ASTRO final
orbits change from interaction with jupiter
- objects that jupiter has kicked out = populated oort cloud. jupiter may not be solely responsible for oort cloud tho
You learned that up until about 30 years ago, the origin of our Moon was hotly debated. This debate was eventually addressed in a conference where the participants narrowed down the possible formation scenarios to just four, and by the end of the conference, had zeroed in on just one theory for the Moon's formation. (1) List the four original theories proposed for the formation of the Moon and highlight the one theory that eventually prevailed. (2) Choose one of the three theories that failed and describe the reasons for its failure - in other words discuss the constraints that it failed to address. Be sure to include details in your discussion.
-Co-accretion: This theory suggests that the moon and earth were formed together from a primordial cloud of gas and dust. -Capture: This theory proposes that the Moon was formed somewhere else in the solar system, and was later captured by the gravitational field of the Earth. -Fission:This theory proposes that the Moon was once part of the Earth and somehow separated from the Earth early in the history of the solar system. This failed because the mass of the moon was too big. -Giant Impact: A Mars-size object crashed into the Earth and merged with Earth's disk of debris from the mantle of both worlds and accreted into the moon. This theory was the only one to not fail any category, however received B's in most categories. CATEGORIES: Mass of the Moon, Angular Momentum, Orbital Inclination, Lack of Volatiles, Lack of Iron, O Isotopes, Magma Ocean, and Physical Plausibility, co-accretion, capture, and fission all failed at least three of those categories. -Giant Impact Theory passed all of the types except for an incomplete except for the size of the moon because it was unclear what size moon a giant impact would actually take.
You learned that there are two distinct types of planetary atmospheres: primary and secondary. You'll hear more about worlds with primary atmospheres after the midterm, as well as a few more with secondary atmospheres. (1) List the worlds with secondary atmospheres you've learned about so far. (2) For each of the worlds you listed in (1), describe the most likely original composition of the world's atmosphere after hydrogen and helium have escaped the world (which happens fairly quickly). (3) Choose one of the worlds you listed in (1) and describe the process(es) at work over the last 4 Byrs to change its atmosphere from the original composition you described in (2) to its current composition as seen today.
-Earth, Venus, Mars have secondary atmospheres today -Earth: Water, Methane, Ammonia, Oxygen, Nitrogen, Carbon Dioxide -Venus: Water, Methane, Ammonia, Oxygen, Nitrogen, Carbon Dioxide -Mars:Water, Methane, Ammonia, Oxygen, Nitrogen, Carbon Dioxide *****On Earth: -Earth's atmosphere interacts strongly with its surface, eliminating CO2 from the atmosphere over time (reducing atmosphere) -Rise of oxygen took time to build up in the atmosphere becuase it was first oxidized and rusted the metals in Earth's crust -Oxygen atoms also bonded to form an Ozone which protects the earth from water dissociation for the last 2 Byrs -Rise of oxygen also due to it being a by product of LIFE -Processes at work: weathering, chemical reactions, condensation, human impact -Elements added by outgassing: water (H2O), Cl2 (chlorine), carbon dioxide (CO2), Sulfur dioxide (S2), nitrogen gas(N2) temperature right for formation of liquid water = oceans O2 trapped in to form liquid H20 -The CO2 released by outgassing→ dissolved in the liquid water to produce carbonate rocks -CO2 gone due to weathering and plant life→ atmosphere became primarily N2 based -CH4 is increasing on Earth due to the waste products of animals and agriculture (greenhouse gas)
The Moon is often referred to as the "Earth's Attic". Much like how your grandparent's attic likely contains old photos, trophies, antiques, and other memorabilia, all documenting in some way the past history of your family, the Moon stores the past history for the Earth and the rest of the terrestrial worlds of the inner Solar System. (1) Describe in detail one piece of that history that is retained on the surface of the Moon but has been lost from the surfaces of the terrestrial planets. (2) Your response should include why or how that evidence is retained on the Moon and why or how it was lost (erased?) from the surface(s) of the other world(s)
-evidence of asteroid and comet impacts and still maintians its ancient landscape - unlike other terrestrial planets whose surfaces are constantly recycled -on earth, there is little to no evidence of asteroid or comet impacts -Plate tectonics alter Earth's solid outer crust, creating motions that destroy rocks and some of Earth's surfaces -Other envoronmental factors alter Earth's landscape, including eind, flowing water, and glaciers which wear away the surface -the Moon's static environment preserves rocks from its origin; this enables the Moon to be used as our ancient world proptype, as it is constant and does not change.
