Key Terms - Astronomy Flashcards

Terms Definitions
moon cycle
coasting universe
expands forever
formulas(2nd law)
F=ma; P=f/a
synodic month =
29.5 days
Shapes of the moon
The chromosphere (literally, "color sphere") is a thin layer of the Sun's atmosphere just above the photosphere, roughly 2,000 kilometers deep.
the cause of cassini's division
wobble in Earth's rotational axis.
Earth rotating on its axis
taught of a spherical earth
a zodiacal constellation between Gemini and Aries, containing the bright star Aldebaran also called the Bull
dark ages
atoms exist but stars don't
holds some of the largest telescopes
range of visible light
400nm - 700nm
man-made equipment that orbits around the earth or the moon
Colliding spirals form ellipticals
Jane Charlton (PSU)
an instrument that separates light into colors and makes an image of the resulting spectrum
oval shaped, like a flattened circle
physical power or strength possessed by a living being:
the study of planets, stars, galaxies and other objects found in space
kepler's first law states that planets move in _____ paths in space
Lunar eclipse
What type of eclipse is this?
lighter colored mountains on the moon
lunar highlands
The force of attraction between all masses in the universe.
Solar Flare
occur above active sunspots. Large quantity of gas. Emit X-rays and ultraviolet radiation. Last a short time
temper foam
to absorb shock in airplane seats
copernican revolution
the critical realization that the earth is not at the center of the universe
Saturn's _______ is the most impressive
ring system
geocentric model
Aristotle and Ptolemy's idea that planets moved around the Earth on circular paths and constant speeds
line drawn from north to south creatine east and west halves
the outermost region of the sun's atmosphere
Momentum is defined as _________.
mass times velocity
Has the probes Viking I & II
The distance ladder:What method is used to find the distance to furthest stars?
Spectroscopic parallax
inertness, esp. with regard to effort, motion, action, and the like; inactivity; sluggishness.
a quasar
emits large amounts of radio energy, but photographically appears to be a
single point of light much like a star
solar flares
brief expulsion of large quantities of gas and charged particles produced by the rapidly changing magnetic fields around sunspots; a flare occurs above an active sunspot and emits high-energy x-rays and ultraviolet radiation
What do all objects in the solar system have?
Quantum Mechanics
the physics of the very small, quantities which appear
continuous on the relatively large scales of our senses come in tiny discrete units, or
quanta. The consequences for physics and astronomy are profound.
piece of space rock that fell through the atmosphere
Person hired by Tycho Brahe to work out the mathematical details for his version of the geocentric universe who eventually discovered that planets orbited in ellipses rather than perfect circles and this became the first law in his famous 3 Laws of Planetary Motion
known for it's great blue spot (big hurricane)
Population II Stars
1. contain lesser quantities of heavier elements
2. composition is thought to match the composition of the young nucleus
3. found in globular clusters, galactic halo nucleus
When a planet stops moving forward in the normal direction and appears to"back up
the motion of an object around another object (a year)
Forms of Erosion: (3)
Glaciers, Ground Water and Waves
collapses and explodes
Eventually a star ___ and ___.
how far have we drilled into earth's crust?
Chunks of ice and dust whose orbits are usually very long, narrow ellipses.
large group of stars, dust, and gas held together by gravity; can be elliptical, spiral, or irregular
angular diameter
angle formed by lines extending toward you from the opposite edges of the object and meeting at your eye
What International Astronomical Union function was maintained at the University of Cincinnati?
