Test 1 Flashcards
projection of Earth’s equator onto the sky
celestial equator
annual path of sun in the sky
ecliptic
points directly above the observer
zenith
opposite of zenith (directly below)
nadir
latitude where the Sun appears at zenith at noon on first day of SUMMER
tropic of cancer
where the sun passes through zenith on first day of WINTER
tropic of capricorn
where the sun’s path crosses celestial equator, when day and night are ~ equal length
equinox
earth centered
geocentric
sun centered
heliocentric
stars & earth move ____ to _____
east to west
first day of summer, around June 21st
summer solstice
circle running from one pole to the other, passes thru zenith
meridian
meridian passing thru Greenwich, England
prime meridian
first day of winter, around Dec 21st
winter solstice
where the sun’s path crosses the celestial equator
vernal equinox
the sun rises when it reaches the _____ _______, around March 20th
vernal equinox
the sun sets when it reaches the ____ _______
autumnal equinox
measured in degrees north & south (latitude)
declination
measured in time, east to west (longitude)
right ascension
number of degrees from north
azimuth
angular elevation up to 90°
altitude
where the dome meets the earth
horizon
______ discovered retrograde motion of planets and created a geometric representation that predicted positions of the planets
Ptolemy
plot or graph in figure eight shape that shows the position of the sun at a given time
analemma
the analemma is also known as the ______ __ ____
equation of time
______ discovered that Jupiter has revolving moons which casted doubt on geocentrism
Galileo
_________ discovered the first fairly accurate determination of Earth’s diameter
Eratosthenes
____ created a record of the positions of the sun, moon, and planets based on the work of Ptolemy
Brahe
______ found a theory about planetary motion by using Brahe’s data, assistant to Brahe
Kepler
____’s FIRST law is that the planets’ orbits are in the shape of an ellipse
Kepler’s
planets speed up when they come closer to the sun and slow down when they move away from the sun
Kepler’s SECOND law
the amount of time a planet takes to orbit the sun is directly related to how far the planet is from the sun
Kepler’s THIRD law
______ discovered that all celestial bodies had an attraction to each other called gravity
Newton
the _____ _______ is when the sun is at the highest point in the sky
summer solstice
measuring relative to the SUN
solar
measuring relative to the STARS
sidereal
solar days are longer than sidereal days by __ minutes
4
Earth’s axis of rotation wobbles in space and makes a complete revolution every 25,800 years
precession
_________ formulated a model of the universe with the SUN at the center
Copernicus
