MidTerm Flashcards
There are ___ minutes in a degree
60
There are ___ seconds in a minute
60
Imaginary structure surrounding earth, to which the stars are affixed
Celestial Sphere
This point on the celestial sphere is directly above the Earths north pole
Celestial North Pole (CNP)
This point on the celestial sphere is directly above the Earths south pole
Celestial South Pole (CNP)
This great circle on the celestial sphere is directly above Earth’s equator
Celestial Equator (CE)
Instead of latitude, celestial equatorial system coordinates use lines of
declination
Instead of longitude, celestial equatorial system coordinates use lines of
Hours of Right Ascension
This great circle is the boundary between the earth and sky
Horizon
This point is at the top of your sky
Zenith
This line stretches from North through the Zenith, to South___
Meridian
In the horizon system, an angular measurement of height is called
Altitude
In the horizon system, an angular measurement of compass direction is ___
Azimuth
The sun, moon, stars and planets rise in the ___ and set in the ___; this is due to the earths ___
east, west, rotation
There are ___ hours in one solar day
24
The sun is highest in the sky at ___
Culmination
Earth’s orbital path around sun, or sun’s yearly path in our sky
Revolution
Due to earth’s revolution, the sun seems to move ___ against the starry background.
1 degree
The sun, moon and planets are all found on or near this line:____
ecliptic
The ecliptic is also the center line of the ___
Zodiac
During what season do these constellations appear in the mid-evening sky? Orion, Scorpius, Leo, Pegasus
Winter, Summer, Spring, Fall/Autumn
The beginnings of summer and winter are called
solstices
The beginnings of spring and fall are called
equinox
The point in a planet’s orbit when its nearest the sun
perihelion
The point in a planets orbit when its farthest from the sun
aphelion
Month when earth is at perihelion; at aphelion
January / July
When earths northern hemisphere has summer, the southern hemisphere has
winter
The reason why we have seasons on earth:
23.5 degrees of tilt
Roman / Norse god: Sunday
Sol
Roman / Norse god: Monday
Luna
Roman / Norse god: Tuesday
Tiw
Roman / Norse god: Wednesday
Woden
Roman / Norse god: Thursday
Thor
Roman / Norse god: Friday
Freya
Roman / Norse god: Saturday
Saturn
Official, generally mythological grouping of stars
constellations
Number of officially recognized constellations
88
Because the stars are very far away from us, their angular velocities are great; so today’s constellation patterns are very different from those of thousands of years ago - T/F?
False
Unofficial, easier to see star grouping
Asterism
Example of an asterism
Ursa Major = Plough (England) or Chariot (Rome)
Our current North Star, this star lies very near the north celestial pole
Polaris
Constellations typically have ___ names
Greek
Stars typically have ___ names
Arabic
“Betelgeuse” means this:
the armpit of the giant
Why do you think Aldebaran is called “the follower”?
Follows the Hyades Cluster (Head of the Bull)
The Greek alphabet is used for this stellar purpose
measuring brightness
The “name” of Alpha Canis Majoris
Sirius
This stars altitude equals your latitude in earths northern hemisphere
Polaris
Where on earth would you be if you never could see Polaris
southern Hemisphere
Constellation that never sets below the horizon
Circumpolar
Are any constellations circumpolar at the north pole
All
Are any constellations circumpolar at the equator
None
The only circumpolar constellation for our latitude
Ursa Minor
What is our latitude in this part of Florida?
27.5
The carious appearances of the moon, its various apparent shapes, are called
Phases
Due to its revolution of earth, the moon moves ___ against the stars during the month.
13 degrees
Like the planets, the moon shines not by its own light, but by reflected
light
The dark regions on the moon are called
Maria (plural) or Mare (individual)
27.3 day orbit of the moon about the Earth
Sidereal month
29.5 day cycle of moon phases
Synodic month
This line separates night from day on any moon or planet
Terminator
Term to describe sun, earth and moon in a rough aligment
Syzygy
Can you see the new moon?
No
Term to describe when the sun and moon are together in the sky
Conjunction
Term to describe when moon is on the opposite side of sky from sun
Opposition
When the moon appears to grow fuller night after night
Waxing
When the moon appears to diminish night after night
Waning
Phase of moon after new moon
Waning Crescent
Phase of moon one week past new
Quarter
Phase of moon when it appears egg-shaped
Gibbous
Phase of moon when its fully lit
Full
What does a quarter moon look like in the sky?