You've heard the phrase 'geologic activity scales with size' numerous times now in this course. When we compare two terrestrial worlds, like the Earth and Earth's Moon for example, we clearly see a striking difference in both the type and scale of geologic activity expressed on their surfaces. Explain what this phrase means in terms of both (1) the radioactive decay of isotopes in the interiors of the Earth and Moon and what it means in terms of (2) the surface-to-volume ratio of these worlds. (3) Finally discuss the various processes at work to modify the surface today for each of these two worlds.
-just knowing that simple number will allow us to predict the level of and length of time that geologic activity will last on a world -large worlds like Earth and Venus, will express much more geologic activity on their surfaces and that activity should last much longer than the geologic activity seen on smaller worlds like Mercury or the Moon -Large worlds have a larger percentage of radioactive isotopes in their cores and therefore produce more heat (larger the world, the more radioactive isotopes, the more heat it will produce) -small surface areas compared with their large volumes forces them to release that heat to space much more slowly. -large worlds stay warm and drive geologic activity on their surfaces in the form of volcanism, tectonics, and so on, much longer than small worlds-surface gravity of a world is more strongly influenced by a size than its mass -we should see evidence of a level of geologic activity that is greater than that observed on either Mercury or the Moon and we should also see that Mars' geologic activity should have lasted longer as well -Earth: geologic activity, human impact, plate tectonics, weathering&erosion, wind -Earth's Moon: solar wind, very little has changed since it was first formed -
5 Stages of Evolution-
1- Origin= initial accretion of world 4.5 BYRs 2- Differentiation- the heavier iron sank to the core, while the lighter silicate minerals "floated" to the surface, thus forming the crust. (4.5-40 Byrs) 3- Late Heavy Bombardment- large object pummeled the surface of the moon (time 3.8) 4- Geologic Activity- period from 3.8-3 BYRs where it appears all of the mare regions were formed 5- The Big Chill- geologic activity has ended, Moon holds all past history of our planet + solar system (2.8Byrs-present) -If we were to take rock samples to gain information from Venus instead of Mars our accuracy and information would either be incorrect or would resurface new and different information every .5 byrs -Venus has such a hot iron core and no water, that the heat inside Venus builds up pushing on the surface ( blob tectonics) until it releases into the the atmosphere -after the heat is released and the surface is melted, the temperature solidifies it back again, erasing all history.
