Ch. 22 solar system

nebular theory

• explains formation of solar system

• sun and planets formed from solar nebula (rotating cloud of gas and dust(

• solar neb contracted/formed hot protosun

• planetesimals formed

• planetesimals becme protoplanets

terrestrial / earth like planets

• mercury, venus, earth, mars

• small, dense, rocky

• large cores of iron and nickel

• low escape velocities

jovial / jupiter like planets

• jupiter, saturn, uranus, neptune

• large, low, gaseous

• thick atmosphers of hydrogen, helium, methane, ammonia

• high escape velocities

impact craters

• collisions with massive objects

• common in early formation of solar system

• have central peak and ejecta lands in or near center

maria - lunar surface

• dark regions

• smooth lowlands

• originated from asteroid impacts and basaltic lava flooding surface

highlands - lunar surface

• bring, densely cratered regions

• make up back side of moon

• older than maria

lunar regolith

• layer of gray, unconsolidated debris 2-20 m thick

• igneous rock, breccia, glass beads and lunar dust from few billion years of meteoric bombardment

mercury

• 1st planet from sun

• no atmosphere

• cratered highlands

• vast and smooth

• dense

• revolves quick, rotates slow

• low escape velocity

venus

• 2nd planet from sun

• 900F

• similar to earth in size and density

• thick clouds

  • no visible light

  • 97% carbon dioxide

  • pressure 90x earth

  • rains sulfuric acid

• surface mapped by radar satellites

• rotates opposite direction around sun

mars

• 4th planet - red planet

• 1% as dense as earth

• mostly co2

• -193F

• polar caps of frozen water and thin layer of frozen co2

• dust storms of 170mph

• large volcanos and canyons

• tectonically dead

• rock outcrops and crossbedding (suggests sand dunes)

• “stream drainage” patterns

jupiter

• 5th planet

• largest planet

• banded appearance generated by wind

• great red spot

  • southern hemis

  • counterclockwise rotating - cyclonic storm

• 28 moons

  • 4 largest are lo, eurpa, ganymede, callisto

  • discovered by galileo

saturn

• 6th planet

• bands of clouds and storms like jupiter

• intense lightening

• 93% hydrogen and 3% helium by volume

• rings

  • small particles of water ice and rocky debris that orbit planet (moonlets)

  • debris possibly ejected from moons

  • discovered by galileo in 1610

uranus

• 7th planet

• twins with neptune

• rotates on its side

• rings

• large moons w/ varied terrains

neptune

• 8th planet

• dynamic atmosphere

• one of windiest places in solar system

• greak dark spot

• white, cirrus-like clouds above main cloud deck

• triton is largest stellite and has ice lavas

asteroids

• leftover plantesimals from formation of solar system

• most like between mars and jupiter in asteroid belt

• small bodies - largest (ceres) is 620 miles in diameter

• some have eccentric orbits

comets

• large dirty snowballs

• made of frozen gases and rocky and metallic materials

• frozen gases vaorize when near sun

  • produces glowing head caled coma

  • some develop tail that points away from sun bc radiation pressure and solar wind

meteoroids

meteors but in space

meteors

• meteoroids when they enter earth’s atmospher

• shower occurs when earth encounters sawm of meteoroids associated w/ a comet’s path

meteorites

• when found on earth

• classified by composition

  • stony-irons - mixtures

  • carbonaceous chondrites

    • rare and made of simple amino acids and other organic material

dwarf planets

• includes pluto

• not the only objects occupy their area of space

• in kuiper belt - brand of icy objects found beyond orbit of neptune

pluto

• not naturally visible

• discovered in 1930

• dwarf planet

• moon (charon) discovered in 1978

• -210C