Astronomy Midterm 2 Flashcards

Terms Definitions
lunar eclipse
too proud
extremely massive star
change in velocity
Solar Prominences
releases glowing hydrogen
roman name for Poseidon
elevation angle of Pole star
Channels in the lunar surface.
absolute magnitude
another name for luminosity
composition. co2 95.3%, nitrogen 2.7%
major star groups, 88 regions
refracting telescopes
telescopes that use only lenses
electromagnetic spectrum
arrangement of electromagnetic waves according to their wavelengths
nucleus of a radioactive atom disintegrates. electron is released but nucleus has less energy than initial nucleus. but turns out thanks to pauli that it is the neutrino that is taking away the missing energy.
19th brightest; blue giant. Several hundred parsec away.
27 concentric spheres (all revolving around the earth)
- National Aeronautics and Space Administration
- To understand and protect our home planet, To explore the Universe and search for life, and To inspire the next generation of explorers
the reflective property of a non-luminous object
Amount of material in a body
Granulation is the most direct evidence of solar convection
Granulation is the most direct evidence of solar convection
The inner layer of the sun's atmosphere that gives off it's visible light
a cloud of interstellar gas and dust
Which planet is also known as Aphrodite?
What electromagnetic wave can be felt as heat?
angular momentum
circling momentum or turning momentum in which the object is either spinning or moving along a curved path
icy nucleus which evaporate and gets blown into space by solar wind =
What does fusion produce?
energy in the sun/stars
a device built to observe distant objects by making them appear closer.
micro waves
2nd largest wavelenght, cook food, electricty
Which of the following planets has not
had volcanism and tectonics in the recent past?
apollo asteroid
pass through earths orbit, possibly dangerous
An arch like projection above the solar photosphere often associated with a sunspot
one of Jupiter's large moons; the largest moon in the solar system - larger even than the planet Mercury
the science that deals with the material universe beyond the earth's atmosphere.
Spectral classification
-A star's spectrum gives its temperature
-Temperature: hot -> cold
-Color: Blue -> red
true or false
Black body radiators are generally hot
black hole
a theoretical massive object, formed at the beginning of the universe or by the gravitational collapse of a star exploding as a supernova, whose gravitational field is so intense that no electromagnetic radiation can escape.
Basalts are thought to make up most the
the grand unification epoch
forces except gravity are unified
seventh planet from the Sun; is large and gaseous, has a distinct bluish-green color, and rotates on an axis nearly parallel to the plane of its orbit
Winter Constellations
visible during the winter; sun covers them during the summer
mass/ volume; the mass per unit volume of a substance under specified conditions of pressure and temperature
summer solstice
longest day of sunlight for the northern hemisphere
refracting telescope
optical telescope that has a large convex lens that produces an image that is viewed through the eyepiece
The part of a shadow surrounding the darkest part.
tendency for an object to resist a change in motion
white dwarf
IS a star. made of electron-degenerate matter. it can be half the mass of the sun.
What evidence do astonomers look for on planets to determine if life could exist there?
Liquid Water
Prime Meridian
a line that runs through Greenwich, England. longitude of zero degrees
the state of an object in which physical processes balance each other so that its properties or conditions remain constant
Where are the Red Giants like Betelgeuse located?
Upper Right
an imaginary line that runs from north to south, passing through the observer's zenith
All planets shine by what kind of light?
The slow change in the direction of Earth's axis of rotation

One cycle takes approximately 26,000 years
astroid belt
belt of rock that orbits the sun usually between mars and jupiter
greenhouse effect
The trapping of heat by a planet's atmosphere
order of the planets
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.
red shift
an object in the universe that is moving away from earth.
Waxing Moon
The phase of the Moon when an increasing amount of the Moon's near side is sunlit
reflecting telescope deficiencies
mirror precision can be tricky, viewer has a bit less light as some of it is blocked
Hubble's law
the farther away a galaxy is, the faster it is moving away from us
new moon
moon phase that occurs when the Moon is between Earth and the Sun, at which point the moon can not be seen because its lighted half is facing the Sun and its dark side is facing Earth
leap year
calendar year with 366 rather than 365 day.; Our current calendar (the Gregorian calendar) has a leap year every 4 years (by adding February 29), except in century years that are not divisible by 400.
increase in the phase of a moon or planet.
