Astronomy Test 2 Flashcards

Terms Definitions
Revolution
...
alt-azimuth mountings
...
8th planet
Neptune
Summer Solstice
June 20-22
Continuous Spectrum
Full Rainbow
zenith
the point directly overhead.
Why's Mars red?
iron minerals
stephen-boltzmann law
E=T to the fourth
continuous
(spectrum) heated solid --all colors
halley
discovered comets are cyclical phenomenon
Corona Borealis
constellation: the northern crown
Spiral Galaxy
Galaxy with spiraled arms.
Stellar Parallax
a measure of stellar distance
What color are the hottest stars?
Blue
Infared
700 - 105 nm (0.1 mm)
meridian
a half-circle extending from your horizon, altitude zero degrees, due south, through your zenith, to your horizon due north.
Stefan-Boltzman's Law
F is proportional to T4
quasars
starlike radio sourcewith an observed redshift that indicates an extremly large distance from earth. the brightness nucleus of a distant active galaxy
Spectrum
1. the intensity of electromagnetic radiation as a function of wavelength.
2. Waves sorted by wavelength
age of universe
14.7 billion years old
Neap Tides occur with _____ moons.
Quarter
Venus
*has thick atmosphere that reflects a lot of light, often the brightest "star" in the sky
*size & structure similar to Earth
*rotates slowly
*atmosphere has caused runaway greenhouse effect
star
a massive collection of gases, held together by its own gravity and emitting huge amounts of energy
horizon
The line that marks the apparent intersection of Earth and the sky
Scarp
(cliff), several hundred km long and up to 3 km high, thought to be formed as the planet cooled and shrank, cut across craters, so occurred after meteor bombardment
Johannes Kepler
correctly explained the sience behind ellipses in 1621
Fusion
the act of fusing (or melting) together
Apogee
Point when moon is farthest from Earth
nebula
What do scientists believe our solar system began as?
Instrument used to analyze light from stars
Spectrascope
zodiac
a band running around the celestial sphere in which planets move.
Retrograde Motion
Apparent westward drift of the planets
Radio Observations
specific molecules in giant molecular clouds
protogalactic cloud
A huge, collapsing cloud of intergalactic gas from which an individual galaxy formed.
Reflecting telescopes
Isaac Newton
Light bounces off mirror
Mirror can be very large
autumnal equinox
9/22, northern hemisphere fall, sun's declination is 0,
asteroids
-no planets in asteroid belt because of gravitational competition between sun and jupiter
-cratered
-can determine size, shape from observations of occultations of stars
hydrostatic pressure equilibrum
the balance of gravity pulling material towards the center of a star and pressure pushing it towards the surface.
Titan and Triton
two moons that have substantial atmospheres
opposition
the configuration of a planet when it is at an elongation of 180 degrees and thus appears opposite the sun in the sky
Reflection
What is it called when waves bounce off an object?
Giant
becomes red giant and then burns out and becomes dwarf
The path the sun makes through the stars is called the
Ecliptic
latitude
a measure of the distance from the equator, expressed in degress
Brown Dwarfs
Stellar models predict that stars less than 0.08Msun, do not get hot enough to ignite thermonuclear fusion.
counterclockwise
the Earth rotates ___ (that's why the Sun appears to rise in the east and set in the west)
moon
any natural satellite of a planet (an object that orbits or revolves around a planet)
Planetesimal
a small body from which a planet originated in the solar system's early development.
Seeing
Blurring of an image by the Earth's atmosphere
What type of star is the sun
Minor variable.
Circumpolar
part of sky that never sets, depends on latitude
Tides
the regular rise and fall of the ocean's surface influenced by the moon's gravity pulling on earth. Occurs evrey 12.5 hours or so
Nuclear Fusion
atoms are being forced together to fuse, creates lots of energy.
Optical telescope types
Refracting: focuses light w/ lenses. Expensive & suffer from chromatic aberration.

Reflecting: focus light w/ mirrors. vary in cost aberrations determined by the design.

Some use both, usually expensive.
eclipse
the obscuration of the light of the moon by the intervention of the earth between it and the sun
exponent
the power of 10 of the number in scientific notation
during the full moon phase.