Half Lit
Because earth revolves about the sun, moonrise is delayed about ___ minutes earch day
50
Rise time for New Moon ___; 1st Quarter ___; Full___; 3rd Quarter
With the sun; Noon (sets at midnight); Sunset (set sunrise); Midnight (set noon)
Why is the synodic month longer than the sidereal month?
Based on position in sky
For every one revolution of the moon about the earth, the moon makes on full rotation on its axis - T/F?
True
This ancient structure in England may have been used to predict the change of seasons and eclipse of the sun and moon
Stonehenge
We don’t know much about ancient megalith builders because they left few ___ records
written
In Mesopotamia, eclipses, comets and the planet appearances were recorded on ___
clay and stone tablets
___ were used by native Americans to record the position of the sun through the year
Medicine Wheels
These Meso-American people made careful observations of the sky and great calendars:
Aztec, Maya, Inca, Toltec, Olmec
An ancient model suggested Earth was on the backs of 4 ___ that stood on a great ___
elephants, turtle
Egyptian sky goddess, often depicted on tomb and sarcophagus paintings:
Nut
Ancient Egyptians measured the length of the ___ and knew it was about ___ days long
year, 365.25
To ancient Egyptians, the most important star was ___ known to them as Isis or Sothis
Sirius
When a star rises just before the sun comes up, its known as a ___ rising.
heliacal
___ stars were bright stars, spread out about every 10 degrees across the sky
Decanal
The rising of decanal stars through the summer night established our time period of the ___.
hours
The sun’s eastward movement through the background of stars is about ___ degree a day.
1
Egyptian ___ included hippopotamuses, alligators, jackals, and heroes.
constellations
Of the Seven Wonders of the World, only this one remains standing
The Great Pyramid (of Khufu)
The Great Pyramid is oriented toward the four main or ___ directions.
cardinal
To ancient Egyptians, Orion represented the god of the afterlife
Osiris
Stars and constellations in the northern sky which never set below the horizon
circumpolar
A very slow 26,000 year wobble in earths rotational axis
precession
Due to precession, our North Star has not always been ___ to the Pharaohs, it was ___
Polaris, Thuban
Although people long ago carefully observed the sky, they had no real ___ of what was going on.
understanding
“The father of astronomy”, he predicted eclipses and thought the world a flat disc:
Thales of Miletus
He argued that the cylindrical earth was at the center of a boundless universe
Anaximander
He thought the circle & the sphere to be perfect, that the universe consisted of trans-parent spheres that carried everything about a round earth, and the “Music of the Spheres”
Pythagoras
He thought the heavens perfect & unchanging, the earth imperfect, round but stationary
Plato
Plato thought the planets orbited earth in perfect circles at unchanging speeds:
uniform circular motion
By “saving the phenomenon” or “saving appearances” Plato meant that if the facts didn’t fit his theory, then you discarded the ___
facts
The Greek word “planetes,” our modern day “planet” means ___
wanderer
When a celestial object reaches its highest altitude in the sky & is on the meridian:
culmination
West to east motion of the planets against the background of stars over time:
prograde
Seeming backwards motion (east to west) of the planets over time
retrograde
He advanced the stationary earth and the geocentric model, citing the lack of this:
parallax (Aristotle)
The reason why Aristotle could not detect stellar parallax:
distance of stars
Aristotle cited this as strong evidence for a round earth:
lunar shadow (round)
Aristotle said earth was larger than the moon because
Earths shadow was larger
He taught that earth was a planet that rotated on its axis and revolved about the sun:
Aristarchus of Samos
He died in exile from Athens because he said the sun was not a god, but a flaming ball:
Anaxagorus
This Alexandrian librarian measured the circumference of the earth
Eratosthenes
Equation for finding circumference?
