Solar System Leftovers

Solar System Leftovers : 

Solar System Leftovers Solar System Astronomy Chapter 12

Solar System Leftovers : 

Solar System Leftovers …really asteroids, meteorites, comets, and other debris… …still Chapter 12

Debris : 

Debris Asteroids small, irregular bodies most are rock or metal most orbit between Mars and Jupiter some can cross Earth’s orbit model conditions in the early Solar System (?)

Debris : 

Debris Meteorites pieces of asteroids that have fallen to Earth In space it is called a meteoroid While passing through the atmosphere, it is a meteor If it hits, it is a meteorite Different types: reflect different physical conditions during formation

Debris : 

Debris Meteorites Different types: Stony Like Earth rocks Come are carbonaceous Iron High concentrations of metals Stony-iron Can date meteorites to age of Solar System HOW?

Debris : 

Debris Meteorites from microscopic dust to a few centimeters About 2 meteorites large enough to produce visible impacts strike the Earth every day Statistically, one meteorite is expected to strike a building somewhere on Earth every 16 months typically impact atmosphere 10-30 km/s ~30 times faster than a rifle bullet

Primitive or Processed? : 

Primitive or Processed? Larger asteroids & planets were hot/molten during formation Leads to differentiation Heavy minerals sink Some asteroids were part of differentiated bodies So asteroids collide & fragment

Asteroids : 

Asteroids Orbits Most between Mars & Jupiter Orbits are prograde Orbits are not highly inclined from plane of Solar System Orbits are not highly eccentric (circular or nearly so) Though many NEAs have orbits crossing Earth’s

Asteroids : 

Asteroids Orbits

Asteroids : 

Asteroids Orbits

Asteroids : 

Asteroids Orbits Kirkwood Gaps

Asteroids : 

Asteroids Orbits

Asteroids : 

Asteroids Orbits

Beyond the Asteroid Belt : 

Beyond the Asteroid Belt

Trans-Neptunian Objects (TNO) : 

Trans-Neptunian Objects (TNO)

Comets : 

Comets Big, dirty snowballs Nucleus is ice/rock mix ~5 km Active near Sun Nucleus Coma Ion tail Dust tail Comet tails point away from Sun

Comets : 

Comets Big, dirty snowballs Nucleus is ice/rock mix ~5 km Active near Sun Nucleus Coma Ion tail Dust tail Comet tails point away from Sun

Comets : 

Comets Big, dirty snowballs Nucleus is ice/rock mix ~5 km Active near Sun Nucleus Coma Ion tail Dust tail Comet tails point away from Sun

Comets : 

Comets Big, dirty snowballs Nucleus is ice/rock mix ~5 km Active near Sun Nucleus Coma Ion tail Dust tail Comet tails point away from Sun Comet Hale-Bopp, 1997

Comets : 

Comets fragmentation Moon Callisto Shoemaker-Levy 9

Comets : 

Comets Geology Comet nuclei contain ices of water, carbon dioxide, methane, ammonia, etc these should have condensed from outer solar nebula those compounds sublime (transition from solid directly to gas phase) as comets approach sun Densities of comet nuclei: ~0.1–0.25 g/cm3 not solid ice balls — fluffy material, significant amounts of empty space

Comets : 

Comets Origins Most believed from Oort Cloud 10-100k AU Some from Kuiper Belt 30-50 AU Comet Hale-Bopp, 1997

Impacts : 

Impacts

Impacts : 

Impacts Chixulub

Impacts : 

Impacts Chixulub

Impacts : 

Impacts Chixulub Mayan for “tail of the devil” now buried beneath a kilometer-thick sequence of sediments diameter of 145 to 180 km object that hit ~10 km diameter impact ~6 million times more energetic than 1980 Mt St Helens impact ejected rock from several km beneath the surface of the Earth