A total lunar eclipse occurs
Craters
a large round pit caused by the impact of a meteoroid
What does temperature measure?
The average kinetic energy of particles in a substance
White Dwarfs are about the size of the earth
True
constellation
one of the 88 regions which the sky has been divided in order to describe the locations of celestial objects
giant star
A very large star, much larger than the sun. Our sun will become one of these one day far in the future. This is the coolest type of star.
Winter Solstice
December 21st - winter solstice in the Northern Hemisphere, summer solstice in the Winter Hemisphere. (When the Sun is lowest in the sky.)
refracting telescope
a telescope that uses convex lenses to gather and focus light
great red spot
huge hurricane storm on jupiter, twice size of earth
epicycle
the circular orbit of a planet in the Ptolemaic model, the center of which revolves around the Earth in another circle
Constellations (T.K)
an imaginary pattern of stars in the sky that form pictures of animals or people
Solar Eclipse
the blovking of sunlight to earth that occurs when the moon is directly between the sun and earth
Full Moon Phase
7-8 days after first quarterwe see 100% of the moon's day sideOnly phase where the sun and moon are opposite in the sky
t or f: the celestial north pole lies directly above the earth's north pole
t
what marks the beginning of spring?
vernal equinox on March 21.
Right Ascension and Declination
Which coordinate of a strremains the same throughout the night?
Solar wind
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun.
Minute of arc
An angular measure. 1/60th of a degree of arc. (129,600 seconds 21,600 minutes 360 degrees of the celestial sphere)
Newton's Discovery About Light
When shining white light through a prism, he found that it's comprised of all the colors of visible light spectrum
FUEL for reaction within main sequence stars
Helium and Gamma Rays
Meteor
Travel at speeds of 35 to 95 km per second and burn up in the earth'stmosphere
Bok globule
Small, dark cloud only about 1 ly in diameter that contains 10 to 1000 solar masses of gas and dust. Believed to be related to star formation. (p. 166)
What is an emmision spectrum?
Wavelengths of light emmited by a particular substance.
how long does it take for light from the sun to reach earth
about 8 min
Why is a nova so bright?
Because the process blows the remaining gases off the white dwarfs surface and produces the bright light.
when we see a dust cloud on one side of a star , the cloud appears to be ______ the star
bluer than
Top to bottom of stars HR diagram
Super giants, giants, main sequence, white dwarfs
Kepler's first Law: Planetary orbits are...
ellipses, with the sun at one focus.
We observe that the velocities of galaxies, relative to us, are proportional to the distances of the galaxies from us. This particular observation tells us that the observable universe: (a) is centered on us. (b) is undergoing a uniform expansion. (c) has
(b) is undergoing a uniform expansion.
Population II stars have orbits that _____ Population I stars
are heavily inclined to the galactic plane (disk), unlike
The First Law of Planetary Motion
The orbit of each planet around the sun is an ellipse with the sun located at one focus
Why don't all supernova remnants contain pulsars?
The pulsar may be tipped so that the beams do not sweep past Earth.
What are the stats of the Seyfert Galaxies? 4
1. Most radiation comes form the galactic nucleus.
2. Brightest are 10,000 time brighter than the Milky Way.
3. Most energy at radio and infrared wavelengths--non stellar.
4. Spectra show emission lines of highly ionized (missing many electrons) heavy elements (like iron) --not typical stellar absorption spectrum.
in order to get the best resolution, where in the solar system should a radio telescope be put
jupitor, moon, as far out as you can
What is the criteria for a planet?
1) Must have enough gravity to form a sphere
2) Must orbit the Sun (or star)
3) Must be dominant object in part of solar system. If smaller objects, must be satellites. Able to clear out with its gravity.

Believed to be designed to exclude Pluto.
it must move at the same speed but in the opposite direction of the earth
In order to study the stars, what must your telescope do?
reconnections
...
convective zone
...
