Karteikarten
Astronomy Ch1
Karten in diesem Stapel (59)
- 1Solar Systemthe sun and all the material that orbits it, including the planets, dwarf planets, and small solar system bodies
- 2Where is our solar system?little over halfway from galactic center on the edge of the galactic disk
- 3Milky Way Galaxyour galaxy as huge disk-shaped collection of stars (100 billion) and 1 of 2 largest among 40 galaxies (local group)
- 4Galaxy clustersgroups of galaxies with more than a few dozen members
- 5Galaxygreat island of stars in space containing from a few hundred million to a trillion stars arranged in giant chains & sheets with huge voids between them
- 6How are galaxies held together?held together by gravity and orbiting a common center
- 7Superclustersgigantic region of space where many individual galaxies and many groups and clusters of galaxies are packed more closely together than elsewhere in the universe
- 8Local Superclustersupercluster of galaxies to which the Local Group belongs
- 9Universesum total of all matter and energy encompassing the superclusters and voids and everything between them
- 10How old is the universe and why?14 billon yrs. old because we cannot see anything more than 14 billion light years away because light from such distant objects have not reached us
- 11Observable Universethe portion of entire universe that we can potentially observe from Earth (tiny portion of entire universe) containing 100 billion galaxies with as many stars as grains of sand on all the dry beaches on Earth
- 12Kilometer mile conversion1km=0.6 mile
- 13Astronomical unit (AU)Earth's average distance from the Sun; 150 million km used for distances in solar system
- 14Light-year (ly)distance that light can travel in 1 yr; 9.46 trillion kilometers used for distances of stars and planets
- 15How do we look back into time when observing the universe?the farther away we look into distance, the further back we look into time; see as it was regarding how many light years it takes to get to us
- 16Starlarge, glowing ball of gas that generates heat and light through nuclear fusion in its core
- 17Planetmoderately large object that orbits a star and shines primarily by reflecting light from star
- 18Object can only be a PLANET if:1. orbits a star
2. large enough for its own gravity to make it round
3. has cleared most other objects from orbital path - 19Moonobject that orbits a planet
- 20Satelliteany object orbiting another object
- 21Asteroidrelatively small and rocky object that orbits star and many orbit in a belt between Mars and Jupiter
- 22Cometrelatively small and ice-rich object along with small bits of rocky material "dust" that orbits star on elliptical/oval orbits
- 23Small Solar System Bodyan asteroid, comet, or another object that orbits a star but is too small to qualify as a planet or dwarf planet
- 24Star SystemStar (or more than 1 star) and any planets and other materials that orbit it
- 25Galaxy Groupssmall (up to a few dozen) collection of galaxies bound together by gravity
- 26Rotationspinning of an object around its axis, such as Earth's daily rotation around it's axis
- 27Orbit/Revolutionthe orbital motion of one object around another due to gravity; Earth orbits around sun each year
- 28Expansion of the Universeaverage distances between galaxies increasing with time
- 29Big Bangbirth of the universe and observed rate of expansion calculated that it occurred 14 billion years ago
- 30Why is gravity superior to overall expansion?force of gravity draws matters together into individual galaxies & galaxy clusters that do not expand while the universe is expanding
- 31How does gravity create stars and planets?gravity drives collapse of clouds of gas and dust to form stars and planets
- 32What happens when a star is born?gravity compresses material in a cloud until center becomes dense and hot enough to generate energy to nuclear fusion and lives as long as it shines with energy from fusion
- 33Nuclear Fusionprocess in which lightweight atomic nuclei smash together and stick/fuse to make heavier nuclei
- 34How does a star die?when it exhausts its usable fuel and blows much of its content back into space
- 35Supernovaetitanic explosions from dying massive stars
- 36What happens after a star dies and expels its contents back into space? (galaxies as cosmic recycling plants)returned matter mixes with other matter floating between stars in galaxy eventually becoming parts of new clouds and gas and dust from which new generations of stars can be born
- 37What 2 elements did the early universe have?hydrogen & helium
- 38How did additional elements come into the early Universe?manufactured by stars through either nuclear fusion that makes stars shine or through nuclear reactions accompanying explosions when stars die
- 39When was our Solar System formed?4.5 billion years ago
- 40How did stars accompany the formation of Earth when our Solar System formed?earlier generations of stars already converted 2% of galaxies original hydrogen & helium into heavier elements which is more than enough to make small rocky planets of Solar System including Earth
- 41Why was Pluto demoted to dwarf planet from it's original planetary status?1. overestimated mass-1/25 mass of mercury
2. 248 yr. Sun orbit more elongated in shape & tilted than any other planet
3. ice-rich composition similar to comet than planet
4. discovery of object slightly larger than Pluto (Eris)=not largest object in its region of Solar System - 42Astronomystudy of celestial objects and the physical laws that govern them
- 433 Scales of Universesize ratio- 1 : 10>7: >10>13
1. solar system: sun and planets
2. galaxy: giant pinwheel of stars
3. other galaxies clustered and spread to the observable limits of the universe - 44How much bigger is our galaxy compared to our solar system?our galaxy is 10 million times larger than our solar system
- 45Solar System Radius10>10 km; 10 billion km
- 46Most Abundant Elements1. Hydrogen +1 (89%)
2. Helium +2 (10%)
3. Oxygen +8 (<1%)
4. Carbon +6 (<1%) - 47What is the base unit for the distance of light?300,000 km/s
- 48Sunstar 10x larger than Jupiter composed mostly of atomic Hydrogen gas, producing energy by nuclear fusion in its center
- 49How far away is the Sun from the Earth?150 million km
- 50Jupitergas giant planet 12x larger than Earth primarily composed of molecular hydrogen
- 51Gas giant planets1. Jupiter
2. Saturn
3. Uranus
4. Neptune - 52Terrestrial planetsrocky planets like the Earth, Mercury, Mars, Venus with thin atmospheres and contain little/no hydrogen
- 53Kuiper Belt Objects/Trans-Neptunian Objectsicy (frozen water, or methane or ammonia) bodies in the outer solar system
- 54What are Kuiper Belt Objects/Trans-Neptunian Objects remnants of?remnants of solar system formation resulting in thousands of much smaller ones (down to 1 km diameter)
- 55Zodiacal Lightdust from evaporated comets and other particles between planets that scatter Sunlight
- 56What happens to comets as they approach the Sun?comets are vaporized as they approach the Sun but complete destruction takes many orbits/centuries
- 57What are the order of the planets in the Solar System?Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune - 58What 2 additional components can be found in Galaxies?interstellar gas and small solid particles/dust concentrated into nebulae and the light from hot stars makes nebular gas glow
- 59How is Earth moving in our Galaxy?Sun moves randomly relative to other nearby stars orbiting the galaxy once every 230 million years
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- Karteikarten am Astronomy Ch1, erstellt von aedeangel93 am 06/03/2014.
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