Assignment 1 Flashcards
what are examples of active and dynamic surface
venus, earth, europa and lo (moons of Jupiter0, titan (a moon of Saturn)
what are inactive surfaces
mercury, earths moon, Callisto and Ganymede (moon of Jupiter)
is mars inactive or active
in between
are active or inactive surfaces older
inactive
do active or inactive surfaces have more craters
inactive, active surfaces move and erase craters
difference between volcanic creators and lunar impact craters
lunar impact crater is much flatter
how fast are impacting bodies
17 to 70 kilometers per second
why are craters circular
1) meteor prior to impact has lots of kinetic energy
2) upon impact, converted to other forms of energy
3) if impact energy > binding forces of meteor = explosion generation circular shockwave
what are the two types of creators
- simple impact crater
- complex impact crater
what are simple impact creators
most common type, circular bowl like with raised rim
what are complex impact creators
- peak in the middle of the circle
- formed by larger impact bodies
- surrounding by rings of elevated Terrances
- hit really hard, ground rises back up
what are rays around craters
ejected material from impact
how does cross cutting highlight age
if one feature overprints another, that feature must be younger than the feature it cross cuts
what is mare
lava flows that covered older crust
when did the Maria rocks on the moon date to
3.8 GA
when did the highland rocks on the moon date to
4.2 GA
what is the late heavy bombardment
increased impacts between 4.1 and 3.8 GA
what does the nice model suggest
outer planets initially formed closer to the sun
gravitational effects between them caused them to move outwards
caused material from outer solar system to be scattered inward
when was the vredefort crater
2 billion years ago
how big is the vredefort astroid
10 km diameter
where was the vredefort crater
southwest of Johannesburg
how big is the vredefort crater
40 km deep and 100km wide
how big was the vredefort crater on impact
somewhere between 180 to 300km wide
how big is vredefort dome
90 km across
