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Earth Science chapter 2 unit 1 Astronomy and Space NYS

3 476 km is the diameter of the
the Moon's average density
3.3 g/cm3
gravity of Moon is
1/6 of Earth's
The Moon's interior structure is similar to earth's and has
The Moon turns on its axis
per revolution around Earth
T/F: the same side of the moon always faces earth
lighter areas of the Moon
lunar highlands
darker areas of the moon are
great basins and plains
collision theory
theory that states that the Moon was formed when a large, mars-sized object struck Earth about 4.6 billion years ago
about 1/6 of earth's mas was shot out into
Earth's orbit
Moon's formation was followed be a period of
meteorite bombardment
volcanic activity formed
the moon is estimated to have been formed about
4.6 bya
The age of the Moon is dtermined by
dating radioactive elements found in Moon rocks
lunar maria
large planes with hugh circular craters
the Moon is essentially the
8th continent
Lunar maria rocks resemble
bosalts from volcanic flows in Hawaii
"mas contractions"
lunar highlands
rocks are lighter- reflect more sunlight
lunar mountain ranges are found at the edges of the
Anorthoclase gabbro
rough, crystalline igneous rocks
lunar breccias
made of angular fragments and natural glass cemented together
indentations on the moons surface caused by meteorite impacts
craters were formed on the moon during
the bombardment period in the solar systems early history
craters shape
roughly circular with raised rims
rough streaks radiating away from craters
lunar soil id made up of
smaller rock pieces, dust, and natural glass
loose, rocky materials
regolith color
T/F:The moon has no organic matierial but has water
lunar soil thickness
1-20 cm
moons orbit
revolves west to east around Earth in a elliptical orbit
moon's period of revolution
27.3 days
moon's average distance from earth
384 000km
when the moon is closest to the moon
when the moon is farthest from earth
moon's orbital plane
5 degree difference from earths orbit
moon rises in the
moon sets in the
the moon rises at a different time
each day
the moon moves 13 degrees in its orbit every day, causing the moonrise to be
50 minutes later each day
1 lunar cycle is equal to
29.5 days
from new moon -> full moon
from full moon -> new moon
phase cycle
new moon -> waxing crescent -> first quarter -> waxing gibbous -> full moon -> waning gibbous -> last quarter -> waning crescent -> new moon
change in the moon's appearence from day to day
phases of the moon are caused by
the moon orbiting around Earth
T/F: the same side of the moon always faces Earth
New moon -> new moon is
NOT 1 revelution
1 orbit around Earth takes
27.3 days
New moon -> new moon takes
29.5 days
total shadow
partial shadow
T/F: Earth and the moon do not cast shadows ito space
lunar eclipse
occurs when the moon passes into Earth's umbra
a lunar eclips only occurs durring
the full moon phase
when the moons orbit is perfectly aligned with Earth's orbit
Solar eclipse
occurs when the moons shadow reaches Earth's surface
durring a solar eclipse, positions on Earth's surface inside the umbra have
total darkness
annular eclipse
when the moon is at apogee and he umbra fails to reach earth's surface
durring an annular eclipse the sun appears
as a bright ring around the moon
solar eclipses only occur durring the
new moon phase
individual locations experience a total solar eclipse about once every
300 years
rhythmic rise and fall of the water level at the coast and extremities every day
tides are caused by
the moons gravity as water flows over the tidal bulge, the level changes
cyclic tides change every
6 hours and 12.5 minutes
spring tides
higher than average high tides, lower than average low tides
spring tides occur
when the moon, earth, and the sun are aligned
reap tide
lower than average high tides, and higher than average low tides
reap tides occur
when the moon, earth and the sun are at a 90 degree angle
the sun composed
composed of hydrogen and helium
Galileo was the first to decribe the suns
solar telescopes
project a real image of the sun into a darkened room for observations
suns diameter
1 380 000 km
the suns diameter is
110 times greater than earths
the sun rotates every
25-27 days
how long for sunlight to travel from the sun to earth
8 minutes 20 seconds
light travels at a speed of
3.0 x 10⁵m/s
suns outer tempurature
5 500 C
suns interior tempurature
15 000 000 C
apparent bright, yellow surface of the sun
photosphere is
about 400 km thick
photosphere is made up of
individual cells
1 500 km across and have a bright center with dark edges
granules are the tops to columns of gas formed in the
faint red hue around the sun
chromosphere is caused by
the formation of helium in the star
seen as a faint halo around the sun durring solar eclipses
solar prominences
huge flame-like arches of plasma that occur in the corona
magnetic distortions in the photosphere