Theme: Top 100 objects (by mass) in the Solar System
1-99 = Sun 100 = Jupiter
nebular theory of star formation
1. molecular cloud begins collapse 2. nebular disk forms, collapse continues, larger objects accrete 3. proto planetary disk continues to form 4. accretion of large objects clears disk 5. solar system emerges
EUROPA
2nd closest to jupiter. smaller than moon, density suggests made of rock, bright surface, cracks ridges, tectonic processes, 12 craters... water ice surface ... strange ridges diagram with liquid and ice being forced out of fracture , welling up and freezing
Everything is Jupiter's Fault
Asteroid Belt exists because of Jupiter - structure is dictated by resonances Comets - 50/50 shot at being ejected from Solar System or thrown into Sun meteorite interactions with inner planets - Earth crossing asteroids scatter of Kuiper Belt objects during dynamical migration & 1:2 resonance with Saturn LHB due to dynamical migration & 1:2 resonance with Saturn Uranus & Neptune, moved and switched position due to dynamical migration & 1:2 resonance with Saturn Mars small mass Rise of humans (mammals) after KT event killed dinosaurs Oort cloud formation from dynamical migration & 1:2 resonance with Saturn delivery of volatiles and organics from the outer Solar System to the inner, volatile poor planets
Importance of all of this to life on Earth
Earth has been a stable environment for over 4 Byrs life needs long-term stability for the development of complex life forms why has Earth been stable for so long? Jupiter!! Mars-sized object hits Earth forming Moon Moon stabilizes obliquity (this may not be as important as we thought...) Moon raises tides - brings life from sea to land 150 Myrs ago two asteroids collide & one part hits 3:1 resonance with Jupiter and is tossed into inner Solar System 10km object hits Earth Eliminating the dinosaurs - our main competitor, 65Myrs ago Geologically active Earth results in big magnetic field know the "key ingredients" for generating a magnetic field and why some worlds have one and some do not magnetic field protects biology from high energy particles/radiation from the Sun good for long term development of complex biology on the planet
Jupiter-sized planets have a big impact on the development of stellar systems
Jupiter formed at 3AU volatile condensation point formed with a lot of material and quickly (~10Myrs) other three giants formed very near by understand the Nice Model and its importance & connection to exoplanets
resonances with neptune change orbits of KBO's.
KBO hits jupiter and is destroyed, or tossed toward sun;/solarsystem
TITAN
LARGEst satellite of saturn. second thickest in atmosphere- numb ear one is venus. same mass and gravity of moon tho cause it holds atmosphere correct temp and gravity ... low gravity 10 au from sun = cold, formed far below snow line where solid surfaces made mostly of rock , 90% atmosphere, clear gasses
craters... just copied and pasted form the web tho
Lunar impact craters come in three basic types: simple craters, complex craters, and basins. Simple craters are what most people think of when they visualize a crater. They tend to be bowl-shaped with rounded or small, flat floors. Simple craters also have smooth rims that lack terraces
tritans atmosphere...
N2 molecule tripple bond is nearly 2.5 times stronger than singly bonded methane so n2 in titans atmosphere is almost unaffected by UV photons and exist for millions of years. CH4 and methane is dissociated by sunlight and recombines as smog..... atmosphere modified by light
TRITON
NEPTURES ONLY REGULAR SATELITLES . smaller than moon, more rock that ,out icy satellites crater density is 0. young. tectonic cracks like enceladus
ages beyond snow line
Observations of the asteroid belt, located between Mars and Jupiter, suggest that the water snow line during formation of the Solar System was located within this region.
DWARF PLANETS
SPHERICAL in kb probably looking like triton or pluto or charon, geolicially active. composed of nitrogen and water, ice, organic molecules.