Universe=all space+time
Galaxy=collection of celestial bodies
Universe/Galaxy
Newton
laws of motion
Longer wavelength
Low energy
moon's surface
crates, maria, highlands
Penumbra
partial shadow or eclipse
______ wavelengths have higher energies
shorter
Hydrostatic Equil.
force are in balance
Dwarfs
Smallest stars in the universe
Heliocentric Theory
A sun-centered solar system
extremophiles
organims live in very harsh environments
configuration
a particular geometric arrangement of the earth, a planet, and the sun
emission
a light bulb emits visible light
Quarter
1/2 the moon's face is lit
light was made of waves?
Christianus Huyghens
Deposition
Final stage of the erosional process
electromagnetic radiation
radiation consisting of oscillating electric and magnetic fields, namely gamma rays, X rays, visible light, ultraviolet and infrared radiation, and radio waves.
Kepler's 3rd law of planetary motion
p^2=a^3
Asteroid
often refered to as minor planets
Ceres is the largest
Blackbody Spectrum
• The underlying continuous spectrum of most objects is well approximated by the Planck curve. .
o A perfect absorber and emitter of radiation.
o We must distinguish between the light emitted by an object and the light reflected by that object.
axis
an imaginary line that passes through Earth's center and its North and South Poles, about which Earth rotates
What are the brightest stars called?
blue giants
Io is the most volcanically active place in the Solar System. T or F
True
weight
the force of gravity on an object
equatorial jet
the high-speed, eastward, zonal wind in the equatorial region of Jupiter's atmosphere
3 'floating' things in space?
asteroids, meteors, comets
Temperature of the Sun's core
16 million K
stony meteorite
(chondrites) a meteorite composed of rock with very little iron; also called a stone.
Types of Lunar Eclipes: (3)
total, partial, penumbral
vernal equinox
equal days and equal nights, spring
Ionize
The process by which electrons are stripped free from an atom or molecule, resulting in free electrons and a positively charged atom or molecule
Strong Nuclear Force
Overcomes electromagnetic force inside an atomic nucleus. Short range
Northern Hemisphere
The northern part of the earth.
Where are 21-cm radio lines observed?
Interstellar space
dark matter
Nonluminous matter that is detected only by its gravitational influence. (p. 263)
The HR Diagram shows the relationship of a stars surface temperature and what else?
absolute magnitude
vibrating electric charges
source of all electromagnetic waves (path is straight as it travels through space)
angular resolution
the angular size of the smallest detail of an astronomical object that can be distinguished with a telescope
Waxing Phase
More of Moon's illuminated surface can be seen each night; moon's illuminated surface is growing.
Mantle
Middle layer of the moon, makes up moon's volume, made of dense rock.
free fall
falling without any resistance to slow you down, floor drops at same rate you fall (float)
Year
The time required for the Earth to orbit once around the sun
quasar
distant stars that show a very high red shift and are thought to be young versions of active galaxies
Doppler effect
phenomenon that causes shifts in the wavelengths of light
Umbra
the very darkest part of the moon's shadow
In our solar system, which of the following planets is a member of the terrestrial group?
Mars
Uranus
7th planet, tipped on its side, faint rings
How is resolution determined?
wavelength / diameter of telescope
fainter/ brighter
The "Sun in Time" project shows that when our sun first formed it was _________ in visible light and _________ in high energy (UV and X-ray) light, when compared to its present day values.
Eclipsing Binary
a star system in which one star periodically blocks the light from another
apparent magnitude
the brightness of a star when viewed from Earth
cometary dust tail
after leaving the nucleus, dust is pushed away by radiation pressure from sunlight; it is seen because the dust grains scatter sunlight
moon phase
change in appearance of the Moon as viewed from the Earth, due to the relative positions of the Moon, Earth, and Sun
Refraction
the bending of a wave caused by a change in its speed as it moves from one medium to another.
Kepler's 1st Law
Law that states: Planetary orbits are ellipses with the Sun at one focus
This is created when a white dwar star steals hydrogen from its companion star and once again ignites
Nova
True or False
Mercury is the hottest planet because it is nearest the sun
orbit
the path of an object as it revolves around another object in space
Meteoroid
Tiny particles the size of a grain of sand that elliptically orbit the Sun
What is "seeing"?
The fact that the earth's atmosphere has a lot of turbulence and when light passes through it it gets distorted, so no matter how good your telescope's resolving power is, it probably wont resolve better than about 1 arc second.
