Complete List of Terms and Definitions for Astronomy Test 15

Terms Definitions
gravity 10ms¯²
homogenous same throughout
meteoroid falling or striking
Lupus constellation: the wolf
Speed of Light 300000 Km/Sec
HCl symbol for Hydrochloric acid
Larger means... volume, not mass
Eclipse one celestial body obscures another
Local Noon Star/ Sun straight overhead
mercury almost no atmosphere, heavily cratered, difficult to study because it is so near the sun
core the center of an object
Tail What is behind the comet
epicycles theoretically caused by difference in planet speed
Mars's mantle and lithosphere are __________ when compared to that of Earth. thicker
electromagnetic radiation Radiation consisting of oscillating electric and magnetic fields, namely gamma rays, X rays, visible light, ultraviolet and infrared radiation, and radio waves.
Speed Rate at which object moves. S=d/t
corona the outer layer of the sun
hydrogen fusion main energy source in stars
When is the spring equinox? March 21st
claudius ptolemy theory explained retrograde motion, the planets traveled along small circles that move on the larger circles of the planets' overall orbits, almagest, most of our knowledge of greek astronomy comes from this
sinister threatening or portending evil, harm, or trouble; ominous:
Radio Galaxy Very bright, often giant, elliptical galaxy that emits as much or more energy in the form of radio wavelengths as it does wavelengths of visible light.
rich clusters -lots of clusters, 10s of thousands
-nearest one is virgo cluster
-very large elliptical galaxies in them
gravitational lensing The magnification or distortion (into arcs, rings, or multiple images) of an image caused by light bending through a gravitational field, as predicted by Einstein's general theory of relativity.
Temperature +253 degrees F in sunlight; -387 degrees F at night
revolution the motion of any astronomical object around another astronomical object
conjunction Planets are close to the sun, inferior-in between and superior on the other side, they will rise at sunrise
Magellan the first planetary spacecraft to be launched from a space shuttle. Revealed no evidence on Venus of plate
tectonics, such as operates with such profound effect on Earth. Volcanoes have left their marks on 85% of Venus, with lava plains, lava domes, large shield volcanoes, and extremely long lava channels. The rest of the surface is covered with ranges of deformed mountains.
Asteroids solid rocky or metallic bodies that orbit the sun
five Any osculating orbit can be described by ____ parameters.
mass how long a star lives depends on...
Zenith The point directly above an observer's head (i.e. 90 degrees above the horizon). In the planetarium, the Zenith is the highest point on the dome.
pulsar a rapidly spinning neutron star that produces radio waves
space probe a spacecraft that carries scientific instruments that can collect data, but has no human crew
Newton's ________ second law states that the acceleration of an object is directly proportional to the net applied force and inversely proportional to the object's mass— that is, the greater the force acting on the object, or the smaller the mass of the object, the greater its acceleration. Thus, if two objects are pulled with the same force, the more massive one accelerates less. If two identical objects are pulled with different forces, the one experiencing the greater force accelerates more.
Kepler's
Newton's
Heliocentric model Sun centered, planet revolve in elliptical orbits, sun at one focus.
The orbital point of closest approach to the Sun? Perilhelion
subgiant a giant star smaller and lower in luminosity than normal giant stars of the same spectral type; evolve to become giants
Starburst galaxies.. are often associated with a galaxy that is colliding with another galaxy
orbit Earth's path as it revolves around the sun
spicules dynamic jet of about 500 km diameter in the chromosphere of the Sun. It moves upwards at about 20 km/s from the photosphere. They were discovered in 1877 by Father Angelo Secchi of the Vatican Observatory in Rome.
inferior planet planets closer to the Sun than Earth
The Moon Earths only satellite. It is slightly younger than Earth (4.5 billion years old). This planet was the result of a collision between the Earth (Mark I) and aMars-size object named Orpheus. Earth in turn stole the iron core of Orpheus and the excess material was caught in the Earth's orbit. This satellite was then bombarded with meteorites, giving it it's craters. Some of the impacts broke through the crust to create maria (lava that flowed out of the center and hardened). This satellite has no atmosphere because it's gravity cant hold gasses. It also rotates on an axis around Earth at 5 degrees and it fully revolves around the Earth in 27.3 days. This satellite is leaving Earth at 1 1/2 inches per year.
What is the contact binary close binary star system? Common envelope.
Earth's Period of Revolution 365 and 1 fourth days
H-R Diagram Plot of a stars light & temp.
astronomy the study of the moon, stars, and other objects in space.