How many stars are in binary star systems?
about half
the darkest part of a shadow during an eclipse
a small body made up of rocky material & ice that occurs in the Kuiper Belt & Oort cloud
tidal tail
A long streamer of stars, gas, and dust torn from a galaxy during its close interaction with another passing galaxy. (p. 296)
a person skilled in an applied art; a craftsperson.
partial lunar eclipse
when the moon passes partly into the umbra of the earth
Universal time, from BG +6 hours when it is not dst
Planetary Differentiation
the process early in the life of each planet whereby dense elements sink inwards and light elements rise up.
Which of the following is not an
energy source for the Sun at present but
has been in the past and will be in the
gravitational potential energy
Free Fall
the motion of an object when the only force acting on it is gravity
North and South Celestial poles
Earth's north and south poles projected onto the Celestial Sphere.
When a bus makes a sudden stop the passengers lurch forward as a consequence of ____ law
Newton's 1st
Define: Orbital Period
The time taken for a given object to make one complete orbit around another object, calculated with respoect to the stars.
Explain the two major (gravity-related) heat sources that made the early, forming Earth so hot that it was completely molten throughout. Describe the current heat source that keeps Earth's interior partially molten.
While the Earth was forming, the energy from impacts converted gravitational energy to heat while energy from differentiation converted friction into heat as well. Differentiation is the separation of substances with different densities, and within the Earth's core, the constant circulation of molten materials caused friction. Currently, radioactive decay is responsible for the continued heating of the Earth's core through the abundance of Uranium acting as a giant fuel rod.
Four proofs the Earth Rotates
Coriolis effect, Star trails, Day and night, Foucault's Pendulum
What is the ecliptic?
The path the Sun appears to trace around the celestial sphere each year.
Death of a Star
after fuel runs out a star will slowly fade away, become a white dwarf, a neutron star, or a black hole
Newton's Universal Law of Gravitation
Orbit vs free fall; force of gravity= (constant x mass of two objects) / distance from center of object
Wien's Law
If you know peak λ of a hot body, you can determine its temperature--used to get the temperatures of stars
What happens in the sun's interior?
dense core made of hydrogen, fusion here, light created
Also called the thermonuclear core
Why don't eclipses occur every month?
Because of the tilt of the moon's orbit.
What is the relationship between temp and luminosity in stars?
They have a direct Relationship. The hotter the star, the brighter it shines.
What happens to the earth in both June and December?
The winter solstice occurs around December21 each year and it is the shortest day of the year in the Northern Hemisphere. The summer solsticce occurs around June 21st eaach year and it is the longest year in the Northern Hemisphere.
what has been done in an attempt to detect intelligent life in space?
project SETI aims radio receivers towards millions of stars and trying many other frequencies besides those which are produced by hydrogen, we also send radio messages throughout the universe, this wave is preveland in the entire cosmos
How were the moon and the maria on the moon formed?
•The collisional ejection theory of the moon's origin holds that the proto-earth was struck by a Mars-sized protoplanet and that debris from this collision came together to form the moon
•The low density lava on surface cooled to form crust.
•Large asteroids hit the moon to form large basins which were filled with lava to form maria
how can crater counts tell us the age of planetary surface. why is the moon more cratered than the earth
After the era of heavy bombardment, the cratering rate was (and is) pretty much constant. Thus, the number of craters per unit area can be used to approximately date the surfaces. The Moon’s surface hasn’t tectonically changed in over 4 billion years, so it carries the scars of all the impacts on its surface, while the Earth basically resurfaces itself within ¼ of a billion years.
