Amber Reed

Chapter1:
what is our place in the universe:
-our "cosmic address"
-earth is the third rock from the sun
-Star: a large glowing ball of gas that makes heat and light by nuclear fusion (Sun)
-PLanet: a large object that orbits a star, and shines by reflected light. (may be
rocky,icy or gaseous) ex: Mars or Uranus
-Moon(satellite) a object that orbits a planet
-Asteroid: small and rocky object that orbits stars (Mathilde)
-Comet: small and icy object thats orbits stars
-Nebula: a interstellar cloud of ga/or dust (there is on in Orion the constellation)
-Galaxy: great island of stars in space, all held together by gravity and orbiting a
common center (a black hole is in the middle of a galaxy) ex:M31, the great
galaxy in the Andromeda
-Universe: the sum of the total all the matter and energy, everything in and
between all galaxies
-Earth is a part of the solar system, which is the Milky Way which is the member
of the local Group of Galaxies in the Local Super Cluster
How did we come to be:
-Birth of the Universe was 13,700,000,000 years ago
-Hot and dense Big Bang began with this expansion
-as the universe continues to expand,smaller scales of gravity pulls matter
together to make galaxies
-galaxies as cosmic recycling plants. the early universe contained two chemicals:
hydrogen and helium All other elements were made by stars or were recycled
from one generation to generation from galaxy to the next
-many generations of stars have lived and died in Milky Way
-by the time solar system was born, 4 1/2 billion years ago, about 2% of the
original hydrogen and helium had been converted into heavier elements.
-
How can we know what the universe was like in the past:
-light travels at a finite seed (300,00 km/s)
-we see objects as they were in the past : The farther away we look in the
distance, the further back we look in the time.
-moon is 1 second of light travel time from earth
-sun is 8minutes away in light travel from earth
-Sirius is 8 years of light travel from earth
-Andromeda Galaxy is 2.5 million years of light travel form earth
-light year:the distance light can travel in 1 year...
approximately 10 trillion kilometers (6 trillion miles)
-a great distance, we can see how things were, of course this was when the
universe was much younger
Can we see the entire universe:
-no because there may be things that are farther away that the light had not
touched
-why can't we see a galaxy 15 billion light years away?
a. No galaxies exist at such a great distance
b. Galaxies may exist at this distance, but their light would be too faint for our
telescopes to see
c. Looking 15 billion light years away means looking to a time a time befor the
universe existed
answer C
1.2 The scale of the Universe
How big Earth compared to our solar system?
-How big is the Earth on this scale ? (
a. an atom
b.a tip of a ball point pen
c. marble
d. a golf ball
Answer B
How faraway are the stars?
-In our 1to 10 billion scale, its just a few minutes walk to pluto?
how far would u have to ealk to reach Alpha Centauri? a. 1 mile
b. 10 miles
c. 100 miles
d. The distance across the Unite States (2500) miles
answer D
Suppose you tied to count the more than 100 billion stars in our galaxy, at rate of
one per second..
How long would it take you?
a. a few weeks
b. a few months
c. a few years
d. a few thousand years
Answer D
How big is the Milky Way Galaxy?
-is one of the 100 billion galaxies
-it would take more than 3000 ears t count the stars in the milk way at a rate of
one per second. the Milky Way way galaxy is about 100,000 light years across
How big is the Universe?
-it has many stars as grains of (dry)sand on all Earth's beaches
-100 billion glaxies
-14 billion light years in radius
How do our lifetimes compare to the age of the universe?
-The cosmic Calendar; a scale on which we compress the history of th universe
in 1 year
1.3 Spaceship Earth
How is Earth moving in the solar system?
-We are not "sitting still"
-we are moving in several ways, and at different speeds
-earth rotates on its axis once every day
-the farther you go south, the bigger the distance you have to rotate because
earth is a sphere
-our sun moves relatively to the other stars in the local solar neighborhood
-typical speed is more than 70,000 km/hr
-stars are so far that they cannot easily notices their motion
-orbits the galaxy every 230 million years
How is our solar system moving in the Milky Way Galaxy?
-most of the light comes from the disk and bulge...but most of the mass is in its
halo
How do galaxies move within the universe?
-galaxies are carrie along with the expansion of the universe.
-the more distant between galaxies the faster they move
Are we ever sitting still?
NO!!!!!
Chapter 2: Discovering the Universe for Yourself
2.1 Patterns in the night sky
what does the universe look like from the earth?
-with the naked eyes, we can see more than 2000 stars as well as the Milky Way
-ancients thought someone spilled milk in the sky, thats how it got its name
-a constellations is a region of the sky
-eighty eight constellations are in the entire sky
The brightest of stars in a constellation..
a. all belong to th same star cluster
b. all lie about the same distance form the earth
c.may actually be quite far away from each other
answer C
-celestial sphere: stars at different distances appear to be on the same celestial
sphere
-the ecliptic s the Sun's apparent path through the celestial sphere
-88 constellations cover the celestial sphere
-milk way is a band if the light that makes a circle around the celestial sphere
-local sky: an object's altitude(above horizon) and direction (along horizon)
specify its location in you local sky
-zenith:the point directly overhead
-horizon:all points 90 degrees away form Zenith
-meridian :line passing through zenith
-full circle = 360 degrees
-1 degree= 60 arcminutes
-1 arcminutes=60 arcseconds
the angular size of your finger at arms lengths is about 1 degree. how many
arcseconds is this?
a 60 arc seconds
b 600 arcseconds
c 60x60=3600 arcseconds
answer C
Why do stars rise and set?
Why do the constellations we see depend on the latitude and time of year?