Who is considered to be the first LDS astronomer
Orson Pratt
Main-sequence Turnoff
the location on the H-R diagram of a single-aged stellar population (such as a star cluster) where stars have just evolved off the main sequence; the position is determined by the age of the stellar population
wave particle duality
electrons and light can behave as both a wave and a particle
Summer Solstice -
June 22- Northerly most point on the ecliptic
Majior surface features of the Moon: (6)
mare/maria, highlands, craters, rilles, mountians, and domes
Penumbral Lunar Eclipse
a lunar eclipse in which the moon passes through the penumbra of Earth's shadow
the approximate diameter of a red giant star
ten to the fourth
Phases of the moon
apparent changes in shape of the moon caused by different views of light and shadow
Mirrors are less expensive to fabricate then lenses, weigh less, have larger magnification
Large reflector telescopes have the following significant advantages over large refractors:
red giant branch
a region on the H-R diagram defined by low-mass stars evolving from the main sequence toward the horizontal branch
North and South Celestial Poles
points in the sky directly above earth's north and south poles
the inner and outer moons of jupiter differ how?
inner moons have less ice
Telescope a "time machine"?
Yes a telescope is a time machine, the light we observe from distant parts of the universe takes a long time to reach us.
How does temperature affect the rate of hydrogen fusion?
If temperature is slightly decreased, the fusion rate would lower. If temperature is slightly increased, the fusion rate would get higher.
Explain how the Earth's magnetic field interacts with the solar wind to both protect life on Earth and create the aurorae visible in the atmosphere in the North and South Polar Regions.
The magnetic field shields the Earth from solar wind, because high-energy particles, plasma, do not easily cross magnetic fields. For the most part solar winds go around the planet, but some charges circle and spiral into the Earth's atmosphere. The solar wind spirals to Earth and becomes harmless, eventually landing at the North and South Polar Regions and reacting with the gases there. This creates beautiful and harmless auroae.
Each choice below describes how a few astronomical phenomena are related to time periods. Which list is entirely correct?
Earth's rotation defines a day.
The cycle of the Moon's phases takes about a month.
Earth's orbit defines a year.
Earth's cycle of axis precession takes 26,000 years.
What is the definition of circumpolar stars?
Stars that appears never to rise or set.
*There you are closer to celestial objects
*You are above most of the carbon dioxide and water vapor in the atmosphere
*The cold weather helps the sensitivity of infrared detectors
*Less air above means beter seeing in many cases
A mountain top is an especially good site for infrared telescopes since:
What is the angular resolution of the human eye?
about 1 arcminute, or 1/60 of a degree.
A light year is shorter than: (a) a year. (b) the distance to the sun. (c) the distance to the nearest star (other than the sun) (d) a century
(c) the distance to the nearest star
distance in...
centimeters
neap tides
20% lower
radioactive dating
radiometric dating.
Cluster
a group of galaxies
Inner planets
Mercury, Venus, Earth, Mars
"braking radiation" process that occurs when electrons encounter protons and emit solar flare x-rays
bremsstrahlung
physical distance between two crests
Wavelength
solar flare
hot spot on photoshere
Photodisintegration
process occurring at high temperatures, in which individual photons have enough energy to split a heavy nucleus
Saturn
has rings made mostly outof ice
jovian planet
the jupiter-like planets: Jupiter, Saturn, Uranus, and Neptune; these planets have relatively low densities and are huge gas giants.
Period-Luminosity Relation
Determines luminosity by measuring time-period over which brightness varies
thermal pressure
balance gravitational forces in main-sequence stars
Belt
dark, reddish, low-pressure bands in Jupiter's atmosphere
What compound detected in surface rocks by the Mars Odyssey orbiter and explored by the Opportunity rover suggests evidence for past water on Mars?
hematite
Newton:
GRAVITY keeps planets/moon in orbit [ex. New(graviTy)on]
equinox
when earth's rotation is perpendicular to line joining earth and sun = sun resides at midpoint in sky = 12 hours day and night.
the magnitude system
-Brightest stars (roughly)--1st magnitude
-Faintest naked eye stars (roughly)-- 6th magnitude
-difference in 5 magnitudes corresponds to a factor of 100 in intensity, so each magnitude corresponds to a factor of about 2.5.
