Transcript Universe and Solar System

FORMATION OF THE SOLAR SYSTEM
Ch. 16…Pg. 552
Formation of the Solar System
 What Galaxy are we in?
 Milky Way
 Alpha Centauri: Star system closest to us
 Nebular Hypothesis: States that our solar system formed
from Solar Nebula: A thick could of dust that began to fold
in it’s own gravity into a rotating disk-shaped cloud. It’s
gravity pulled heavier elements into the center, creating a
protosun.
Section 1: Observing the Solar
System
Pg. 354
Vocab you need:
 Geocentric: Earth is the center of the revolving planets and
star
 Greeks once believed in this formation
 Heliocentric: earth and other planets revolve around the sun
 What is the shape of the revolution? Elipse
 Moon: Natural satellite that revolves around a planet
The Sun
Pg. 560
 Sun is a ball of gas---not solid like the earth
 Core:
 Central region
 Nuclear fusion(Hydrogen atoms joining together) happens here
 Can only happen under high temps
 Radiation Zone: Tightly packed gas where electromagnetic
radiation is emitted from (Comes from)
 Convection Zone: Outer layer.
 Forms a convection current layer where hot gases rise, cool,
then sink back down.
Atmosphere of the sun
 Photosphere: Gives off visible light
 Chromosphere: Middle layer that gives the sun it’s reddish
glow
 Corona: Outer layer that extends out in to solar winds
(Charged particles that travel through space)
Planets
 Terrestrial Planets: Inner Planets
 Mercury, Venus, Earth, Mars
 Small, dense, rocky surfaces
 Jovian Planets: (Gas Giants)Outer Planets
 Jupiter, Saturn, Uranus, Neptune
 Large, many moons, rings (small particles of ice & rock)
 Pluto: Solid surface, denser than out planets---smaller than
earth’s moon
 Now considered a dwarf planet
Comets, Asteroids, and Meteors
 Comets: loose collection of ice, dust, and rock whose orbits are long
narrow ellipses
 Coma: atmosphere that surrounds the head of the comet
 Nucleus: The inner core of the head
 Gas Tail: Points away from the sun
 Asteroids: Rocky objects too small to be considered planets
 Orbit the sun—mostly found between Mars & Jupiter (Asteroid Belt)
 Meteoroid: Chunk of rock or dust in space that has broken off of
comets or asteroids.
 When they enter Earth’s atmosphere, they burn, producing a tail (Shooting
Star)---Meteor
 Meteor shower happens when a comet passes earth, leaving a dust trail to fall
into the atmosphere…
Chapter 17: Stars, Galaxiess and
the Universe
Pg. 598
Stars
 Form imaginary patterns called Constellations
 Classified by
 Color: Red or Blue
 Temperature: Red=Cool, Blue=Hot
 Size: Sun is medium…most are smaller than that, white dwarfs
are about the size of the earth
 Made of: Hydrogen and Helium
 Brightness: Depends on Size and Temperature
 Apparent Brightness: Seen from Earth
 Absolute Brightness: Brightness it would have at a certain
distance from earth.
Measuring
 Light Year: Distance light travels in one year---9.5 Million
million Kilometers
 Parallax: Change in position of an object when viewed from
different places
 Scientists use the Hertzsprung-russel diagram to classify
stars.
 The Main Sequence is a diagonal area where most stars exist.
Lives of Stars
 Born a Nebula (Large cloud of Gass)
 Contracts to form a protostar
 Length of life depends on Mass
Death of A Star
 White Dwarf: Blue white core left behind when a star burns
out.
 Supernova: Explosion that occurs when a star runs out of
fuel
 Neutron Stars: Remains of high mass stars where particles
are left.
 Black Holes: Object with gravity so high that light can’t even
escape…pulls gas inward into a dense ball that can’t be
penetrated
Star Systems
 Binary Stars: Have 2 stars
 Eclipsing Binaries: Systems where one star blocks the other
star
 Star Clusters: Larger groups of stars
 Open Clusters: Disorganized appearance
 Globular Clusters: Older clusters that are round and densely
packed
Galaxies
 Groups of stars or star systems
 Spiral Galaxies: Spiral outward like a pinwheel
 Elliptical Galaxies: Round, flat balls
 Irregular Galaxies: No regular shape..smaller than other
types
 Quasars: Objects that are more than 10 billion light years
away
The Milky Way
 Our Galaxy
 Spiral Galaxy
 We are in one of the spiral arms
Scale of the Universe
 Universe: Space and everything that is in it.
 Scientific notation: Uses powers of 10 to express large
numbers---Scientists use it to explain distances in space due
to their large size
 Look at pg. 626
Universe Formation
 Big Bang: A tiny ball of space particles exploded. The ball
was very hot and dense. The explosion caused the particles
to spread out, cool, and expand.
 If this is true, then the galaxy is still expanding today…
 Hubble’s Law: The farther away a galaxy is, the faster it is
moving away from us
 Cosmic Background Radiation: Leftover energy from the big
bang that creates a glow in our universe
Formation of the Solar System
 Solar Nebula: Large cloud of gas and dust that formed our
solar system.
 Gravity pulled it together and pulled things toward it, causign
the sun to be born.
 Planetesimals: Small, planet like bodies that formed the
building blocks of planets.
 Inner planets: Space items pulled into sun’s gravity…water
evaporated…
 Outer Planets: Cooler, gasses were able to increase the size of
these planets.
Other Characteristics
 New technology and observations are leading to new
discoveries every day.
 Dark Matter: Does not give off light or radiation and is hard
to investigate.
 Dark Energy: A force that is causing the expansion of the
universe to accelerate (Speed up).