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unit 1 astronomy
mr. arnhold
Question | Answer |
---|---|
describe/define interplanetary dust | Dust particle in size, a small grain, generally less than a few hundred micrometers in size. Made of minerals and metals |
describe/define meteoroid | Are solid rocky & metallic objects in space that range in size from dust grains to small asteroids. Range in size between 100 um to 10 m across. |
describe/define asteroid | A larger version of a meteoroid. Generally considered to range from 10 m to 1000 km in diameter. Most are located within the asteroid belt between Mars and Jupiter. |
describe/define comet | Small body of ice, rock and dust. Range from a few to ten km wide. |
describe/define a moon or natural satellite | A celestial body that revolves around a body that is of greater mass. A planet generally has at least 10,000 times more mass than a moon that orbits it. |
is there a size range for an object to be called a moon- yes or no? | no |
what is the difference between a planet and a dwarf planet? | A dwarf planet has debris in its orbit |
describe/define galaxy | Is a large collection of hundreds of billions of stars in space, held together by their shared gravity. |
which galaxy do we live within? | The Milky Way Galaxy |
describe/ define galaxy cluster. which galaxy cluster are we within? | Gravitationally bound groups of several dozen galaxies, we are a part of the Local Group. |
describe/define supercluster. which supercluster are we within? | Made up of hundreds/thousands of galaxies, we are a part of the Virgo Supercluster |
describe/define universe | Is the sum total of all matter and energy |
why did people once think that earth was the center of the universe? | Because the sun, moon, planets, and stars appear to circle around the sky each day. |
state the 3 criteria needed for an object to be considered a planet | Orbits the sun, is massive enough to be spherical and has cleared its orbit of debris. |
what is the name of the theory that explains the formation of the solar system? | The Nebular Theory |
define/describe nebula | A cloud of interstellar gases |
what is thought to have started the solar nebula collapsing | The force of a nearby star explosion likely gave the gas a "push" that started its collapse |
as gravity caused the nebula to collapse, name two things that occurred to the material making up the cloud during this collapse | The gases began to rotate, and the gases got very tightly packed in the center of the nebula and began to heat up |
what is fusion? | The compression and heat of the material in the center of the nebula became so great that atoms began to "fuse" together |
what type of object now exists once fusion begins in collapsing nebula? | a star |
after the sun formed within the collapsing cloud, how is the planet form? | Small clumps of matter continue to collect more mass and grow larger |
what is planetesimal? | Small clumps of matter which are growing and on their way to becoming a full sized planet |
what is the frost line? | The particular distance in the solar nebula from the center where it is cold enough for compounds such as water, ammonia, methane, carbon dioxide, etc. To condense into solid ice grains. |
which set of planets, inner or outer, is differentiated (separated) into distinct layers such as core, mantle and crust | inner (mercury, Venus, earth & mars) |
what is a comet? where are they found in the solar system? | Cold, distant portion of the solar system is filled with billions of small, icy objects. Are located in wide disks beyond the orbit. |
define exoplanet | Planet outside of our solar system orbiting another star |