Hydrostatic Equilibrium
When collapse of gravity equals pressure from interior; defines the size / how big the sun is (gravitational pull of earth not strong enough to compress composition of rocks)
Theory
"System of rules and principles that can be applied in a variety of circumstances, hypotheses that have been tested, expanded and generalized"
Red-shift
a decrease in light frequency and increase in wavelength due to movement away
Radio Galaxies
AGN at center
-having very strong emissions in the radio part of the electromagnetic spectrum
Neptune
usually the eighth planet from the Sun; is large and gaseous, has rings that vary in thickness, and is bluish-green in color
solstice
twice-yearly point at which the Sun reaches its greatest distance north or south of the equator
Outer Planets
large and composed mostly of gases.
blueshift
a shift of all spectral features toward shorter wavelengths; the Doppler shift of light from an approaching source.
astronomy
is the science that studies the composition, position, and movements of all objects in space.
spicules
filaments of cooler gas from the photosphere rising up into the chromosphere through supergranules
Protoplanet
a larger body formed when plantesimals joined together.
Occam's razor
The principle that the simplest hypothesis is the most likely; named after William of Occam (circa 1285-1349),
Waxing
describes phases following a new moon, as more of the Moon's lighted side becomes visible
number of galaxies in the universe
100 billion
electromagnetic spectrum
the entire frequency range of electromagnetic waves
Ptolemy
(85-165 A.D.) Made a model that explained for the motion of the planets. Thought that Mars moved backwards. Added epicycles to his model.
proton-proton chain
a series of three nuclear reactions that builds a helium atom by adding together protons. main energy source in the sun
Comet
A small space object consisting of ice and other compounds.
what planet was named after the roman god of the sea?
neptune
standard candles
Objects where we can estimate the luminosity in this way and use their apparent brightnesses to determine distances are called
crater
the depression at the summit of a volcano or that which is produced by meteorite impact
degree
A unit of angular measure or a temperature measure.
baseline
a dish whose diameter was the distance between the two radio telescopes
longer
The length of the Eclipse season is ___ than the synodic month.
lunar eclipse
when earth's shadow falls on the moon
precession
is the slight movement, over a period of 26,000 years of Earth's axis
Synodic Period
an object orbital or rotational period measured with respect to the sun
Horizontal Branch
Core nuclear fusion: converting He to C. Leaves the horizontal branch when the core runs out of He.
mercury, venus, earth, mars, jupiter, uranus saturn, neptune, pluto
order of planets
same
stars in a constellation are in the _____ part of the sky
same
different
Increasing LUminosity
white dwarf (small bright dead cores of stars like our sun) Sun Red Giant
Tail
gas and dust that streams out of a comet as it approaches the sun and heats up
William Herschel
attempted to gauge the true shape of the Milky Way star system by counting stars in 683 different directions in the sky.
radio galaxy
A galaxy that gives off large amounts of energy in the form of radio waves.
full moon
phase that occurs when all of the Moon's surface facing Earth reflects light
_________ observed in various regions of interstellar space.
21 cm radio lines
Jupiters core composition
made of rock, metals and H compounds
Cepheid Variable Stars
These special stars vary in brightness are are used for measuring distances to galaxies.
radio telescope
a device used to detect radio waves from objects in space
planet
A large body that orbits a star and reflects its light.
Spring and fall equinox
March 21st when the Northern Hemisphere tips slightly towards the sun and September 22 when the Northern Hemisphere starts to tip away from the sun
seasons
the ones on Earth are caused by the tilt of the Earth's axis and its revolution around the sun
Moving electric charges create __________
Magnetic fieldsMany planets have them.Need molten material inside the planet.
bok globule
a dense spherical cloud of gas and dust in interstellar space that absorbs light from stars.
spectral lines
atoms give off or take up radiation at certain colors, such as hydrogen
white dwarf
the small dim white hot core of a former Red Giant. very dense
The big bang theory
the theory that explains the formation of the universe
explain the magnitude scale
integers from the negatives to the positives, the lower the number the brighter an object is. between each object is a 2.51 difference, so between 2 numbers there is a 6.25 difference.
what is the ratio of light gathering power of a 10m telescope to a 1 m telescope?