absorbs photons
3rd quarter
symbol for Zinc
Natural satalite of earth
stars in the universe
a huge collection of stars
Sputnik 1
the first artifical satellite
north 80
alpha- Markab Beta- Scheat
pegasus was ordered by Bellerophon to fly to mt olympus to be a god , this angered zeus so he got an insect to sting pegasus and buck off Bellerophon who died from the fall an pegasus went to greatness as the "thundering horse of Jove" who carries lighting bolts for zeus.
the result of electromagnetic radiation passing through a prism or grating so that different wavelengths are separated.
gamma rays
have the shortest wavelength
Constellation known as a mighty hunter
the planet closest to the sun
Define and explained galaxies- a person
The process occuring when photons bounce off a polished surface is called:
Who published the first astronomical observations made with a telescope?
non-luminous chunks of rock before they enter Earth's atmosphere. Friction from atmosphere causes them to burn and as they streak across sky they are METEORS (luminous object).

When meteor does not burn up completely and impacts earth it is a meteorite
known as dirty snowballs, chunks of ice and dust.
the ability to detect fine detail, provided by larger telescopes, `
a device for directly viewing a spectrum
the change in direction of a propagating wave (light or sound) when passing from one medium to another
A stone meteorite that contains no chondrules.
Magnitude Scale
The astronomical brightness scale; the larger the number, the fainter the star.
Years till Sun will die
3.5 bilion years
refractor telescope
Has lenses that concentrate light energy like glasses.
Reasoned that objects fall to Earth because Earth and the objects are attracted to each other due to gravity. The force of attraction depends on the masses of the objects and the distance between them.
critical density
the cosmic density corresponding to the dividing line between a universe that recollapses and one that expands forever
cosmological constant
a "vacuum pressure" force associated with empty space and effective only on very large scales. It's influence increases as the universe expands. May be the major factor controlling the expansion.
Escape trajectory
7 mi/s and greater will escape
The _______ or outer planets are large, gaseous, and have low densities.
-Subatomic particle with no charge and very little mass
-Very abundant in the Universe
-1 inch of lead will stop an X-ray, but stopping a neutrino would require a slab of lead >1 light-year thick!
operational definition
a statement that describes how particular variables are to be measured, or how a term is to be defined
band around the sky extending 9 degrees above and below the ecliptic
a massive object orbiting a star, like the sun. A true planet has cleared the neighborhood around its orbit & has enough mass so that gravity forms it into a spherical shape.
is north of Syene along the Earth's curved surface and shadows are cast, measuring the angle of the Sun in _______at noon on the Summer Solstice when it was overhead in Syene lets you measure the circumference of the Earth, at _________ sun 7 12/60 degrees south of overhead, casting shadow, can calculate the arc from _____ to syene
SN 2006gy
The supernova SN 2006gy is the brightest and most energetic stellar explosion ever recorded and may be a long-sought new type of explosion;About 238,000,000 light years
sunspot cycle
periodic variation in the number of sunspots that occurs approximately every 11 years
Density Waves
Spiral arms of galactic disks are patterns or pressure waves which move through the disk, which increase the density of matter at their crests. Also triggers star formation
light year
the distance light travels in one year
keplers 3rd law
orbits distance to sun are perportional
telescope size
bigger is better because more light gathering power, more resolving power
The smaller a planet, the smaller its ___________ force.
Solar Eclipse
Occurs when the moon travels directly between the earth and the sun, temporarily blocking the sun from earth
a curved piece of plastic or glass that, depending on it's shape either disperses or concentrates light rays as they pass through it
very-long-baseline interferometry (VLBI)
a method of connecting widely separated radio telescopes to make observations of very high resolution.
E0 galaxy
Elliptical galaxy that is the most spherical
getting bigger (as does the moon from new moon to full moon)
part of the galaxy where you would find galactic clusters
refracting vs reflection
refracting: using lenses to focus light from distant objects. Reflecting: uses a curved primary mirror to gather light to a secondary mirror that lies in front of it.
Circumstellar Disks
Flattened spinning clouds of dust and gas
primitive meteorites
Meteorites formed at the same time as the solar system about 4.6 billion years ago. These can be found from the inner asteroid belt and are stony. Those found around the outerbelt are carbon rich.
