Astronomy quiz

Constellation

a region of the sky

not scientfically significant

1603

system for naming stars with greek letters

magnitude

refers to brightness

0 is the brightest 6 is the dimmest

the larger the magnitude the dimmer the star

Star trails

shows the circular motion of the sky

everything rises in the east and sets in the west

stars remain in fixed postions

Archaeastronomy

study of how ancients viewed the universe

Many cultures around the world
observed the sky and marked important
alignments.

Ancient structures

stonehenge, carcol, mayan city, Tulum Mexico

Astronomy of greece

Derived from previous civilizations ( babylon and Egypt)

Greek astronomy is better known as written documents

First ones actually tried to understand the universe as far as we know

Pythagoras

noticed mathmatical patterns in nature

Thales of Miletus

Believed humans could understand the universe and how it works

Plato

believed we see a distorted shadow of perfect form

believed the perfect form was a circle

Aristotle

divided universe into two parts heaven and earth

Argued Earth not moving because he
saw no parallax

argued that
if the Earth were
moving we would
see the star
positions changing

Parallax

Change in postion in an object due to change in location of the observer

Ptolmaeus

explained retrograde motion by a system of wheels withing wheels

Eratosthenes

Measured the circumference of the earth 2500 years ago

Middle ages (europe)

Ancient greek writing perserved by Islamic nations for centuries

Copernicus

came up with Heliocentric model

Galileo Galilei

based on observations with a telescope

Moon was not perfect
 Milky Way made up of
stars
 Jupiter had moons
 The heavens weren’t so
perfect anymore
 Inquisition

waxing

describes increasing amounts of visible light reflecting off the moon

waning

describes decreasing amounts of visible light reflecting off the moon

Crescent

describes the moon when less than half of the visible moon surface is illuminated

Gibbous

more than half of the visible moon surface is illuminated

Umbra

full shadow

penumbra

partial shadow

First quarter

the waxing half moon that appears when the moon has traveled one quarter of its orbit around the earth

Third/last quarter

the waning half moon that appears when the moon has traveled three quarters of tis orbit around the earth

why does the moon shine?

reflects light

Luminous

produces its on light

ex. the sun

Illuminated

lit up by something

ex. sun lights up the moon

IMPORTANT

The full moon rises at sunset

the moon orbit is not a perfect circle

Solar eclipse

sun being eclipsed

Lunar eclipse

moon being eclipsed

Path of totality

moons shadow going across the earth

Celestial sphere

a giant sphere extending from the earth which celestial objects reside. describing what the sky looks like as we see it

Parts of a celestial sphere

north south east and west on the horizion. the north and south celestial poles and celestial equator are directly above earth’s counterparts.

Zenith

directly overhead of observer

Nadir

directly below observer

ecliptic

the apparent motion of the sun and planets across the sky

Right ascension

east and west

declination

north and south

telescope

can use equitorial mount

equinox

when the ecliptic and celestial equator intersect the sun crosses the celestial equator

solstice

when the sun is furthest from the celestial equator highest or lowest point in the sky

analemma

when you take a picture of the sun everyday for a year it traces out a certain shap the ends are solstices and intersection is equinox

altitude of the sun

further south in winter and further north in summer

angle of the sun

in the winter we are tilted away from the sun more than we are in the summer

axial tilt

tilt from the sun which causes the seasons

Tides

cyclic rise and fall of sea levels

caused by the combined effect of gravitation forces exerted by the moon, sun, and rotation of the earth

high tide

when water levels are highest

low tide

when water levels are the lowest

tidal range

the difference in height between high and low tide

typical tidal ranges in the open ocean are about 2 feet

coastal tidal ranges can greatly vary from 0 to 52 feet

Gravity and Inertia

work together to create the two major tidal bulges on earth

Inertia

the tendency of moving objects to continue moving in a straight line

Spring tides

occur during new and full moons

they occur twice a month

greatest tidal range

higher than normal high tides and lower than normal tides

sun moon and earth are aligned

when sun earth and moon are aligned the combined gravitational pull creates larger tidal bulges and lower low tides

Neap tides

occur during first and third quarter moon

occur twice a month

little tidal range

sun moon and earth are located at right angles to eachother

hightides are a little lower and low tides are a little higher than average

Semidiurnal tides

most coastal areas experience semidiurnal tides

two equal high tides and two equal low tides

Diurnal tides

only one high tide and one low tide per day

Mixed semidiurnal tides

two unequal hightides and two unequal low tides

diurnal inequality

the difference in height between high or low tides

ptolemaic system

considered the standard model of the universe until the copernican revolution