tritons orbit is inclined to neptunes equators like our moon
T formed somewhere else in solar system as it orbited around sun got to close to sun and gravitational encounters launched small companion, and Trton bound to neptune
how j got big
`accrete a big core about 10 earth masses which has to happen fast in one place. in ring of material no more than .5 AU in width just beyond snow line. made f mostly water, driven from regions closest to sin can solidify and build planets. gravity strong enough to hold light elements like h and he which makeup atmosphere
th earth has a magnetic field which can also be seen as
a windshield from the solar wind. protects our atmosphere
Little objects accrete to make big(ger) objects
accretion is how you build objects from the Solar Nebula accretion times depend on distance from the Sun know how this affects how you grow Uranus & Neptune and why Kuiper Belt is not one solid object
planets moving
all 4 gas giants formed close to each other within part of proto disk jut beyond snow line where increase in material and lots of water and volatile ices too condense. providing material can build quickly. green and gravitationally influences each other, ejecting them from porto-disk to. populate oort cloud
The Snow Line
at ~3AU just outside of the Asteroid Belt a massive amount of volatiles become solid and available for planet-building inside refractory elements dominate
where material came from
big bang! birth of entire universe. material is found in galaxies in arms of serial galaxies
pluto satelite
charon- two different worlds with theme of young surface and signs of geologic activity
meteorites come from parent bodies... list types
chondrites, ordinary chondrites, achondrites
tritons cry volcanoes
cold, 30 AU from sun, gasses like nitrogen can solidify, reflectance says surface made of nitrogen ice. acts like greenhouse gas like CO2 when frozen its solid
The Solar System formed out of a flattened disk of material
collapse driven by nearby supernova explosion understand the evidence for this
iron meteorites
completely iron. on inside, etched with light acid. acid reveals crystals. how fast parent body is cooled related to surface area volume ratio
lo's interior issssssss
completely molten, lo distorts jupiters magnetic field and volcanos are its way of releasing all heat being generated or trapped. lava repaves lava is black when hot white when cool
magnetic field consist of
conducting material-fluid internal energy source for convection-heat moderatley fast roation
triton is hella extra and requires
constant source for replenishment . has a wild surface like a fukin cantaloup with dark streaks and small opening . has no crater tho and is smooth af. mostly nitrogen traces of methane but not out of irdinary for icy world
active worlds
crater saturated areas like lunar highlands, also young, mare regions. factures/rifts, scarring surface, evidence of shifting overline
MIRANDA
discontinuities, fractures. external. force- initial formation, giant impact shattered world, eventually reassembled like asteroids in bold. internal force- tides- gravitational interacts with uranus and other satelittles to change orbit to elliptical involve ides on surface of world, heating interior to create upwellings of liquid differentiation- world frozen in time. so small maybe ran out of internal heat and cooled while sorting out interior
tidal heating
distorts world into football shape. resonaces changes orbit ... lo's distance from jupiter = constantly changing . force of front and back too. 2 day orbit of football to circle. lots of internartion heat via friction. like kneading dough
internal structure of giant gasses
driving winds, belts, zone, boiling contraction- still forming, accreting, shrinking masses enough to drive up pressures and temps in interior extreme conditions of interiors of these worlds result in exotic forms of matter
carbonaceous chondrites have the same abundances as
elements of the sun. chondrules wouldn't have survived if the object was ever heated. objects first bodies to accrete as solar system. unchanged
lo doesnt orbit jupiter by itself. has many satellites
europA! lo is the closet tho. gravitational ave of e changes lo's orbit and feels maximum fore from E at work to change the orbit of lo
meteorites fall...
everywhere. not all collected. can land in water, covered with trees, dry deserts, antarctica where ice sheets pile up
big difference about regular satellite
formation mechanism. all formed co accretion with parent planet. composition, formed far beyond snow line that they gave larger rock content still mostly icy tho. orbits circular above quarter
jupiters size
formed beyond snow lines when ice can condense. jupiter and rest of gas giants has more resources/ice/ than terrestrial planets. can build big worlds beyond snow linee
when high energy particle feet reaped by magnetic fields...
found in belts circling planets outside of planets atmosphere. called van allen belts.... intense radiation!
magnetic field generated in cores of worlds. as planet spins on acid....
frees electrons currents in metallic cores and more to generate magnetic field
comets are made up of
gaseous molecules that glows blue and dust&rock debris that liberates from comets surface made of ice with some rock. see them at night and slowly disenergrate
as distance between any two objects decreases...
gravity force increases
greenhouse gas
greenhouse ices are good at trapping radiation form the sun but let higher energy like UV pass thru
titan is like earth as it
has land and liquid, seas. world with atmosphere ,modified by sun interacting with surface and surface modified by liquid
europa and titan...
have liquid water beneath icy crusts
planet not toasting
heated more by direct rays from sun. warmer than polar regions. cool air at sinks and moving toward equator. this creates two larger cells of circulation - one in each hemisphere called hadley cells ----which is how venus' atmosphere works because spinning slowly on acid . not realistic for other planets
titan has a lower density and it is closer to the core with....
