Astronomy Final Exam Review

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• Pseudoscience is a study that tries to explain scientific phenomenon. It does not follow the scientific method. An example would be astrology.

• Astronomy is the study of objects in space; astrology is the study of myths attached to stars’ locations in relation to Earth, and how this affects your personality.

• Kepler-3 laws of planetary motion

• Copernicus-Heliocentric theory of the universe

• Newton-3 laws of motion

• Galileo- perfected the telescope

• Brahe- greatest naked-eye astronomer of all time

• Doppler-Doppler effect named for him; used by Hubble to prove the expansion of the universe

• Stonehenge-astronomic calendar in England

• Objective- main lens-forms a small image

• Eye piece- used to magnify image; make it convenient

• Finder scope-larger field of view to find object before magnifying it with the full telescope

• Focus- brings the image into clear view

• The primary or main purpose of a telescope is to enlarge objects that are far away.

• The most powerful land telescopes are at the tops of mountains in order to decrease the effects of the atmosphere.

Reflecting telescope

• Radio telescopes pick up the invisible portion of the spectrum, whereas optical telescopes pick up the visible portion.

• In the future, telescopes will be multi-mirrored, and computer-aided.

• A prism is used to break white light into its rainbow of colors. This is used to determine the speed and distance of galaxies.

• Spectroscopes are used to break white light into colors, allowing astronomers to determine what elements are in a star, how far away objects are, and how fast they are moving.

• Violet has the shortest wavelength, red has the longest.

• Red shift- the object is moving away; blue shift, the object is moving toward

• Altitude- height above the horizon

• Azimuth- degrees around the sphere, away from north (0)

• Zenith-highest point; directly overhead

• Nadir- directly beneath you

• Horizon- where the sky appears to meet the land

• A 75---170

• B 45---90

• C 20---345

• D 5---270

• E 45---250

• F 20---45

• The big band theory states that the universe began in an explosion of matter and energy and has been expanding ever since.

• Universe- 13 BY The sun- 4.6 BY• The nebular theory states that the solar

system formed from a rotating cloud of gas and dust, which condensed to form the sun and all other solar system objects

Elliptical

Spiral

Barred Spiral

• Star- celestial object composed of gas, held together by its own gravity, and supported by nuclear fusion in its core

• Galaxy- very large collection of gas, dust, and stars orbiting a common center of mass

• Nebula- star nursery• Planetary nebula-remnants of a supernova

explosion• Supernova- how massive and supermassive stars

begin the end of their lives (after red giant or supergiant phase)

• Quasar- rare, starlike object that gives off radio waves as material is sucked toward a black hole

• Light year- the distance light travels in a year• AU-(astronomical unit)- 1AU= distance from Earth

to the sun

• Polaris- aka The North Star

• Sirius- brightest

• Alpha (Proxima) Centauri- closest

• Betelgeuse- In Orion, largest

• A star’s color reveals its surface temperature

• Stars are 75% Hydrogen and 25% Helium

• Apparent magnitude- brightness as seen by human eyes on earth; Absolute magnitude- intrinisic brightness; how bright it would be at 10pc

• White dwarfs=A

• Main sequence=D

• Red giants= C

• Supergiants=B

• Sun will never be=B

• Bluish main sequence= E

• Red main sequence= F

• Mercury-no atmosphere• Venus-hottest, spins backward• Earth-only one with life• Mars-red; polar ice caps• Jupiter-largest; 63 moons• Saturn-brightest ring system• Uranus-Green; tilted 90 toward the sun• Neptune-blue; great dark spot• Pluto-no longer a planet

• We are able to see planets because they are reflecting sunlight.

• As you increase the distance from the sun, you increase the orbit time

• New moon-dawn-sunset-none

• 1st quarter-noon-midnight-half (right side)

• Full moon-sunset-dawn-full

• 3rd quarter-midnight-noon-half (left side)

Earthshine

• Maria-lunar lowland filled by successive flows of dark lava

• Highlands-mountains

• Craters-circular remnants of impact

• Copernicus and Tycho are the names of craters (all craters are named after famous scientists)

• Gravity on the moon is 1/6 that of Earth.

• 1. core

• 2. radiative zone

• 3. convective zone

• 4. photosphere

• 5. chromosphere

• 6. corona

• Sunspots-magnetic storms on the sun’s surface. They appear dark because they are cooler than the surrounding surface.

• Sunspot cycle is an 11-year cycle of sunspot activity that corresponds with an increase in aurora activity.

• Lunar eclipsered moonS-E-M1 hourwith every full moon, somewhere on Earth

Solar eclipsemoon blocking the sunS-M-E2-11 minutes (totality)with every new moon (not total) somewhere on Earth

• The orbits of the planets are ellipses with the sun at one focus.

• No Need for Bode’s law

• Satellite-any object that orbits another (manmade vs natural)

• Meteor-an object in space that gives off light as it burns in Earth’s atmosphere

• Meteorite-the object strikes Earth’s surface

• Comets-objects beyond the orbit of Pluto; give off a streak of dust and ice when they get near the sun (tail)

• A meteor shower happens when Earth passes through the path of a comet, and the pieces of comet burn in Earth’s atmosphere.

• Gravity is the attraction between two objects that have mass.

• Inertia-an object in motion remains in motion…

• Rotation-spin on an axis

• Revolution-orbit around another object

• Perihelion-closest to the sun in orbit

• Aphelion-farthest from the sun in orbit

• Asterism-a named group of stars not identified as a constellation (ie. The Big Dipper and Little Dipper)