Chromosphere a layer of somewhat thinner gases at 60 000 degress C that make up the inner atmosphere of the Sun; lies outside of the photosphere
Spiral Galaxies 1. Ones with large, bright nuclei stars and tightly would spiral arms
2. Ones with very small, dim nuclei and open sprawling arms
force needed to bind protons and neutrons together, only force that can overcome electromagnetic repulsion
- only works at very small distances 		strong forcr
galaxy a huge group of single stars, star systems, star clusters, dust, and gas bound together by gravity
neap tide a tide with the least difference between low and high tide
equinox period of equal days and nights; the beginning of spring and autumn; Ex. vernal/autumnal equinox; ADJ. equinoctial
solar system orbital resonances Small perturbations at opposition usually happen at different places along the orbit, effects average out over long times
tide the periodic rise and fall of the waters of the ocean and its inlets, produced by the attraction of the moon and sun, and occurring about every 12 hours.
Celestial Sphere Imaginary globe where Earth is at the centre and provides an easy way of describing position of objects in sky
Binary stars pair of stars that orbit around their common center of mass
constellation group of stars that forms a pattern in the sky that looks like a familiar object (Libra), animal (Pegasus), or character (Orion)
Where is our Sun located in the galaxy? The disk
red giant When stars run out of hydrogen fuel and there is only helium left, they will expand and form a _________
Composition of Saturn: Core: heavy element
2nd layer: liquid hydrogen, much less so than Jupiter
3rd layer: Gaseous hydrogen
-Stronger winds than Jupiter
Lunar phases Patterns of lit and unlit portions of the Moon that you see from Earth
polaris what is the name of the star found above the north pole of the earth?
Unbound orbits paths that bring an object close to another object just once
Molecular Clouds 103 to 105 atoms/cm3 include from a few hundred to a few tousand masses temps as low as 10k
50 The Sun is __ times greater than the Earth's diameter.
Heliocentric a model of the solar system that is centered on the Sun, with the earth in motion about the sun, our actual model.
terrestrial planets a collective name for the four planets closest to the Sun and within the astroid belt
Astronomical unit Distance for the sun to earth (93 million miles or 146 million km)
Absolute Brightness how bright the star would appear at a standard distance, this is a fair way to compare stars
mass of sun 1/3 of a million times greater than earth
the sun's visible oscillations are the combines effect of about 10 million separate (sound) notes. they can be used to look deep inside the sun 10 million separate notes
Constellations a group of stars that forms a shape or pattern in the celestial sphere
How do starts move in our solar system ___ r___ At random
ellipse A type of oval that happens to be the shape of bound orbits. An ellipse can be drawn by moving a pencil along a string whose ends are tied to two tacks; the locations of the tacks are the foci (singular, focus) of the ellipse.
Proxima Centauri Which star is he second closest to the Earth?
What powers the sun? A violent collision of 2 protons, initiating the proton-proton fusion reaction
People (last name only) Copernicus Discovered that planets move around sun
Kepler's First Law The orbit of a planet around the sun is an ellipse with the sun at one focus. The higher the number the more elongated the ellipse is.
Body Thermometer Pill made by NASA to monitor the core body temperature for astronauts during space flight
Electric Field a field that is able to exert a force on a charged object, whether at rest or moving
T v. J comparison- distance to sun T = closerJ = further
What was the first flight to land on the moon and when? Apollo 11, July 20th
What is an asterism? Give some examples. A grouping of stars less formally-defined than constellations, but still widely known. Ex: Big Dipper, Little Dipper, Great Square of Pegasus, Winter Triangle
Night and Days we observe on Earth are due to Rotation of it's axis
The terrestrial planets are made almost entirely of elements heavier than hydrogen and helium. According to modern science, where did these elements come from? They were produced by stars that lived and died before our solar system was born.
rise towards the east and set towards the west How do stars rise and set?
A Type I Supernova (carbon detonation) is... The explosion that results when a white dwarf exceeds a mass of 1.44 solar masses.
rises 6 hours, falls 6 hours How do tides change over the course of a day?
What are some major planet characteristics that most of them have in common? 1. all planets orbit the sun in the same direction2. they orbit in the same plane (through the sun's equator ... except pluto3. orbit in nearly circular orbits (except mercury, mars, pluto)4. rotate in the same direction they revolve (counter clockwise) ... except venus, uranus, pluto5. most planets spin quickly(except mercury, venus, pluto)
After he had discovered his Laws of Planetary motion, Kepler: tried to determine the causes of that motion.
Relative to the age of the universe, how old is our solar system? It is about one-third the age of the universe.