Transcript Astronomy Final Exam Review

Astronomy Final Exam
Review
The answers
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• Pseudoscience is a study that tries to
explain scientific phenomenon. It does not
follow the scientific method. An example
would be astrology.
• Astronomy is the study of objects in space;
astrology is the study of myths attached to
stars’ locations in relation to Earth, and
how this affects your personality.
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Kepler-3 laws of planetary motion
Copernicus-Heliocentric theory of the universe
Newton-3 laws of motion
Galileo- perfected the telescope
Brahe- greatest naked-eye astronomer of all
time
• Doppler-Doppler effect named for him; used
by Hubble to prove the expansion of the
universe
• Stonehenge-astronomic calendar in England
• Objective- main lens-forms a small image
• Eye piece- used to magnify image; make it
convenient
• Finder scope-larger field of view to find
object before magnifying it with the full
telescope
• Focus- brings the image into clear view
• The primary or main purpose of a
telescope is to enlarge objects that are far
away.
• The most powerful land telescopes are at
the tops of mountains in order to decrease
the effects of the atmosphere.
Reflecting telescope
• Radio telescopes pick up the invisible
portion of the spectrum, whereas optical
telescopes pick up the visible portion.
• In the future, telescopes will be multimirrored, and computer-aided.
• A prism is used to break white light into its
rainbow of colors. This is used to
determine the speed and distance of
galaxies.
• Spectroscopes are used to break white
light into colors, allowing astronomers to
determine what elements are in a star,
how far away objects are, and how fast
they are moving.
• Violet has the shortest wavelength, red
has the longest.
• Red shift- the object is moving away; blue
shift, the object is moving toward
• Altitude- height above the horizon
• Azimuth- degrees around the sphere,
away from north (0)
• Zenith-highest point; directly overhead
• Nadir- directly beneath you
• Horizon- where the sky appears to meet
the land
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A
B
C
D
E
F
75---170
45---90
20---345
5---270
45---250
20---45
• The big band theory states that the
universe began in an explosion of matter
and energy and has been expanding ever
since.
• Universe- 13 BY The sun- 4.6 BY
• The nebular theory states that the solar
system formed from a rotating cloud of gas
and dust, which condensed to form the
sun and all other solar system objects
Elliptical
Spiral
Barred Spiral
• Star- celestial object composed of gas, held
together by its own gravity, and supported by
nuclear fusion in its core
• Galaxy- very large collection of gas, dust, and
stars orbiting a common center of mass
• Nebula- star nursery
• Planetary nebula-remnants of a supernova
explosion
• Supernova- how massive and supermassive stars
begin the end of their lives (after red giant or
supergiant phase)
• Quasar- rare, starlike object that gives off radio
waves as material is sucked toward a black hole
• Light year- the distance light travels in a year
• AU-(astronomical unit)- 1AU= distance from Earth
to the sun
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Polaris- aka The North Star
Sirius- brightest
Alpha (Proxima) Centauri- closest
Betelgeuse- In Orion, largest
• A star’s color reveals its surface
temperature
• Stars are 75% Hydrogen and 25% Helium
• Apparent magnitude- brightness as seen
by human eyes on earth; Absolute
magnitude- intrinisic brightness; how bright
it would be at 10pc
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White dwarfs=A
Main sequence=D
Red giants= C
Supergiants=B
Sun will never be=B
Bluish main sequence= E
Red main sequence= F
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Mercury-no atmosphere
Venus-hottest, spins backward
Earth-only one with life
Mars-red; polar ice caps
Jupiter-largest; 63 moons
Saturn-brightest ring system
Uranus-Green; tilted 90 toward the sun
Neptune-blue; great dark spot
Pluto-no longer a planet
• We are able to see planets because they
are reflecting sunlight.
• As you increase the distance from the sun,
you increase the orbit time
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New moon-dawn-sunset-none
1st quarter-noon-midnight-half (right side)
Full moon-sunset-dawn-full
3rd quarter-midnight-noon-half (left side)
Earthshine
• Maria-lunar lowland filled by successive
flows of dark lava
• Highlands-mountains
• Craters-circular remnants of impact
• Copernicus and Tycho are the names of
craters (all craters are named after famous
scientists)
• Gravity on the moon is 1/6 that of Earth.
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1. core
2. radiative zone
3. convective zone
4. photosphere
5. chromosphere
6. corona
• Sunspots-magnetic storms on the sun’s
surface. They appear dark because they
are cooler than the surrounding surface.
• Sunspot cycle is an 11-year cycle of
sunspot activity that corresponds with an
increase in aurora activity.
• Lunar eclipse
red moon
S-E-M
1 hour
with every full moon, somewhere on Earth
Solar eclipse
moon blocking the sun
S-M-E
2-11 minutes (totality)
with every new moon (not total) somewhere
on Earth
• The orbits of the planets are ellipses with
the sun at one focus.
• No Need for Bode’s law
• Satellite-any object that orbits another
(manmade vs natural)
• Meteor-an object in space that gives off
light as it burns in Earth’s atmosphere
• Meteorite-the object strikes Earth’s surface
• Comets-objects beyond the orbit of Pluto;
give off a streak of dust and ice when they
get near the sun (tail)
• A meteor shower happens when Earth
passes through the path of a comet, and
the pieces of comet burn in Earth’s
atmosphere.
• Gravity is the attraction between two
objects that have mass.
• Inertia-an object in motion remains in
motion…
• Rotation-spin on an axis
• Revolution-orbit around another object
• Perihelion-closest to the sun in orbit
• Aphelion-farthest from the sun in orbit
• Asterism-a named group of stars not
identified as a constellation (ie. The Big
Dipper and Little Dipper)