Lecture 10 Our Solar System 2 Flashcards
inner solar system consists of
- inner planets (aka. terrestrial planets), namely Mercury, Venus, Earth and Mars
asteroid belt
outer solar system consist of
- outer planets (aka. gas giants), namely Jupiter, Saturn, Uranus and Neptune
outermost parts of solar system (beyond Neptune) is considered what
a distinct region
e.g., Kuiper belt
characteristics of inner planets (6)
- solid and high density
- made up of rocks and metals
- none have rings (like ones around Saturn)
- small compared to outer planets
- made of cooled igneous (volcanic) rock
- have an iron (Fe) filled core
characteristics of outer planets (5)
- much larger than inner planets
- much lower density (mass/volume) than inner planets
- mostly made up on gases (hence the name gas giants)
- consist primarily of elements hydrogen (H) and helium (H), extremely light gases
- all have rings (not just Saturn, all)
what elements make up the sun and how does it work
LIKE OUTER PLANETS:
- hydrogen (H) and helium (He)
sun has enough gravity to hold onto H and He
where does H and He escape on earth
escape our atmosphere
- while hydrogen still occurs naturally on Earth and is produced through chemical reactions and bacterial activity, hydogen eating atmosphere can escape
what produces He
radioactive decay of elements Uranium (U) and Thorium (Th) in igneous rock produces He
what is the worlds largest producer of He
united states
how is Helium essential
essential in running MRI medical imagining equipment as it serves a vital cooling role
MRI = magnetic resonance imaging
what are outer ring planets rings made of
made of dust and particles
what is special about Saturn’s rings
- they are easy to observe
- made of water ice (H2O) and likely formed when solar system was young
what is the theory of the moons containing ice
they were drawn to saturn (by gravity) and subsequently broke apart, releasing ice dust and particles
- which is how its rings formed
what are jupiters rings made of
very small dust particles
what is neptune’s rings made of
- methane ice (CH4)
- ammonia ice (NH3)
what are Uranus rings made of
rock boulders
(large rocks)
what does the prefix “proto” mean
- first
- foremost
- earliest form of
how old is earth believed to be
4.54 billion years old
how many years ago did our solar system start forming
4.6 billion years ago
what material did our solar system form from
from material in cloud of gas and dust called Solar Nebula
what does solar nebula consist of (elements)
- Hydogen (H)
- Helium (He)
what did gravity do to solar nebula
gravity it caused solar nebula to collapse, spin and flatten into disk shape
what is the flattened disk shape nebula called
protoplanetary disk
how is was a protostar formed
most of solar nebulas material was pulled towards center of protoplanetary disk, forming a protostar
what did protostar become
our Sun
what happened to solar nebulas remaining material
it came together in “clumps”, forming “planetsimals”
what did planetsimals do
they merged with other planetsimals to form protoplanets
what did protoplanets become
planets
- including Earth
what is the name of the protoplanet that became earth
proto-earth
what happened to proto-earth
- proto-earth grew
- heavier elements sank towards the center, forming earths core
- lighter elements moved towards earths surface
what is the movement of heavier elements (especially iron) towards Earths center and lighter elements towards Earths surface called
differentiation (of earth)
what did differentiation led to
the formation of earths layers (inner/outer core, mantle, crust), oceans, atmosphere and eventually continents
what is planetary differentiation
process by which chemical elements of a planetary body accumulate in different areas
ex: heavier iron (Fe) sinks towards center while lighter materials rise upwards
what is theia
- greek goddess of sight, vision and billiance
- supplied gold (Au) , silver (Ag) and gems with their brilliance
- another protoplanet about the size of Mars
what is a hypothesis
a proposed explanation made on asis of limited evidence - a staring point for further investigation
what is the giant-impact hypothesis
- first proposed by canadian geologist Reginald Daly in 1946
- approximately 4.5 billion years ago, theia, a protoplanet, collided with protoearth, releasing material from both into space
- some released material came together and forme our moon
who is selene
daughter of goddess theia
- selene is goddess and personification of our moon
what is the legend in northwest communities
Raven stole light in form of sun, moon and stars from old chief who kept it locked away in a box
after Raven escaped with box through smoke hole of chiefs home, he places sun, moon and stars in sky for al beings to enjoy
originally Raven had white feathers, but flying though smoke hole made Raven feathers black
how has our moon inspired us
has inspired us since the beginning of time
- poems
- philosophical texts
- songs
- artwork
etc
what is the diameter of the moon
3475 km
what is the difference in size between earth and moon
earths diameter = 12760 km
moon is 27% (or 1/4) the size of earth
what is the distance from Earth to the Moon
384 400 km
what is the shape of the path of the moon around Earth
slightly elliptical (ellipse shape)
- earth is not at the center of moons orbit
- thus, distance to moon change as it orbits our planets
