position of star relative to distant stars
Due to gravity of nearby planet |
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116. What is transit photometry?
What will this be the main method to detect? |
Study of changes in amounts of light received from a star when planet passes in front of it
Earth sized planets in future |
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117. What happens in optical interferometry?
What is this similar to? |
Light from star is blocked out in hope that light reflected off planets can be seen
Similar to method used to observe corona of Sun |
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118. What method was used to detect the first extra-solar planet?
How does this work? |
Pulsar timing
Planets orbiting pulsars influence timing of pulses of light |
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119. How far are most extra-solar planets from their star?
How are the orbital periods of most extra-solar planets we've found? How are the orbital eccentricities of extra-solar planets? |
Very close (<1 AU) - many are closer than Mercury to our Sun
Short periods (few days) Extreme eccentricities (larger ones than gas giants in our solar system) |
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120. Why do extra-solar planets have large eccentric orbitals?
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We don't know yet
Probable that the near-circular orbits in the solar system are unusual |
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121. What are the sizes of most extra-solar planets found?
What are the masses of most extra-solar planets found? |
1-10 times Jupiter's size
Bodies of 13 or more Jupiter size typically become stars 0.3 to several Jupiter masses |
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122. What is the atmosphere of extra-solar planets like?
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1. H-rich atmospheres detected
2. Such atmospheres are probably common around "hot Jupiter-like" planets 3. Sodium also detected in atmosphere of an extra-solar planet 4. Comet like jet atmosphere expected in gas giant planets close to their stars |
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123. How can we find Earth-sized and Earth-like planets?
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1. Look around G-type stars
2. Detect atmospheres w/ N, CO2 like Earth |
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124. What have extra-solar planets told us about planet formation?
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1. Many very large planets have been found very close to stars (not yet clear why)
2. Extended jet-like atmospheres of "gas giant" planets close to stars suggest most found so far may be young |
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125. What will Terrestrial Planet Finder (TPF) detect?
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Water, carbon dioxide, oxygen, ozone etc in atmosphere within "habitable zone"
Can search >200 stars at once |
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126. What has driven search for life on other planets?
Seven things... |
1. Discovery of water on Mars
2. "Nannofossils" in Martian meteorite 3. Transfer of "biomolecules" across planets by asteroids and comets 4. "Oceans" on Europa and Ganymede 5. "Biomolecules in chondrites, comets, molecular clouds, etc. 6. Numerous extra-solar planets 7. Life in many extreme environments on Earth |
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127. What will detecting the signature of life on extra-solar planets rely one?
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Analysis of spectra of starlight passing through their atmosphere
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128. What is astrobiology?
What else does it involve? |
Science of life (or possibility of) on other planets
Study of origin of life on Earth and extremophiles |
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129. What are extremophiles?
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An organism that thrives in extreme environments on Earth
Extreme environments on Earth may be "normal" on other planets |
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130. What are likely places in the Solar System for the possibility of life?
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Mars
Europa Titan |
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131. What are biomolecules?
What do they include? Where are they found? What else is a common molecule in the Universe? |
Essential to life on Earth
C-H-N-O based molecules and includes amino acids They are everywhere (comets, asteroids, giant molecular clouds) Water |
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132. What is the habitable zone?
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Area of planetary system where P and T conditions allow for liquid water
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133. How does the habitable zone change?
What is habitability dependent on? (Five things) |
Changes with time (HZ shifts with time)
1. Position from Sun 2. Local atmosphere conditions 3. Tidal heating 4. Greenhouse heating of ice by stars 5. Consider habitability of surface |
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134. What are some conditions necessary for life?
Four things... |
1. Water and energy to build polymers that can store information
2. On Earth life required liquid water 3. Concentrate biomolecules 4. Protect polymers from UV |
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135. Why is the existence of extremophiles important?
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Shows that "extreme" conditions of T, P, salts, dryness, etc. are not a problem
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136. What are four environments for origin of life on Earth?
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1. Hot dark deep sea vents
2. Lakes and lagoons 3. Mineral catalyst -clays, pyrite, etc. for construction/protection of large molecules (RNA) 4. Panspermia ("seeds of life everywhere") -biomolecules brought to Earth on comets, asteroids, meteors |
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137. Would things could indicate extraterrestrial life?
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1. Obvious lifeforms (from landers)
2. Disequilibrium in atmospheric composition -oxygen/ozone from photosynthesis |
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138. What are halophiles?
Where are they thought to possibly be? |
An organism requiring salt (NaCl) for growth.
On Europa - suggested that red color of the ice is due to halophillic organisms |
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139. What are barophiles?
What do these organisms require? Where may they be found? |
Organisms (including complex multi-cellular eukaryotes) that can survive in extreme pressures
High P to survive (upper P limit is unknown) Bottom of Marianas Trench (ocean floors) |
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140. In what type of environment do acidophiles thrive?
How do they survive in this? Where are acidophiles found? |
pH < 2 (some at pH close to zero)
Keep acid out of their cells Acid hot and cold springs, hydrothermal vents, areas of acid mine drainage, stomach acid |
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141. In what type of environment do alkalophiles thrive?
How do they survive? Where are they found? |
At pH > 10
Maintain pH neutrality in the cell interior Alkaline (soda) lakes |
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142. What are xerophiles?
What is one of the best known examples of a deposit generated by xerophilic bacteria? |
"Dry-adapted"; grow at very low moisture levels
Desert varnish |
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143. What is desert varnish?
What does understanding desert varnish have implications for? |
A layer of clay, Fe-oxide and Mn-oxide precipitated by xerophilic bacteria
Implications for understanding life on Mars (very dry at surface) |
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144. What are thermophiles?
What have the highest T range? Up to what temperature can known eukaryotes survive? |
Organisms that can survive at high temperatures
Archaea (temps >90 C) 70 C |
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145. What are hyperthermophiles?
What do these organisms utilize and why? |
Organisms that thrive in boiling or near-boiling water (>90C)
Utilize sulfur -no O in such high T water |
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146. What are psychrophiles?
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Organisms that thrive at low temperatures
"Cold-adapted" |
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147. What are some familiar psychrophiles?
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Snow algae (eukaryotes)
-thrive at T's around 0C Psychrophile bacteria commonly grow in your freezer |
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148. Where are endolithic bacteria and algae found?
Where do they live? |
Dry and cold environment
Near-surface of pore-spaces and grain boundaries of rock which provide a protected environment |
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149. Where are anaerobic bacteria found?
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Thriving in rock at 3.5 km in South African goldmine (deepest know to date)
Grow in absence of free oxygen |
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150. What is the "deep hot biosphere"?
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A deeper (>1km) biosphere now recognized
Suggested that oil is generated by bacteria/archaea in deep Earth |
