Amber Reed Quiz

Chapter 6:
What does the solar system look like?
-The solar system exhibits clear patterns of composition and motion.
-These patterns are far more important and interesting than numbers, names, and
other trivia.
-large bodies in the solar system have orderly motions
-all planets have circular orbits going in same direction in nearly the same plane
-planets fall into two major categories: small,rocky terrestrial planets and
large,hydrogen rich Jovian planets
-swarms of asteroids and comets populate the system. there are vast numbers of
rock asteroids and icy comets are found throughout the solar system, but are
concentrated in three distinct regions.
-several notable exception to these trends stand out. some planets
have unusual axis tilts, unusually large moons, or moons with unusual orbits.
-planets are very tiny compared to distance between them.
Sun:
- over 99.8% of solar system's mass
-made mostly of H/He gas (plasma)
-Converts 4 million tons of mass into energy each second
Mercury:
-Made of metal and rock: large iron core
-Desolate, cratered; long,tall, steep cliffs
-Very hot and very cold: 425 degrees C (day), -170 degrees C (night)
Venus:
-earl identical in size to Earth; surface hidden by clouds
-hellish conditions due to an extreme greenhouse effect
-Even hotter than Mercury:470 degrees C, day and night
Earth:
-An oasis of life
-The only surface liquid water n solar system
-A surprisingly large moon
Mars:-Looks almost Earth-like, but don't go without a spacesuit!
-Giant volcanoes,huge canyon,polar caps and more
-Water flowed n the distant past; could there have been life?
Jupiter:
-Much farther from sun than inner planets
-Mostly H/He; no solid surface
-300 times more massive than Earth
-Many moons,rings
-Jupiter has 4 moons, the Galilean moons
-Io active volcanoes all over
-Europa:possible subsurface ocean
-Ganymede:largest mon in solar system
-Callisto:large, cratered "ice ball"
Saturn:
-Giant and gaseous like Jupiter
-Spectacular rings
-Many moons, including cloudy Titan
-Cassini probe arrived in July 2004 (launched in 1997)
Uranus:
-smaller than Jupiter/Saturn much larger than Earth
-Made of H/He
-at least 27 moons
Neptune:
-similar to Uranus
-at least 13 moons
- Made of H/He
Pluto another dwarf planet
-much smaller than other planets
icy comet like composition
What features of our solar system provide clues to how it
formed?
-The Sun,Planets and large moons generally rotate and orbit in a very organized way
-The planets divide clearly into two groups: terrestrial and jovian
-The solar system contains vast numbers of asteroids and comes and some large
enough to qualify as dwarf planets
-There are some notable exceptions to these general patterns: rotation of
Uranus, earth's large moon and so forth
What theory best explains the features of our solar system?
-The Nebular Theory, which s that our solar system is formed form a giant cloud
of interstellar gas
Where did the solar system come from?
- Elements that formed planets were made in stars and then recycled through
interstellar space
-the cloud of gas that gave birth to our solar system was product of recycling gas
through man generations of stars within our galaxy. this gas consisted of 98%
hydrogen and helium and 2% all other elements
-we can see stars forking in other interstellar gas,clouds lending support in the
nebular theory.
What cause the orderly patterns of motion in our solar system?
-Conservation of Angular momentum-the rotation speed of the cloud form which
tour solar system formed must have increased as the cloud contracted
-Flattening
-collisions between gas and particles
-the spinning cloud flattens as it shrinks
-observation of disks around other stars support the nebular theory
-our solar system began as spinning disk of gas and dust, so orderly motion of this
spinning disk
Why are there two major types of planets?
-planets formed around solid "seeds" that condensed form gas and then grew
through accretion.
-inner solar system, temperatures were so high that only metal an rock could
condense, which explains terrestrial worlds are made of metal and rock.-outer solar system, cold temps allowed ore abundant ices to condense along
with metal and rock.
-icy planetesimals grew large enough for their gravity to draw H and He gas,
forming Jovian planets
Where did astroids and comets come from?
- asteroids are rocky leftover planetesimals of the inner solar system
-comets are icy leftover planetesimals of the outer solar system
How do we explain the existence of our moon and other
exceptions to the rules?
-exceptions came form collisions or close encounters with leftover planetesimals
-our moon is most likely a result of giant impact between Mars-size planetesimals
When did the planets form?
- planets accrete in the solar nebula about 4.55 billion years ago
-radiometric dating of the oldest meteorites
How do we detect planets around other stars?
-Doppler technique: in which doppler shifts reveal the gravitational tug of a
plant(or planets) on a star
-we also can search for transits and eclipses in which a system becomes slightly
dimmer as a planet passes in front of or behind its stars
How so extrasolar planets compare with planets in our solar
system?
-most extrasolar planets have ,asses that suggest  they are jovian
-limited density and composition data support this idea
-many orbits surprisingly close their stars, making them hot Jupiters, and many
have highly elliptical orbits
-a few "super earths"-planets larger than Earth but likely made of metal and rock
Do we need to modify our theory of solar system formation?
-the theory seems to be sound, but we have to modify it to allow for planetary
migration and gravitational encounters