higher density material near its crust. it is like a basketball. pressure and temp are perfect in interior for water to bw in liquid phase so low density in its interior is like to have liquid water
long period comets
highly inclined orbits, protograde or retrograde! from oort cloud- sphere of material surrounding sun and explains why random trajectories of orbital inclinations of long period comments
achondrites
highly modified, altered by heat, composed of basalt, anorthosite, and impact breccia, born of energetic geologic processes which produce a lot of heat
ENCELADUS replenished by
icy jets of material seen escaping polar regions wobbles while orbiting saturn is called liberation. reveals ocean is likely global and crust is detached or floating on liquid water
disk of milky way
illuminated by bins of starts. some light blocked by large amounts of gas and dust. in spiral arms = main inregideents to build solar system
Condensation temperature dictates what materials are available to build a body
inside snow line = rock & iron outside snow line = ices & rock & iron what you accrete depends on where you are accreting
VAN ALLEN BELTS OF JUPITERE
j's magnetic field is powerful enough to strip material from lo's surface but belt makes it unlikely that we will explore these surfaces
different colors of atmosphere of giant planets
jupiter and saturn uranus and neptune not identical but composed of h and he both are colorless gasses due to various abundances of trace gasses in planets atmosphere differences in gravity. saturn has lower so clouds in saturns atmosphere are more spread out and dull
resonances change orbits
jupiter to AB scattering planetesimals rocky asteroids forming terrestrial rocky asteroids forming into terrestrial worlds
regular satellites
large, co-accretion, prograde and synchronous, low eccentricity (circular), low inclination(orbit above planets equator ), close to planet composition- ice and some rock, not heavily cratered similar to moon
stony iron meteorites
last two classes most severely modified by geologic processes namely by differentiation. mix of rocky material like olivine and iron. RARE. 1% COLLECTED
jupiters atmosphere looks something like
latitudinal flows- lines parallel to equator . have bright- bands and dark- zones violent, turbulent, hurricane like, storms along bound and zone boundaries. boiling water- energy heating driving this motion, sun doesnt provide heat for this circulation
reeflectance spectra for comparison
light reflected from surface, patterns reflected by asteroids. match pattern of meteorite
saturns rings
like asteroid belt, has gaps where ring particles cannot exist for long periods of time because they're pushed out by resonances with nearby satelittles. gaps are maintained by shepherds moons. the gravitational influence of small moons herd saturns f-ring particle and leave behind gravitational wake
structure of saturns atmosphere
like jupiter- same bands and zones and speedy latitudinal flows. differences is occasional storms
Io!
like moons physical properties(density, size, mass, gravity) difference- appearance; no monochromatic grays of basalt and anorthosite, no icy white, past snow line, colorful browns and black = volcanoes
in core of jupiter and saturn at high temp and pressures, it changes into exotic phase ;.....
liquid and metal. exotics metallic cores are magnetic created by induction. to induce, have a current. current/electrons flowing through metal wire
living next to any star is dangerous. the sun is constantly...
losing mass. forms solar wind. stream of material punctated by solar storms, energetic events where high energy particles get mangled. earth is embedded in solar wind.
kuiper belt issues
lots of space, little material, ling accretion time. small amount of mass carets into larger object,. this depends on distance form sun. pluto takes 248 yrs to orbit sun, for objecxrts to accrete, must collide frequently
short period comets
low orbital inclination meaning close to plane of solar system. protograde orbits similar to KB low inclinations.
neptune
made with lower albedo and are a mix of water with organics that redden when exposed to sunlight.
uranus
made with lower albedo and are a mix of water with organics that redden when exposed to sunlight.
meteorites come from...
