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43 Cards in this Set
- Front
- Back
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What species of bacteria survived harsh conditions in space?
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Streptococcus
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What conditions did Streptococcus survive?
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Space launched
3 years of space vacuum Radiation exposure Deep-freeze No nutrient, water, or energy |
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Most heat-loving hyperthermophile known lives best at what temperature?
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105 C
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Astronomer who accidentally fueled the thought that there were canals on Mars
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Giovanni Schiaparelli
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First spacecraft to make a successful flyby of Mars
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Mariner 4
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How does the radius of Mars compare with that of Earth?
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Half that of Earth
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How does the mass of Mars compare with that of Earth?
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10% that of Earth
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How does the surface gravity of Mars compare with that of Earth?
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37%
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How long is the Martian day?
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About the same as an Earth day
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How long is a Martian year?
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1.88 Earth years
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Composition of Martian atmosphere
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95% CO2
Less than 3% each of: N2, Ar, O2 |
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Mars receives ___ times less sunlight than Earth does.
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2.3
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Due to a very thin atmosphere, the Martian greenhouse effect warms the planet _____.
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5 C
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Largest volcano in the solar system
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Olympus Mons
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The upper crust of the Martian ice caps is made of...
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Dry Ice
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If the Martian ice caps melted, the planet would be covered in water ____ deep.
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11 meters
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Each Martian year, the polar ice caps on Mars...
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shrink
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Why did Mars end up unlike Earth?
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1) Weaker gravitational field
2) More rapid cooling of molten interior |
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The first direct test of life on Mars was what project?
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The Viking Project
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The Viking Project made what assumptions about Martian life?
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(1) That it is carbon-based.
(2) That is has chemical composition like Earth life. (3) That it metabolizes simple organic compounds. |
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Results of the GCMS
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Martian soil has virtually no organic material
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Three Viking biology experiments
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GEX
LR PR |
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Viking experiments: GEX
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Touched soil with nutrients and measured gas products
Result: A lot of oxygen produced, but control had same result. |
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Viking experiments: LR
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Use nutrients with radioactive carbon atoms.
Result: Sudden rise in gas radioactivity. With more nutrients, decrease in radioactivity followed by a slow rise. Control did not show same result. |
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Viking experiments: PR
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Soil sample placed in simulated Martian atmosphere. Tested to see if any organisms had ingested radioactive Carbon.
Result: Showed that radioactive Carbon had apparently been ingested. But control showed same result. |
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Lessons from Viking
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1. It is difficult to distinguish biochemical reactions from chemical reactions
2. Even the hardiest of Earth extremophiles would find it tough to adapt to the Martian surface 3. Results don't rule out life on Mars |
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Why didn't Viking rule out the possibility of life on Mars?
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1. Strong evidence of underground water
2. Water may be closer to the surface in the polar regions |
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Phoenix
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Dug a trench in northern polar region
Found chunks ice that sublimated away over time Found perchlorates in soil |
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What type of extremophile could thrive in the watery Martian underground?
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SLiME
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Meteor from Mars, possibly with fossilized life
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ALH 84001
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ALH 84001 was discovered where?
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Antarctica
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Why have the majority of the world's collection of meteriorities come from Antarctica?
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Easy to find because:
Largely featureless surface Lack of human activity |
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Group of meteorites from Mars
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SNC Meteorites
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How many SNC meteorites are there?
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30
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How do we know SNC meteorites are from Mars?
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They have pockets of gas that match the composition of the Martian atmosphere as measured by Viking.
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The claim of ancient life on ALH 84001 is based on what five pieces of evidence?
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1. Carbonate resembles crystals produced by bacteria on Earth
2. Carbonate structures that look like fossils 3. Small particles of magnetite that resemble magnetite made by bacteria on Earth 4. Formation of carbonate, iron sulfide, and FE3O4 (iron oxide) minerals in globules 5. Globules contain complex organics known as polycyclic aromatic hydrocarbons that have been identified as the decay products of Earth microbes |
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The Martian Face was found where?
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Plains of Cydonia
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Jupiter's four largest moons
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Io
Europa Ganymede Callisto |
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Jupiter's moons: composition
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Io: rock
Europa: mostly rock with some ice Ganymede, Callisto: ice mixed with rock |
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Io: Characteristics
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(1) Caught in a tug of war between the gravity of Jupiter and Europa/Ganymede
(2) Slightly elliptical orbit (3) Immense tidal heating making it the most volcanically active place in the solar system |
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Europa
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(1) Some tidal heating
(2) Young surface (3) Ice with more ice, liquid water, or slush beneath |
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Why can't liquid water exist for long on the Martian surface?
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Low atmospheric pressure
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Many of the channels on mars were formed when?
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4 billion years ago
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