100 to 1
What is the speed of light in free space (that is a vacuum)?
186,000 mi/sec
In science, a broad idea that has been repeatedly verified so as to give scientists great confidence that it represents reality is called _________.
a theory
T Tauri wind
"after the sun lit up a strong "wind" of particles swept light elements out of the inner solar system, leaving small planets composed of relatively heavy elements."
double planet system
the moon is so large relative to Earth that it is known as a
conservation of angular momentum
as long as there is no external torque, the total angular momentum of a set of interacting objects cannot change
How does impact cratering occur?
production of crater by an impacting object.
Spring Tide
When the Earth, sun and moon are in a straight line, the combined gravitational force produces a spring tide. This produces a tide with the greatest difference between low and high tide.
what keeps saturn emitting so much energy
differentiation (rain drops sinking to inside of planet)
characteristics of rich clusters of galaxies
1,000 or more galaxies, diameter of about 3 Mpc condensed around a large central galaxy
Energy is emitted or absorbed in the form of photon when
An electron changes it's orbit
Though Titan is small, it is able to retain an atmosphere because
It is very cold.
2nd Law of Planetary Motion
A line joining a planet and the Sun sweeps out equal areas during equal intervals of time
(Planets move faster the closer they are to the sun)
Moon and sun are at right angles with respect to the earth
Neap tides occur when the______
Tell how gravity works or what it is
the force or attraction between two objects, the more massive and object is, the stronger the force
What is the central idea of universal expansion?
Looking deep into space means looking far back in time, placing a limit on the portion of the universe that we can see. Galaxies move randomly within the local group.
Venus is always referred to as the "morning star" or "evening star" because it is always seen in the sky close to sunrise or sunset. Why can't you see Venus in the sky at midnight? Again, a diagram may help.
- You cannot see Venus at midnight because its orbit is interior to Earth's orbit. Meaning it is always going to be closer to the sun, and at midnight the sun is not visible.
Why are Moon rocks so much older then Earth rocks, even though both worlds formed at nearly the same time?
There is very little erosion on the Moon.
comparison spectrum
...
hertz
discovered radio
blue
hottest star color
Gibbous
Half lit moon
mars.
tilt similar to earth
Halo
Contains globular clusters, is spherical in shape, contains pop II stars and very little interstellar gas and dust
fourth stage of stars
red giant
craters on moon created by...
impact
What is uranus made of?
gas.
Mars
Has 1/150 of Earth's pressure
Satellite
man-made equipment that orbits around the earth or the moon
Neutron stars are approximately the size of the Earth
False
Eudoxus
proposed all heavenly bodies are embedded in giant, transparent sphere that revolved around the earth. needed a complete set of 27 interlocking spheres to explain observed celestial motions
Elliptical
Which types of galaxies are bigger?
wave speed
___ = (wavelength) x (frequency)
Planck Era
Before 10^-43
-Can't measure energy and time at the same time
Ecliptic
the great circle representing the apparent annual path of the sun
type II comet tail
See dust tail.
Corona
the outermost region of the sun's atmosphere
On what date does winter begin?
December 21st
Keck telescope
largest collecting aperture of any telescope
Luminosity
1 Watt = 1 Joule/second: independant of time
planck curve
relationship between energy of a photon and its wavelength E=hc/wavelength
Ice Giants
water, ammonia, methane ice, Uranus, Neptune
Flux
measure of light energy related to intensity
equator
an imaginary line that circles Earth midway between the North and South poles
temperature
speed at which an object's constituent particles move
jovian
of or pertaining to or characteristic of or resembling the planet Jupiter
Dione:
bright leading side and dark trailing side. many craters
Which planet has the largest satellite in the Solar System?
Jupiter
thermal equilibrium
the relationship between two isolated systems the states of which are such that no net transfer of energy would occur between them if they were connected by a diathermic wall.
optical telescopes
telescopes that collect light, may use lenses or mirrors
coude focus
a reflecting telescope in which a series of mirrors direct light to a remote focus away from the moving parts of the telescope
Heliocentric
In _____ models, the Sun assumedas the center of solar system.