Trans Neptunian Objects
TNO's, SSSB, Icy objects orbiting Sun beyond orbit of Neptune
This planet has the moon Io which is the most volcanically active body in the solar system
Transit Photometry
Planet goes in front of the sun, blocks light
mars surface
1. Olympus Mons - Shield volcano - largest mountain in the solar system
2. Valles Mariners - Enormous Valley that runs along the equator of Mars
3. Polar Icecaps - Frozen water and carbon dioxide
4. Evidence of water flow in the past.
5. Red dust on the surface is Iron Oxide (rust)
In terms of plate tectonics Mars is described as having starting the
Radius for a Rock so that gravity makes it a sphere
1000km radius
international space station
orbits in outer space and provides space for astronauts to work and live
stellar parallax
the most direct way of measuring a star's distance
retrograde rotation
when a planet rotates from east to west
Which of the following defines density?
mass divided by volume
Binary Stars
Pairs of stars that orbit around their common center of mass.
Heavier Elements are...
much smaller fraction of the normal mass of the universe
TF An F-type star would have a larger habitable zone than does our Sun
Types of observations by ancient Chinese
meteor showers, eclipse predictions,comets.
On an H-R diagram, one plots
C. luminosity versus temperature
On an H-R diagram, one plots
A. temperature versus mass
B. radius versus luminosity
C. luminosity versus temperature
D. radius versus mass
E. distance versus luminosity
the point in the orbit of a heavenly body, esp. the moon, or of a man-made satellite at which it is farthest from the earth.
Density wave theory
model of spiral arms and how they maintain stability
*like a traffic jam
how was Pluto discovered?
because of Neptunes deviation, in 1930 by Clyde Tombaugh
How much time will it take for light from the Sun to reach Jupiter?
40 minutes
star clusters
a group of stars created from a single cloud of interstellar gas at the same time
local apparent solar time
sundial time; position of the real sun's position relative to an observer's local meridian
Aberration of Starlight
Proves that the Earth is moving in orbit.
The lowest path of the Sun; it rises and sets at the most extreme south of due east.
winter solstice
How do scientists determine the age of the solar system.
radiometric dating of meteorites.
source of Earth's magnetic fields
the core of liquid rotating generating a magnetic field with Van Allen belts
What is the name of the theory that is currently used to describe the formation of the solar system?
condensation theory
Kepler's Third Law
Amount of time a planet takes to orbit the Sun, P, is related to its orbits size
daily eastward drift of the sun
<1° per day, reflects the Earth's annual orbit around the sun
How does Interstellar dust do to the light of a star?
Interstellar dust dims (extinction) and reddens the starlight.
when is a star born?
when the contracting gas and dust from a nebula become so dense and hot that nuclear fusion stars
a solar mass of .08
a brown dwarf is a low mass M star
"Ockham's Razor" is the principle that:
A theory should be as simple as possible.
cause: Sun's rays heat the Earth's surface
effect: water on the Earth's surface evaporates
Why do we call dark matter "dark"?
it emits no radiation that we have been able to detect
what is the temperature range on the moon
100 degrees C - 175 degrees C
Explain how the Earth's rotation, combined with the tidal bulges from the Moon, result in the Moon's orbital distance from the Earth slowly increasing over time.
The pull on the Moon by the Earth is not equal throughout because of the direction of the Earth's rotation and the "leading" tidal bulges. The unequal gravitational force adds energy to the initial rotation of the Moon around the Earth, causing the gradual moving away of the Moon from the Earth, called lunar recession.
It was once thought our solar system had over 20 planets before the definition of planet was last modified in 1852. Explain what all of these extra planets were and why they were demoted from planet status.
The definition used to be a body that orbits a star shines by reflecting the star's light and is larger than an asteroid- they found hundreds of icy worlds, some quite large, in a donut shaped region called the Kuiper belt.- they found they were asteroids and if they named all them we would study 135000 planets.
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