sunspots appear as
dark spots on the photosphere
sunspots occur in
sunspots have a
magnetic field (contains North and South poles)
sunspots create
cool spots on the photosphere
sunspots are darker due to
less solar activity
may be a difference of 1 500 C between sunspots and the
sunspots move
left to right across the suns surface
sunspots were first described by
solar wind
current of electrically charged particles emmited by the sun
solar wind average speed
400 km/s
coronal holes
large tears in the corona caused be strong "gusts" of solar wind
solar flares
outbursts of light that rise up out of sunspots
charged particles interacting with earth's magnetic field
solar wind can cause
solar storms
solar storms disrupt
satellite and ground based electrical transmissions
solar fusion
the suns energy source
the suns core is a
nuclear funace
the suns core is converting
lighter elements into heavier ones
the suns core releases
large amounts of energy
the sun is currently converting
hydrogen into helium
"missing" mass is converted into
Einstein's theory of general relativity
all planets orbit the sun in
elliptical orbits
oval shape
T/F: some planets orbits are more eccentric than others
2 pieces of info to calculate eccentricity of an ellipse
1. distance between 2 foci of the ellipse
2. length of the ellipses major axis(longest part of the ellipse)
the greater the eccentricity of the ellipse
the flatter the object
the lower the eccentricity of the ellipse
the more circular it is
eccentricity values range from
0.0 (circle) to 1.0 (straight line)
usually planets move
eastward across the night sky
planet in greek
at times, some planets appear to move
westward across the night sky
retrograde motions caused by
earth "catching up" and "passing" other planets in their orbital paths
when retrograde motion takes place
planets appear to move backwards across the night sky
retrograde motion is similar to
cars passing one another on the highway
geocentric model
model of the solar system with earth at the center and the planets and stars orbitiing it
geocentric model hypothesized by
less ertially "mini-orbits"
geocentric model show earth at
the center of the universe
geocentric model is made from
earthbound observations
heliocentric model
model of the solar system with the sun at the center with the planets and moons orbiting it
heliocentric model is the
current model
heliocentric model is made from
earthbound and spacebound observations
heliocentric model established by
Tycho Brahe
danish nobleman who made the 1st long-term observation of the night sky (about 20 years' worth)
Keplers 1 law of planetary motion
planets travel in elliptical orbits around the sun with the sun at 1 focus (a circle has 1 focus whereas an eclipse has 2 foci)
equal area law
each planet moves around the Sun in such a way that an imaginary line joining the planet to the sun will sweep over equal areas of space in equal areas of time
The speed at which a planet travels around the sun is not
planets travel rapidly when they are closer to the
law of harmonic motion
the amount of time it takes a planet to complete one orbit around the sun
the sequence of the period is equal to the distance between the
planet and the sun
period must be in
Earth years
astonomical units
distance between earth and sun
149.6 million km
the farther a planet is from the sun, the greater its
period of revolution
Dark line spectra can be used to
to show the composition of a stars or planets atmosphere
asd the center of the star gloes, light passes through
some light is obsorbed as it passes through the planets
when a stars bright line spectrum is shifted towards the red end of the spectrum
redshift is caused by
light being "stretched" as the distance between the source and the viewer on Earth is increasing
redshift shows that
the source and viewer are moving away from one another
when a stars bright line spectrum is shifted towards the blue end of the visible spectrum
blueshift is caused by
the compression of light waves as the source and the viewer on Earth are getting closer to one another
patterns of stars in the night sky
constellations are named after
animals, heroes, and symbols primarily from greek mythology
T/F: constellations never appear below the horizon in the northern hemisphere
constellations rotate around
some constellations are only visible durring certain
times of the year
visible constellations are dependent on
Earth in its orbit
astronomical unit (AU)
1 AU= the average distance between Earth and the Sun (149.6 Million km)
light year (LY)
distance light travels in 1 year
speed of light
300 000 km/s
1 LY =
9.5 trillion km
parallax second
parallax second
amount parallax shifts in 1 second of angular diameter
1 parsec =
3.258 LY
properties of star vary in
size, density, mass, and color
smallest stars
smaller than Earth (dwarf stars)
largest stars
supergiant stars 2 000 x larger than the Sun
most dense star