mars, moon (compare to samples, most impact breccia), rest from asteroid belt -atmospheric sink for mars. AB ring = material that orbits sun between orbits of mars and jupiter
Pluto problem planet
mass small- kepler laws orbit- assuming planets formed with sun, like regular satellites form with parent planets, then planets orbit sun in circular -low eccentricity- orbits above equator of sun... this is true for the first 8 planets
active worlds have less energy to...
melt surfaces of satellites outside now line. means same amount of radioactive elements or less in a world can drive geologic activity longer than icy worlds
worlds with liquid on surface
methane replenished, liquid is located beneath smog, use radar to see
uranus' clouds appearence
more washed out tilted on side due to solar heating panels. uint procuring as much internal heat as neptuneee so lack of structure due to weaker energy in interor
for a world to retain an atmosphere of a particular element ....
must lie on dotted line for the element
KB has resonance gaps induced by promixinty to
neptune ! there's a pileup of objects. never close enough to gravitationally change their orbits so pluto and rest of them remain in belt undisturbed by neptune
consequences of jupiters size
neptunes influence of KBs structure, delivery of comets to solar system, oort cloud populated with icy objects, delivery of achondrites from vesta, killing dons paving way for human sun turning on ends all planet growth
LAPETUS
nothing like. regular satellite leading side has a run in with some material powder coating icy world. reflectance spectra reveals low albedo. material to. be CC material type
crater saturation
olds worlds surface exposed for long period of time. lots of craters ... adding one destroys one so the relative age is hard to say. cant match cratering populations of outer worlds to moons
what makes object a planet
orbit around sun, massive enough to be rounded by own gravity, gravity pulls into shape , must have cleared neighborhood around orbit---pluto fails this part
jupiter robbed further accretion material by sudden inward migration and scatter of nearby rock material....
overtime, volatiles devlidered from outer solar system to inner SS made wet worlds: earth, mars, venus, moon, mercury
parent bodies of stony iron and iron meteorites are the same as the...
parents bodies of achondrites. objects come from different places... broken or destroyed by other impacts
dark surfaces heated by these high energy photons ...
photons cannot escape nitrogen ice crust so heat builds up in the region between subsurface and ice . melting underside of thick ice crust. liquid they cracks and defects crust ps triton doesnt fit criteria or regular sat so it is an irregular
infant star. in proto-planetary disk is accreting mass at an alarming rate
pressure and temp becomes right in core of protostar to start fusion of H to He energy releases in game rays nd heeat drivers away remaining gas and dust, ending further accretion solid bodies arrive at current size. and shapes in less than 10. mill years
ordinary chondrite
primitive, not to CC's extent. mangled, distorted, parent bodies modified only slightly to heat, can cool quickly when rradioactivee elements are depleted
particles within roche limit tend to be
pulled apart because particles closest to the planet are pulled more strongly toward the planet than particles farther away. they're so close to the planet that their mutual gravity is warped by gravity of the huge planet
chondrules -carbon rich matrix
ratio of elements identical to compoistion of sun minus lightest elements hydrogen and helium. primitive (haven't been altered from og state)...if carbon, nitrogen, organics, and water are present would not be heated or would be lost to space small, primitive, underdiffientiated object
primitive asteroid's water
regulates climate, life, for plate tectonics to function properly . weakens crust at plates boundaries
comet connection
resonances change orbits. interaction with neptune change orbits of objects in KB and push them into planet crossing paths with gas giants... called scattered disk object
composition of a world is important because it
reveals level o f geologic activity on surface
OG material available to build solar systeem
richo mix of elements refractory, volatile, thats reflect relative abundances of all elements in univrese
jupiter rings
rings composition and low albedo prevent direct observation from earth. has no distinct rings but blending of lower and higher density areas. dust grain size, low albedo since rings sit so close in high gravity planet, ring particles are on decaying orbits and stay in orbit for 100-1000 years. less stale ring particles must have constant source to replenish them or else ring disappears and become irregular satellites
saturn
rings made of high albedo water ice.
