Gravity, The Universe, Galaxies Flashcards
the linear correlation between the rate of the expansion of the universe and distance
the hubble law
The idea that the sun, not the earth, was the center of the universe.
Copernican hypothesis
the night sky ___________ depending on where you are on earth
changes
The point directly above you
Zenith
The point below you
Nadir
constellations that never rise or set
circumpolar constellations
big bear and little bear
Ursa Major and Minor
line from north to south
Meridian
angle of a star above your horizon
altitude
An apparent shift in the position of an object when viewed from different locations
Parallax
The death of a large star by explosion
Supernova
The theory that the universe originated in a huge explosion that released all matter and energy.
The Big Bang Theory
radiation uniformly detected from every direction in space; considered a remnant of the big bang
Cosmic Background Radiation
how long does it take a zodiac sign to change
a month
Which constellation looks like a teapot?
Sagittarius
the force that attracts a body toward the center of the earth, or toward any other physical body having mass.
Gravity
the orbits of the planets around the sun are ellipses with the sun at one focus
Keplers 1st law
a line from a planet to the sun sweeps over equal areas in equal intervals of time
Keplers 2nd law
the two quantities, orbital period and semi-major axis, are related
Keplers 3rd law
what is issac newton known for?
Telescopes, Calculus and Physics
the force of gravity between two objects depends on _____ and _____
mass and seperation
Low Earth Orbit
LEO
Geostationary Orbit
GEO
Sub-Orbit
craft does not complete orbit
a set of gravitationally stable points related to the Earth, Sun, Moon’s mutual gravity
Lagrange points
the speed needed to escape an object’s gravitational pull
Escape Velocity
Why are astronauts weightless?
They are in free fall
the sun ______________ as a result of the gravitational pulls of the orbits of the planets
wobbles
shapes of orbits
circle, ellipse, parabola, hyperbola
The gravitational attraction between masses is a result of the nearby masses; gravity has waves
General Relativity
Gravitational waves are
ripples in the fabric of space-time
imaginary line in the sky representing the projection of the Earth’s equator on to the celestial sphere
celestial equator
imaginary points in the sky which is the projection of the north/south pole on the night sky
North and South Celestial Poles
circle of ground around you
Horizion
angle of star NE from N-360 degrees all around
Azimuth
the motion of a body around a point outside the body
Revolution
a great circle on the celestial sphere representing the sun’s apparent path during the year, so called because lunar and solar eclipses can occur only when the moon crosses it.
Ecliptic
The brightness of an object depends on — and —-
distance and size
the ___________ the object, the ____________ it will be
larger; brighter
the absorption lines in a galaxy’s spectrum will be shifted toward redder wavelength if the galaxy is moving away from us
redshift
The succession of methods by which astronomers determine the distances to celestial objects
Cosmic Distance Ladder
T/F: There is a center to the expansion of the universe
false
What universe is it when parallel lines converge?
Closed
What universe is it when parallel lines diverge
open
What universe is it when parallel lines stay parallel to each other?
flat
what shape is our universe?
flat
what color did our universe use to be?
orange
flat, young stars are
disk
puffy center with older stars
bulge (nucleus)
spherical region surrounding galaxy with globular clusters
halo
small spherical clusters of the oldest stars
globular cluster
what creates seasons?
the amount of sunlight
what is the difference in the northern and southern hemisphere
the sun climbs towards the south of the sky in the northern hemisphere
what consellation looks like a hunter?
orion
what constellation looks like a bull?
taurus
The motion of the Sun through the Zodiac Constellations throughout the year is caused by…
the earths revolution
