Astronomy 2

• volcanism- volcanoes and volcanic eruptions
• meteor impacts- craters

• craters form 20 times bigger than the object that caused the crater
• 1. punch bowl/simple crater- smallest, usually caused by objects less than 1 mile in diameter
• 2. central-peaked crater- group of mountains in middle of crater, created by objects 1-5 miles wide
• 3. multi-ringed impact basin- largest, multiple rings spread out from center, at least 5 mile wide impacter

crater count- counting amount of craters in an area and dividing that number by the area

• produce a crater
• blast huge amounts of dust and molten rock into the air
• molten rock raining down would raise the surface temp extremely high causing global wildfires
• hot fragments and blast would create nitrogen oxides which would combine with water to form nitric acid rain
• the toxic combination of heat, acid rain, and blast would be followed by months of darkness and intense cold caused by the dust shroud blotting out the sun

• erosion- wears away rock and other surface materials (if the earth had no geological activity to rebuild mountains, the action of rain, flowing water, and waves would have gradually ground down the earth until the entire surface would be under water)
• volcanoes- lava flows smooth out the surface

• smoothed out areas on moon that are completely devoid of water
• largest volcanic feature
• flood basalt

• largest volcano is solar system
• found on Mars
• shield volcano (most common)

• most common
• least violent eruptions
• large craters in center (caldera), irregularly shaped unlike impact craters

• large crater in center of shield volcano
• irregularly shaped unlike impact craters

180 km (110 mile) wide crater found in Yucatan region in Mexico

the region of space surrounding a planet where its magnetic field deflects away the solar wind

the area between a magnetosphere and an ambient medium

the abrupt boundary between a magnetic field and surrounding plasma

formed by pressure from the solar wind on a planet's magnetosphere

• no heat left
• no volcanic activity
• no plate tectonics

• some heat left, still hot inside
• volcanoes, quakes, plate tectonics still occur

• solar day- 176 earth days
• orbital period (year)- 87.969 earth days
• rotation period- 58.646 earth days
• spins three times for each two trips it makes around the sun
• the day is longer than the year

• the iron core is based on its density
• although a massive planet's gravity can compress its interior to high density, Mercury is too small for this effect to be significant. therefore its high density indicates an iron-rich interior with only a think rock mantle

• giant (mile high) cliff on Mercury and the moon (but not as big)
• the planet cooled and shrank, wrinkling, crust collapsed into mantle causing scarps

• its gravitational attraction is too weak to retain any significant amount of gas
• its closeness to the sun makes its temp higher which in turn causes any gas molecules there to move so rapidly that they readily escape into space

• a magnetic field is generated by circulation of electrically conducting material in a planet's interior
• mercury is too small to have a molten core therefore, the outer iron core may be mixed with sulfur which can lower the melting temperature

Venus had a faster retrograde spin in the distant past and the sun's tidal effects slowed it down to its current rate

volcanoes

• highland region on Venus
• located near Venus' equator

• highland region on Venus
• studded with volcanic peaks

• volcanic peak on the ishtar terra of Venus, including tallest volcano
• only male name on Venus

large, crown-like volcanic features on Venus

• 96.5% C, 3.5% N, trace amounts of water vapor and other gases
• lightning storms, but no rain
• clouds composed of sulfuric acid droplets
• clouds permanently cover the planet and are very high and thick (cannot see through them with ordinary telescope)
• below clouds, atmosphere is relatively clear and some sunlight penetrates to surface
• pressure 90 times that of earth's
• >900 degrees F, 500 degrees C

• greenhouse effect- heat enters the atmosphere, but does not leave
• heating has driven the temperature up, and the heating has led to an even stronger greenhouse effect
• happened to Venus (Venus' surface is hotter than Mercury's even though it is further from the sun)

• no. it does not have a dynamo which requires a conducting liquid, rotation, and convection
• Venus lacks convection in the core

• convection- circulating movement of a heated liquid or gas
• rifting- the mantle stretches and spreads the crust, breaking apart
• subduction- one plate is driven back down into the mantle
• volcanoes
• earthquakes

• plate tectonics
• convection

• atmosphere is 80% N2 and 20% O2
• it currently has plate tectonics
• it's livable

• 80% N and 20% O
• troposphere- dense lowest layer of atmosphere where water vapor circulates, clouds form, and the air is very turbulent
• stratosphere- stable layer above troposphere which contains gases such as ozone to shield the earth's surface from most of the short-wavelength radiation from space
• inonosphere- where most molecules and atoms have been broken apart into ions

it has a magnetic dynamo process which is generated by electric currents flowing in its molten iron core

• southern cratered highlands
• northern lowlands

an uplands region spanning the equator of Mars about the size of North America

• an enormous rift along the equator of Mars
• would span the continental US

• 95% CO2 and 3% N with traces of O and H2O
• similar to Venus' but far less dense
• -80 to -140 degrees F
• clouds made of dry ice and water ice crystals
• no rain
• thinned due to: weak gravity, ablation, dry ice

Mars may have had a denser and warmer atmosphere in the past, allowing liquid to exist. when Mars lost it's atmosphere cause the planet to plunge into a permanent ice age. gas molecules escaped and water molecules evaportaed. as Mars cooled, the remaining water froze solid and wind buried the ice under protective layers of dust

yes. it's axial tilt produces a pattern of seasons similar to earth's, but more extreme because the atmosphere is much less dense

90% H, 10% He

it has deep circulation (convection currents carry warm gas upward and into space, as it cools, it sinks back down) and rapid rotation

• ammonia ice
• ammonium hydrosulfide
• water

• whitish yellow bands of clouds made of ammonia ice
• found on jupiter

• dark orangeish brown bands of clouds made of ammonium hydrosulfide
• found on jupiter

• turbulent storm, twice as big as earth
• high pressure system unlike hurricanes and cyclones
• found on jupiter

convection in the metallic liquid hydrogen combines with the planet's rapid rotation which is driven by a natural dynamo process

• yes
• narrow "bright" ring (main) with sparse, broad rings (Gossamer Rings)
• composition- dust

maintain rings, prevents particles from spreading out and dispersing

• 63
• they aggregated from planetesimals and gas that collected around the gas giant during formation or were captured after passing by closely to the planet

• 96% H and 3% He
• cloud composition is ammonia and water
• has shepherd moons orbiting amongst rings
• turbulent storms
• oblate spheroid (egg-shaped)
• 62 moons

• Saturn has less prominent zones and belts
• Saturn has more rings

countless small particles made of ice and dust

62

• half the size of Saturn
• tipped on side

• rich in hydrogen and helium and 2% methane
• methane gives it it's color

a giant impaact