giant planet satellite types
rings- close to parent planet, found inside roche limnit regular satelittees- beyond roche limit irregular satelittles- found far from parent planet
uranus and neptune similiaries
same cloud composition and gravity but higher concentration of methane. rich clouds. too cold where they live for anything other than methane to condense into clouds. methane ice is blue.
objects take long to accrete art. large distances form sun. based on accretion times we know....
saturn barely and uranus and neptune not accreted. takes objects the size of uranus and neptune much longer than current solar system to form at orbital distances. had MOVED!
all trace gasses combine in....
single atmosphere of ant world fails to make up 1% of total atmosphere with exception of methane in uranus and neptune
ring particle
small small, formation varies, orbits prograde, nearly circle, above equator, close to planet, mostly ice, behaves like regular satellite but very closer to surface, formed beyond snow line
dead worlds
small, heavily cratered worlds made of water ice and organics
irregular satelittes
small/asteroid size, formation=capture, orbits prograde and retrograde, high inclination, from from planet. composition is ice. far beyond snow line. heavily cratered capture- orbit planet in random directions, prograde- orbit in same direction of planet. no apparent rhythm of orbit
planets pink on their axes and air in these systems
so they are subject to coriolis effect
as for mars, it experiences effects of solar wind and
some charged particles get trapped and some aerial along earths magnetic field lines at poles. as spiraling, excite local atmosphere gasses. mostly atomic oxygen, smits energy
planets are natural. consequences of
star formation
the. nice model
starts with gas giant planets. packed tightly within 15 AU from sun. locations are important. late heavy bombardment -- short lived increase. in frequency and size o f impactors pummeling terrestrial planets, forming impact basins on moon and other worlds.
Uranus atmosphere looked at closer...
strange because not heated by sun. orbits sun on its side due to a giant impact so its not heated by the sun at equatorial regions all the time
pluto orbits what
sun and icy object in ring or belt. these small dark objects are hard to find and observe
future
sun will continue to expand and get closer to empty gas tank. bad new for mercury venus earth. will expand to earths orbit ...
Variation of the following properties of Solar System bodies with distance from the Sun:
surface composition density volatility atmospheric composition water, methane, & ammonia (Ices) are only found far from the Sun
geologic activity scales with size
surface dependent, powered by radioactive decay in core ----- duration of geologic activity can last dependent od worlds composition, can be driven by icy worlds because less energy for the same radio active fuel to melt ice better than melting rock if world is powered by radioactive decay of core elements, lacks craters
secondary atmosphere
surface of world must meet and release molecules locked away in sruface
planets cant kick smaller object around without consequences
takes energy. lose orbital energy and orbit shrinks and moves toward sun
methane in atmosphere in surface
temp and pressures are such that liquid methane can exist there,. surface potentially modified by a liquid. these. heavy. hydrocarbons cant stay in the atmosphere for too long ... these molecules rain from titans atmosphere and also evaporate from surface back in to atmosphere in methane cycle. water ice surface solid as rock
How it all ends
the Sun is brightening and evolving 2 Byrs from now Earth will be too hot for complex biology complex life has only existed for the past 0.5 Byrs, the rest of Earth's history has been dominated by single celled organisms small window of time in a Solar System's life for complex life to develop and thrive understand how this connects with finding life on exoplanets
roche limit
the closest distance from the center of a planet that a satellite can approach without being pulled apart by the planet's gravitational field.
ENCELADUS
tiny bit just barely in gravity regime.... so spherical. almost all ice with little rock, smooth young. saturns E ring. large cracks... difference- material venting from cracks in south polar region of satellite , material populates E ring jut outside of roche limit so it cannot survive as a ring there for very long. must be replenished
jupiter and saturn have more in common with stars on some level than planets
transition worlds between terrestrials and gas giants. each worlds atmosphere is for all intents and purposes made of H and He rest of molecules = trace gas
stony iron metoeeirtes come from the...