(360 / angle of planet) * mileage between two cities
He catalogued constellations and stars, and assigned the stars magnitudes:
Hipparchus
The brightest stars are ___ magnitude; stars that are 2.5 times dimmer are ___ magnitude; the faintest stars are ___ magnitude and are ___ times dimmer than 1st
1st, 2nd, 6th, 100
With modern telescopes, we can see things as faint as ___ magnitude
30th
Bright objects, like Venus, have ___ magnitude which is
negative, -4.4
Full moons magnitude
-12.6
Suns magnitude
-26.73
Decimal values are used to replace ___ numbers when it comes to magnitude
whole
The Green alphabet is used to provide ___
designations
The brightest star of a constellations is designated as ___; second brightest is ___
alpha, beta
Alpha Canis Majoris magnitude
1st; a
Beta Orion magnitude
2nd; b
Eta Ursa Majoris magnitude
7th; n
He wrote a compendium of Green knowledge of natural history, including astronomy
Claudio Ptolemy
Smaller planetary circle attached to Ptolemy’s deferent (the big circle)
epicycle
This book was the sum of Greek mathematical, geographic and astronomical knowledge
Syntaxis (Algamast)
Another name for the geocentric model:
Ptolemaic
Two celestial objects that share the same coordinate positions in the sky:
conjunction
When the ___ & the moon or a planet are in the same part of the sky, that’s a conjunction
sun
These are inferior planets: ___ and ___
Venus, Mercury
These are superior planets:
Mars, Jupiter, Saturn, Uranus, Neptune, Pluto
When an inferior planet is between earth and the sun
Inferior Conjunction
When the sun is between earth and an inferior planet
Superior Conjunction
When the moon or a planet is 90 degrees from the suns position
quadrature
When the earth is between the sun and a celestial object (180 degrees from the sun)
opposition
Can you see Venus or Mercury at midnight?
No
Traditional name for a planet seen in evening; in the predawn morning?
Evening Star, Morning Star
In the 16th century, he proposed the Earth orbited the sun with other planets
Copernicus
Copernicus’ model where sun is at the center of it all
Heliocentric
In the heliocentric model, the rising and setting of the sun, moon and stars is due to
Earths rotation
In the heliocentric model, the eastward motion of the sun through the zodiac is due to
Earths Revolution = Earth and Planets motion about the sun
Which universe model is vaster, the geocentric or the heliocentric?
heliocentric
Drawbacks to the Copernican model:
Orbits are round and not eliptical, orbital speed remains the same, still has epicycles (34), could not predict positions better than Ptolemy
This Dane made very accurate measurements of star and planet positions
Tycho Brahe
The appearance of a ___ in Cassiopeia in 1572 suggested a change in the heavens
Super Nova
Because Brahe detected little ___ in a comet, he showed that Aristotle was wrong
parallax
Big problems with the observations of astronomers until Brahe’s work:
imprecise; sporadic
This observatory on the Danish island of Hveen housed Tycho’s instruments
Uraniborg
How many telescopes were housed at Uraniborg?
0
Tycho proposed that planets orbited ___, and that ___ orbited ___
the sun, sun, the earth
He used Tycho’s Mars data to determine its orbital shape
Kepler
Instead of discarding the data when it didn’t fit the theory, Kepler was the first to discard
theory
Actual shape of a planetary orbit, as determined by Kepler
eliptical
The average distance between earth and the sun in miles
93 million miles
The average earth-sun distance is called an AU, or
Astronomical Unit
Kepler’s First Law
Orbit is elipse with sun at focus
Kepler’s second law
Planets sweep out equal areas in similar periods
Keplers third law
If earth is standard of measure, can calculate distance & measurement: P3 = A3
If P is unkown, A is distance. If Planet “X” is 4 times as far from sun as the earth, how long with it take to orbit?
4 cubed = 64
Square root of 64 is 8
8 earth years to orbit
Using Kepler’s third law, what is the distance from the sun in AU’s of a planet if its orbital period is 8 years
4 AU’s
Using a telescope, he was first to see Jupiter’s moons, he saw the phases of Venus, the moon’s imperfect features, observed sunspots, and found many more stars
Galileo
Galileo discovered the rings of Saturn - T/F?
False
One indication that the Aristotelians were wrong was the discovery that the four ___ orbited Jupiter, and not the earth
moons
This planets changing phases proves it orbits the sun
Venus
Surface features on these two objects suggested that celestial objects were not perfect
moon & sun
The telescopic discovery of many more stars than previously seen suggested that the Universe was ___
vast
Contrary to ancient belief, the stars were not confined to a narrow shell, but had ___
depth
Galileo was the only astronomer looking at the sky with a telescope in the early 1600’s - T/F?