The minor planet center
Edmond Halley
"Halleys comet"
went through historical records. Fund records of exact dates of when comet seen and when it dissapeared. Many happened 75 years apart. Reconstructed the orbit of Halleys comet. Died before ever getting to see it.
having or representing the earth as a center:
visible light
splits into the rainbow of color, the light that our eyes can see, ranging from about 400-700nm.
steady state theory
theory that suggests that the universe always has been the same it is now. the universe always existed and always will
supernova type II
results from the rapid collapse and violent explosion of a massive star. A star must have at least 9 times, and no more than 40-50 times the mass of the Sun for this type of explosion. It is distinguished from other types of supernova by the presence of hydrogen in its spectrum. Type II supernovae are mainly observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies.
distance of the star
Knowing the luminosity and apparent brightness of a star allows calculation of the:
Solar Eclipse
Event that occurs when the moon comes in between the sun and the earth and the shadow of the moon falls on part of the Earth
Time it takes for Earth to orbit the Sun once. (Approximately 365.25 days long!)
as earth moves around the sun in its yearly orbit, the constellations we see in the sky at night do not change throughout the year
Spiral Arms
Bright because of O & B type stars
galactic clusters
molecular clouds
glowing emission nebulae
Density 5-10% greater than in between arms
only persist for around 10,000,000 years
wave theory of radiation
electromagnetic waves travel at the speed of light
Evolutionary Track
The path that a star follows across the H-R diagram as it evolves through its lifetime
an immense cloud of gas and dust in interstellar space
solar day
the amount of time that passes between successive appearances of the Sun on the meridian; the amount of time from high noon to high noon; varies in length throughout the year
3rd planet from the sun the only plent known to support life because of its liquid water and atmosphere; Earth's protected atmosphere maintains temperature
ring galaxy
A galaxy that resembles a ring around a bright nucleus. Believed to be the result of a head-on collision of two galaxies. (p. 297)
caused by the pull of the moon on the Earth.
total solar eclipse
occurs at perigee, when the moon is closest in its orbit to Earth.
center of the galaxy
in the direction of the constellation sagittarius
radio metric dating - measurment of various a__ and i___.
We can determine the age of a rock through careful a___ of the proportions of various a____ and i_____ within it.
atoms, isotopes.
analysis, atoms, isotopes.
how are molecules formed
when two or more atoms share electrons
How often does Haley's comet come around?
Once every 76 years
Kuiper Belt
a region of the solar system that is just beyond the orbit of neptune and that contains small bodies made mostly of ice
the figure of the moon in its first or last quarter, resembling a segment of a ring tapering to points at the ends
define a neap tide
a tide that occurs when the difference between high and low tide
mass of spiral galaxies
6. To get the mass distribution with radius in a spiral
a. We observe the orbital velocities of stars in the galactic disk at different angular distances from the center.
b. We assume that the orbits of these stars are circular and all located in a single plane in which the bulk of the mass
of the galaxy is also located.
c. We assume that the mass in the disk of this galaxy is
essentially evenly distributed around the ring at each
radial distance from the center in the disk.
d. Taking an estimate of the distance to the galaxy and the measurements in (a) together with the assumptions (b) and (c), we can build a computer program that applies Newton's law of gravitation to obtain a consistent model for the radial distribution of mass in the disk of the galaxy.
phases of the moon
varying amounts of the lighted moon as seen from earth
Which of the following is correctly ordered from MOST energetic to LEAST energetic?
Ultraviolet, blue, yellow, infrared, radio
order of the planets from the sun
mercury, venus, earth, mars, jupiter, saturn, uranus, neptune (MVEMJSUS)
Heliocentric model of the Universe
model which places the sun at the center of the universe
what two type of motion are associated with stars
actual motion and apparent motion
Low altitude (morning, evening and winter months)
If the shadow is really long, describe the altitude of the Sun.
How do you tell between a core-halo or lobe radio galaxy
Depends on the view
-Classified depends on position with respect to the lobes and jets
What is the general fate of comets?
ejection from SS, break up, volatiles exhaused, collision
What causes the phases of the moon?
they are caused because we see the lighted side of the moon from different angles
Which of the following best describes a meteor
A small piece of debris that ENTERS the Earth's atmosphere
Which of the following represents a case in which you are not accelerating?
Driving in a straight line at 60 miles per hour
What are some basic properties of the terristrial planets?
close to the sun, small in size and mass, rocky, high density, slow rotation, few moons
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