Complete List of Terms and Definitions for Astronomy Key Terms Day - Part

Terms Definitions
earth our planet
red shift farther
Earth's natural satellite Moon
Jupiter the largest planet
Mars pressure 1/100 of earths
1 nm 10^-9m, 10 A
au distance between earth and sun
Nasa National Aeronautics and Space Administration
S-waves - only travel though solids
meteor meteoroid that comes to earth
what planet is heavily createred mercury
Angular momentum mass times velocity times radius
Satellite Any object that revolves around another object.
Spectroscopic Parallax mainsequence star and knowing temperature lets you estimate luminosity
Meteorite Space rock hitting the Earth's surface.
Zenith Point directly overhead for and observer
synodic period the interval between successive occurrences of the same configuration of a planet as seen from Earth
galileo first measurement of speed of sound
false TF a gravitationally bound universe, with omega greater than 1, will expand forever.
Kepler German astronomer who first stated laws of planetary motion (1571-1630)
globular cluster a comparatively older, spherically symmetrical, compact group of up to a million old stars, held together by mutual gravitation, that are located in the galactic halo and move in giant and highly eccentric orbits around the galactic center.
carbon dioxide dissolved into ocean water and precipitated out as carbonates (e.g. limestone)
What is the name given to 2H? Deuterium
Speed How fast or so something is moving.
Blackbody A perfect absorber and a perfect emitter of EM radiation; idealized object, no reflection or scattering. Think of a hole in the side of a box.
plate a section of the Earth's lithosphere pushed about by convective currents within the mantle
Hertzsprung-Russel diagram graph that tells absolute magnitudes and temps
Asteroid Fragments of rock or material larger than 100 meters that orbit the sun, often called "minor planets." The largest Ceres is 933 kilometers in diameter
SETI the organized effort to find life elsewhere in the universe
Zodiac Set of constellations that the sun moves through
Fusion the forcing together of 4 hydrogen atoms to make Helium and lots of energy
Rotation spinning, represents the length of a day
chain reaction Neutron released during the fission process strike other nuclei causing them to split.
amino acids the Murchison meteroite in Australia was found to contain ____ ____
matter can emit, absorb, transmit or reflect light
spectral sequence The arrangement of spectral classes (O, B, A, F, G, K, M) ranging from hot to cool. (p. 113)
inertia inertness, esp. with regard to effort, motion, action, and the like; inactivity; sluggishness.
Pluto Now is considered to be a dwarf planet.
yes Is there a small magnetic field near Mercury
Which region if the Sun has the highest temperature? core
Regolith What is the soil-like layer on the moon's surface?
Io Moon with a very active surface; over 100 active volcanoes.
polar orbit satellite orbit that moves around the North or South pole in a circular orbit
umbra the very darkest part of the moon's shadow
Parallax is: The apparent change in position of nearby objects when viewed from different points.
ecliptic the path the sun takes across the celestial sphere each year, as seen from earth
Astronomy The study of the moon, stars, and other objects in space.
Planets must... -orbit sun
-have enough mass to be round
-dominate it's orbit
When does the Artic Circle expeirence 24 hours of sunlight? Summer Solstice
electromagnetic radiation energy that can travel through space in the form of waves
Mercury the smallest planet and the nearest to the sun
space station is a large artificial satellite on which people can live and work for a long period
tropical year period of time between one vernal equinox to the next
pressure the amount of force exerted per unit area of a surface
what is a reflecting telescope? reflects light using mirrors
parsec a unit of distance equal to that required to cause a heliocentric parallax of one second of an arc, equivalent to 206,265 times the distance from the earth to the sun, or 3.26 light-years.
Day the length of time it takes for a planet to make a complete rotation on its axis
transit when a star is in transit, it is passing over your celestial meridian (not all stars rise and set - circumpolar)
Newton's 1st law An object moves at constant velocity unless a net force acts to change its speed or direction.
Star A glowing ball of gas held together by its gravity and powered by nuclear fusion
perihelion The point in its orbit where a planet is nearest the Sun.
solstice point or time at which the sun is farthest from the equator
Constellation A group of stars that forms a pattern resembling a familiar object, character, or animal, and that changes position throughout the year because Earth moves.
winter solstice - when the southern hemisphere is t____ towards the s__ and it recieves most d___ sunlight tilted, sun, direct
Processed meteorites are believed to
have originally been part of relatively
large objects (parent meteorite bodies,
like planetesimals or the largest
asteroids) which were differentiated;
they are mainly composed of 		either rock or metal
equatorial mounting device which allows you to point a telescope towards celestial objects
the apparent daily motion from east to west Diurnal motion
elliptical galaxies a galaxy shaped like a rounded or flattened ball.
Nebula A large amount of gas and dust in space, spread out in an immense volume.
Newton Law 3 every action brings an equal and opposite reaction
Continuous Spectrum A spectrum which contains all of the visible colors
heliocentric universe a model of the universe with the sun at the center, such as the Copernican universe
Main Sequence Star at the point in the life cycle which it is fusing hydroen nuclei into helium nuclei
starts fusing hydrogen to helium A protostar becomes a main-sequence star when it ___.
on the top right of the H.R. diagram are the _ stars red giant
solstices the 2 days of the year which the sun is farthest north and south of the equator
uranus and neptune colors blue green due to methane. the tempuratures are too cold for chemicals (they freeze) that give jupiter and saturn their orange yellow colors
apparent brightness the brightness of a star as seen from earth
proof the earth rotates Coriolis Effect, Star Trails, Day & Night, Foucault's Pendulum
mercury atmosphere too small and too close to sun to have one
proton proton chain This is the name of the chain reaction that turns hydrogen into helium in the Sun.
At every step of the process, energy is released.
What happened when the temperature dropped when the universe was 1 second old deuterium nuclei began to form, starting the process of helium production
The center of the nucleus of the Galaxy a massive black hole
What is the largest cyclical perturbation of the Moon called? When was it discovered? The largest cyclical perturbation of the Moon actually has a name, the Evection. It was discovered by Hipparchus, and Ptolemy mentions it prominently. These ancient astronomers did not know why it occurred, but they did detect its effect on the position of the moon.
Why aren't small asteroids spherical in
shape? 		The strength of gravity on small asteroids is less than the strength of the rock.
Whats the equations for the Hubble Relation? Velocity= H0 Times Distance
H0= 55Km/sec/Mpc
For every million parsec away it lies, a galaxy;s speed increases by 55 km/sec.
Without the greenhouse effect in our atmosphere, B. the Earth's average temperature would be forbiddingly cold
Without the greenhouse effect in our atmosphere, A. we would not have to worry about any ecological problems.
B. the Earth's average temperature would be forbiddingly cold.
C. the amount of nitrogen and oxygen would be much less
D. the ice in our poles would have melted long ago
E. the whole Earth would be completely submerged.
What happens to the rotation of a molecular cloud as it collapses to form a star? The rotation rate increases and results in a disk of material around a protostar
What are the four ways that star producing shock waves are produced Supernova explosions, birth of very hot (o and b) stars, cloud collisions, spiral arms of galaxy.
If an object has a spectrum that is red-shifted, then the object is Moving away from the observer
the theory of expansion allows for the possiblity that the universe is closed, open or flat
What causes the change in the seasons on Earth? The earth's axis and revolution around the sun
When the Earth, Moon, and Sun are in a line a spring tide occurs (most extreme tides).
Since there is no atmosphere on the moon, what can its temperature range from? the sun can heat the moon to 127C and without sunlight the temperature can drop to -173C