False
After Galileo, telescope construction and star charting got ___
much better
These two astronomers saw and sketched the moon and sun before Galileo:
Scheiner & Harriot
Dark inner part of a shadow; not-so-dark outer shadow
umbra / penumbra
Faint, outermost atmosphere of the sun seen during a total eclipse
corona
These flame-like eruptions in the chromosphere can bee seen at totality
prominences
These appear in the sky during totality
planets & bright stars
Lunar eclipses are cause by the ___ falling on the
earths shadow, moon
The shadowy “bite” that is taken out of the moon is caused by the earths
shadow
Because earth shadow on the moon is fuzzy, this means we have an ___
atmosphere
Because the lunar silhouette during a solar eclipse is sharp, this means that the moon
has no atmosphere
The region around a planet where all the sunrises and sunsets are occuring
twilight circle
During totality, the red color of the moon is caused by
sunlight refracted through earth atmosphere then reflected back
Phase of the moon during a lunar eclipse
Full
When the moon is directly between the earth and sun we have this
conjunction
Phase of the moon during a solar eclipse
New
Intersection of new or full moon with earths orbital plane
Node (ascending & descending)
Why don’t we have a solar eclipse and a lunar eclipse every month
Orbit inclined 5 degrees to earth ecliptic
At 6-month intervals, eclipses occur; these are called
eclipse seasons
It’s possible to have a year with no solar eclipses - T/F?
False
In this kind of lunar eclipse, the moon is only slightly dimmed
penumbral lunar eclipse
During a solar eclipse, if we’re within the moons umbral shadow on earth, the eclipse is ___
total
If we’re outside the moons umbra but in the penumbra, we see a ___ eclipse
partial
If we’re outside the moons penumbra, we see ___ eclipse
no
This solar eclipse would be total, but moons at apogee
annular eclipse
Closest point in the moons orbit of the earth
Perigee
Farthest point in the moons orbit of the earth
Apogee
Three ways to safely observe the sun during a total solar eclipse
1) Telescopic Projection
2) Filters #14 arch welding glass or higher
3) Solar filters placed over telescopic objective
These “mini eclipses” are the result of an inferior planet passing between us and the sun
transits
In 1639 Jeremiah Horrocks observed the first transit of this planet
Venus
Observing transits helps us determine the ___ of the sun and of the transiting planets
size, diameter, orbital speeds, distances, atmosphere, exoplanets
Where would you need to be in order to see a transit of earth?
Mars or beyond
Why do more people see lunar eclipses than solar eclipses
Solar: Must be within narrow path of moons shadow
Lunar: Entire moon in earths shadow
When is the next transit of Mercury
2032
When is the next transit of Venus
2117
What is it about viewing the sun during a solar eclipse that makes it so dangerous
Staring at the sun without protection
When the moon passes directly between us and a planet, an asteroid or a star; or when a planet or asteroid passes directly between us and another planet, asteroid or star:
occulation
His “Pricipia” described how things move and how gravity works
Isaac Newton
Newton concluded that gravity works the same everywhere and is therefore
Universal
Measurement of the amount of matter in an object
Mass
The greater the masses of two objects, the ___ the gravitational force
greater
Given Fg=Mm/d2, Fg is the gravitational ___, M and m are the ___ & d is the ___
force, masses, distance
Given Fg=Mm/d2, if the product Mm is doubled, then Fg is ___, if distance between 2 objects is cut in half, the Fg is ___
doubled, quadrupled
Newton’s 1st law of motion says that is takes an outside ___ to change an objects inertia, a change in velocity and/or direction of travel of an object is known as ___
force, acceleration
Newtown’s 2nd law, F=ma, means that if you ___ the force, you increase the acceleration
increase (or decrease the moon)
Newtown’s 3rd law says that for every action, there’s an equal and opposite ___
reaction
What is the circular velocity for an object in low Earth orbit
18,000 mph
How fast must a rocket go to leave the earths gravity field
25,000 mph
He patented the first liquid-fueled rocket in 1926
Robert Goddard
First artificial satellite to orbit the Earth
Sputnik 1
First man in space
Uri Gagrin
First American in space
Alan Shepard
Why launch rockets from the east coast of Florida
Adds 1,000 mph boost from earth rotation
What two things must be in balance in order to maintain orbit?
Gravitational pull of the object you’re orbiting, inertial linear motion (gravity & inertia)
If a rocket exhaust has no air to push against, what does it push against to go?
Exhaust
Before people flew into space, Russia sent up ___ and America set up ___
dogs, monkeys & chimpanzees
First woman in space
Valentina Tereshkova (1963)
First American woman in space
Sally Ride (1983)
First black American in space
Guion Bluford
What was the name of the lunar manned mission project
Apollo
What Russian manned spacecraft has been used since the late 1960’s
Soyuz
First astronauts to walk on the moon
Neil Armstrong, Buzz Aldrin
Last astronauts to walk on the moon
Gene Cerian, Harrison Schmitt