neutron stars (1 teaspoon of mass of neutron star = the mass of Earth)
least dense star
red supergiants
most stars are around the size of the
Sun (main sequence stars)
color of a star is determined by
its surface temp
hottest star color
coolest star color
most stars are primarily composed of
hydrogen and helium
apparent magnitude
how bright a star appears to an observer on earth
brightest star an scale
1st magnitude
faintest star on scale
6th magnitude
each magnitude differ by
2.5 x
stars brighter than 1st magnitude have a value
stars brighter than 0 have
negative values
brightest star
-1.46 (sirius A)
actual true brightness of a star
luminosity depends upon the
size and temp of a star
absolute magnitude
how bright a star would appear to be to an observer if all of the stars were 10 parsecs away from earth
absolute magnitude is used to
measure luminosity of stars
absolute magnitude gives an indication of
true brightness
giant stars color
can be red, yellow, white, or blue
as a stars size increases, so does its
super giant stars
largest of all stars
super giants are more luminous than
giant stars
shortest lived stars
supergiant stars
dwarf stars
smallest and least luminous of all stars
white dwarf
the reminant of a Sun-sized star after it ejects its outer layers by going nova
a white dwarf is
the very dense core of a pre-existing star
white dwarfs have high temp, but
low luminosity
brown dwarf
very small mass of steller matter that never got hot enough for nuclear fusion to start
variable stars
star that cyclically vary in brightness
pulsating stars
stars that vary in brightness as they expand and contract
cepheid variable
pulsating stars whose distance can be determined from its period of pulsations
eclipsing binars
2 stars of unequal brightness that revolve around and pass in front of each other at regular intervals
core of a neutrons star produced after a supernova
pulsars emmit bursts of
radio waves and light
stars formed by cluds of
dust or gas called nebulae
the initial size (mass) of the nebula determines wether the star will be a
dwarf, main sequence, massive, or supermassive star
as the gases in a nebula compress, they begin to
protostar is formed when
temp and pressure get to be high enough and fusion begins
diffuse nebula
made visible by the light of a bright nearby star passing through the nebula
dwarf stars formed
from the smallest and least massive nebulae
dwarf stars may also form at the end
of a stars lifecycle
massive and supermassive stars are a form of
extremely massive nebulae
massive and supermassive stars may be
10 to 16 x the Suns mass
massive and super massive star use of their fuel faster than
any other star
massive and supermassive stars have shorter lifespan than
main sequence stars
massive and supermassive stars tend to be
blue stars because the fusion is taking place so rapidly
at the end of a stars "life" all of its hydrogen fuel has been
used up
after a star has used up all its hydrogen it begins to fuse
helium into carbon
a star will fuse helium into carbon for
several billion years
burst of light as the star looses it outer layers
after a supernova, the remaining core can form a
white dwarf
a white dwarf has approximately the diameter of Earth, but has the mass of a
Sun-sized star
T/F: a pair of standar dice made of white dwarf material would weigh over 5 tons
if the star is a massive star, it starts to fuse carbon and oxygen into
heavier elements
after the star reached its "carbon-burning" stage
it cannot go any further
fusing the remaining iron in its core into heavier elements and scattering them across the universe as it looses its outer layer
a neutron star is formed by
the remaining ball of neutrons after a supernova
T/F: neutron stars are equal in mass to the massive star but are smaller than Earth
black holes are formed when
a supermassive star collapses from the force of gravity after it overcomes the resistance of the weight of the neutrons
quantum singularity
point of infinite density
quantum singularity is found where
the center of a black hole
T/F: black holes generate so little gravity that even light can escape
event horizon
the edges of a black hole that can distort time
supermassive black holes are thought to be essential to the formation of
spiral galaxies
black holes are detected by
bursts of x rays produced by their partner pulsar
galaxies contain
trillions of stars
our galaxy
milky way
galaxies are shaped like
closest neighboring galaxies
Andromeda and the Magellanic Clouds
spiral galaxy
central disc with 2 or more radiating spiral arms
elliptical galaxie
lense-shaped galaxy (has no nebulae)
irregular galaxy
has no shape
large stellar masses that produce bursts of radio signals.
quasars are thought to be
young galaxies developing
the big bang theory
states that the entire universe was once one gigantic ball of hydrogen
nebulae are formed by
hydrogen clumping together
universe is still
the shape of the universe