The composition of a planet can be
determined by ...
Spectroscopic measurements
binary stars
two stars revolving around a common center of mass under their mutual gravitational attraction
how bright an object appears from earth
apparent magnitude
speed of light
what "c" stands for in E=mc^2
Rotation
the spinning of an object around its axis
nebular hypothesis
sun and planets were formed together out of one huge cloud of gas, mostly hydrogen
Terrestrial
of or relating to or characteristic of the planet Earth or its inhabitants
true
TF Hubble's law implies that, at some time in the past, all the galaxies were at one place
ex:m81
in ursa major. it is a perfect spiral
most to least mass
jupiter, earth, neptune, titan, halley's comet, an average meteroid
Right Ascension
- angle measured from the vernal equinox/celestial equator
- measured in hours
- 1 hour = 15 degrees
Sidereal period...
the orbital period of one object about another measured with respect to the stars
Galileo was able to measure the heights of lunar by using what?
the mountains shadows
who was the first American in space?
Alan B. Shepard
each chemical element
produces its own unique set of spectral lines when it burns
galaxy
a great island of stars in space, all held together by gravity and orbiting a common center
parallel lines that go east to west on the globe
latitude
roche limit
area around a planet that will break up a moon
annular eclipse
moon sometimes to far (at apogee) to completely cover sun
Light Year
The distance light travels in a year - 300,000km per sec or 9,450,000,000000 per year
plasma
a state of matter that starts as a gas and then becomes ionized
Electromagnetic Waves
They vary in length but they are all the same in speed, are capable of going as fast as speed of light- just different wavelengths
black holes
is a region of space in which the gravitational field is so powerful that nothing, not even light, can escape its pull after having fallen past its event horizon.
300 billion
how many stars do we now estimate are in the milky way?
Know what white dwarfs are
The remains of medium mass stars.
HR diagrams plot stars as a function of their
Luminosity and temperature
Kepler's second law
as a planet moves around its orbit, it sweeps out equal areas in equal time intervals
What is Roche Limit?
the closest a satellite can approach a planet without being broken apart by tidal forces,about 2.4 times the radius.
Quail Egg: People involved
1. Russian space station Mir 2. Five member crew included an astronaut from the Canadian Space Agency
chemical evolution has taken place elsewhere in the universe
large molecules found in meteorites and interstellar clouds is evidence that ____ ______ ___ ____ ____ ____ __ ____ ______
Quintessence is the name of the
Hypothetical form of dark energy; postulated to explain the accelerating universe
Observable stars and star groupings in other galaxies are
massive main sequence stars and supergiants
One way to experience weightlessness is:
falling freely from an airplane or amusement park ride.
A spiral galaxy with a flat, rectangular central mass is a ______ spiral galaxy.
Barred. Named after the central regions' characteristic bar shape, these appear to be far more common than "regular" spiral galaxies.
when directed toward the Earth, the CMEs distort the earth's magnetic field, feeding low energy charged particles into the outer Van Allen belt
How do coronal mass ejections affect the outer Van Allen belt?
The hurricane on Jupiter is called what?
The Great Red Spot
-stable & always present
What is the evidence that water once flowed on Mars?
dry river beads, islands shaped from erision , flood channels, ejecta blankets impresion of liquid spashed or flowed
Some of the jovian moons have volcanism,
much as some of the terrestrial planets do.
This can happen even for moons where tidal
heating is not strong enough to melt rock
because
ice geology can operate at the much
lower temperatures of those moons
True or False: Mercury is brighter than Venus.
False. Venus can be seen from Earth as well as the Sun.
At what phase would you expect to find the most intense tides?
D. both new and full Moons
At what phase would you expect to find the most intense tides?
A. new Moon
B. first and third quarter
C. full Moon
D. both new and full Moons
E. Moon phases are not affecting the tides
If you know the value of the Hubble constant you can: (a) win a Nobel Prize. (b) predict the fate of the cosmic expansion. (c) make a rough estimate of how long the universe has been expanding. (d) solve the flatness problem.
(c) make a rough estimate of how long the universe has been expanding.
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