Astronomy Ch 1-4
How many stars are in the Milky way
100Bill
Modern telescopes see galaxies from
10bill light years away
Age of universe
10billion to 16billion
Where is our solar system located within the Milky Way
2/3 way from the center of the galaxy to the outskirts of the galactic disk plate
If mass is 60kg on earth, what would the mass of moon be
60kg
Evidence that the earths orbit is not a perfectly circular
Angular size changes and the seasons are perfect length
The meaning too the universe expanding
Average distance are increasing between galaxies
Which scientist played a role in overturning the accent idea of an earth-centerd universe and when?
Copemicus, Kepler, and Galileo; 400 years ago
Why didn't Copernicus Sun-centered model lead to a better prediction of Ptolemaic Model
Copernicus used perfect circles for the orbits of the planet
Why is there a leap year
Earth year being a non integer number of earth days
allowed shapes for orbits under force of gravity
Ellipses, parabolas, and hyperbolas
Discovered what we now call Newtons first law of motion
Galileo
Who discovered Jupiter's moons
Galileo
The sun is mainly made of
Hydrogen and helium
Discovered orbits of planets are ellipses
Kepler
an object is moving in a straight line at 50mi/hr. According to Newtons laws of motion the object will
Move in the same way until acted upon by a force
Which one follows Keplers 3rd Law
Venus orbits the sun at a slower average speed than mercury
addressing in correct order
Y,E,SS,MW,LG,LS
Keplers 3rd law p2=a3 means
all the above
why is polaris special
appears near the north celestial pole
What is an astronomical unit?
average distance from earth to sun
How did eratosthenes estimate the size of Earth in 240 B.C
comparing the max altitude of sun in two cities at different latitudes
Book of a famous person published in 1543, suggesting that earth and other planets orbit the sun
copernicus
Why were ancient people unable to detect stellar parallax
didn't have ability to measure small angles
Moon:
distance from the earth varies during orbit
Driving at a constant speed but not at a constant velocity
driving around in a circle at exactly 100km/hr
radiative energy
energy carried by light
conserved quantity
energy, angular momentum, and momentum
When would you feel weightless
falling from a roof
How many stars can you see to the naked eye
few thounsand
describe the meridian in your sky
half circle extending from horizon due north, through your zenith, to horizontal due south
Universal law of gravitation the force due to gravity is
inversely proportional to the square of the distance between objects
describing position on earth surface
latitude and longitude
momentum
mass time velocity
quantities of angular momentum
mass, velocity, and radius`
Why was ptolemy important
modeled the solar system that made predictions for planetary positions
Why do we see the same face of the moon at all times
moons rotational and orbital periods are equal
lunar phase where tides are more pronounced
new and full moon
Example of why Keplers second law is true
planets angular momentum musted be conserved as it moves around an orbit
Constellation
region of the celestial sphere
Seven days of the week are based on
seven naked eye objects that appear among the constellations
Einstiens equation E-mc2 states that
small amount of mass can be turned into a large amount of energy
circumpolar star
star that always remans above your horizon
ecliptic
suns apparent path along the celestial sphere
Origin of ocean tides
the difference in force gravity exerted by moons across sphere of the earth
How are galaxies important to our existence
the recycle from other galaxies
cosmo
total of all matter and energy
What do stonehenge, templo mayor, sun dagger, and big horn medicine wheel have in common
used by ancient people for astronomical observations
inverse square law: if you double the distance of two large masses the gravitational force between
weaken by 4