transition zone. essentially what was the mantle region of the former world
triton v titan
triton lacks hydrocarbons observed in titans atmosphere. has large nitrogen in comparison. provably because of cry volcanoes/ jets of meterial from tritons surface.... tidal heating, chemicals, m and radioactive decay drive this but we gotta look to greenhouse affect
rotation of planets breaks apart the
two hadley cells into many smaller ones. the earths rotation breaks cells into 6... # of cells in atmosphere depends on how big planet is and how fast it rotates
Geologic Activity Scales with Size - except when it doesn't!
understand all sources of geologic activity or heating of worlds Earth/Venus activity = still happening "today" Mars activity = ended "yesterday" Moon/Mercury/Asteroids = ended "a long time ago" Asteroids many were not active very long at all small, potato-shaped objects - strength regime (only one is round) rubble piles Outer worlds made of ice can be geologically active longer but still scales with size among the icy bodies New sources of activity - worlds not powered by radioactive decay of core elements Io & Europa = tidal heating Enceladus = no idea? Triton & Titan = modification from the Sun Giant planets = gravitational contraction
Primary versus Secondary Atmospheres
understand how each secondary atmosphere is different and why melt Rock/Basalt = get water, CO2 & N2 melt Ices = get water, methane & ammonia Venus is not Titan! - atmospheres are different because of different surface compositions greenhouse effect Gas giants have Primary Atmospheres - got big, fast so gravity is large Jupiter and Saturn could retain these atmospheres even very close to the Sun how does this explain hot Jupiter exoplanets?
Crater Density = absolute ages - except when it doesn't!
understand how to read or sketch a crater density diagram and r-plot relative ages lots of craters = old few craters = young crater populations of terrestrial (inner) worlds are similar (small and large impactors) cratering bodies of inner Solar System are from Asteroid Belt outer world cratering populations are different - all small impactors outer icy surfaces cratered by Kuiper Belt objects Moon (surface) is not the same as Calisto (surface) crater record
Samples are Important
understand the different meteorite types and how they relate to asteroids, geologic activity and primitivity lunar rocks reveal ancient history of the Solar System Earth's attic record from samples- record of LHB Reveal 5 stages of Planetary Evolution origin differentiation LHB geologic activity big chill samples make asteroid/meteorite connection primitive meteorites (carbonaceous chondrites) give original Solar Nebula composition not all are primitive - oldest (CCs) give age of the Solar System (~4.5Byrs)
Hydrogen & Helium (& Ices)
vastly outnumber rock & iron in the Solar System (and Universe as a whole) everything heavier than ~Helium on the periodic table is made in the cores of stars!
Exoplanets - there's lots of them!
very close to parent stars and very big - hot Jupiters (true for all detection techniques) - know the biases for each technique probably not typical of all systems, just scratching the surface of systems out there - probably many like ours a natural consequence of star formation - should be almost ubiquitous if this is the case
sulfur rich volcanoes
volatile element. rare of terrestrial world. beyond snow line and can survive there. rich surface surrounding magnesium and iron core
objects surviving close to sun are made of materials. that can withstand radiation, rock and metals, devoid lighter elements pushed beyond snow line when fusion begins.
volatile gasses pushed beyond snow line quickly solidified and were quickly. captured/accreted into icy worlds
reducing the radiation??
water- great radiation sheild water ice rings of saturn lowers radiation to non-lethal level radiation is the biggest challenge engineers and scientists are facing as they face mission to mars
KBO form outside snow line so they are icy HOW TO BECOME COMET:)
when KBOS are tossed inside snow line by jupiter they become comets! as they near heat of sun, icy surfaces change phase as ices quickly sublimate to gasses and lost to space, beautiful tails, new orbit as nears the sun
earth sits in habitable zone around our sun...
which is distance art which temps are warm enough for liquid water to exist on surface
Structure of urbanus and neptunes atmosphere
with have cyclonic storms and high velocity belts and zones. gran's atmospheric structure is less obvious -eeven less obvious than saturn
