* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download The Universe - Lancaster High School
Lunar theory wikipedia , lookup
Chinese astronomy wikipedia , lookup
Definition of planet wikipedia , lookup
Hubble Deep Field wikipedia , lookup
Spitzer Space Telescope wikipedia , lookup
Tropical year wikipedia , lookup
Theoretical astronomy wikipedia , lookup
Outer space wikipedia , lookup
Astrobiology wikipedia , lookup
Aquarius (constellation) wikipedia , lookup
Stellar kinematics wikipedia , lookup
Solar System wikipedia , lookup
Corvus (constellation) wikipedia , lookup
Satellite system (astronomy) wikipedia , lookup
Star formation wikipedia , lookup
History of Solar System formation and evolution hypotheses wikipedia , lookup
History of astronomy wikipedia , lookup
Rare Earth hypothesis wikipedia , lookup
Planetary habitability wikipedia , lookup
Geocentric model wikipedia , lookup
International Ultraviolet Explorer wikipedia , lookup
Extraterrestrial skies wikipedia , lookup
Astronomical unit wikipedia , lookup
H II region wikipedia , lookup
Comparative planetary science wikipedia , lookup
Formation and evolution of the Solar System wikipedia , lookup
Extraterrestrial life wikipedia , lookup
Ancient Greek astronomy wikipedia , lookup
Dialogue Concerning the Two Chief World Systems wikipedia , lookup
Observational astronomy wikipedia , lookup
The Universe 8th Grade Science Modern Calendar -Year – time for Earth to orbit once around Sun. -Month – time for moon to orbit once around Earth. -Day – time for Earth to rotate once on axis. Early Astronomers Ptolemy -Greek -140 CE -Earth-centered solar system -Incorrect, but believed for over 1500 years Early Astronomers Copernicus -Polish -1543 -Sun-centered solar system -Afraid to publish theory -Copernican Revolution Early Astronomers Brahe -Danish -Late 1500’s -Most detailed observations so far -Earth-centered Solar system – but different… -Sun & moon orbit Earth -Rest of planets orbit Sun Early Astronomers Kepler -German -Brahe’s assistant -Disagreed with Brahe’s idea of solar system, but realized value of his data -Sun-centered solar system -Planets – elliptical orbits -3 laws of planetary motion Early Astronomers Galileo -Italian -1609 -One of the 1st people to use telescope -Discoveries: -craters & mts. on Luna -4 moons of Jupiter -sunspots on Sun -phases of Venus -House arrest Early Astronomers Newton -English -early 1700’s -Apple myth -Gravity -Explained why planets orbit Sun -Laws of Motion Modern Astronomy Hubble -American -1920’s -Galaxies beyond Milky Way -Universe expanding -Space telescope named in his honor Modern Astronomy Chandrasekhar -Indian-born American -1930’s-40’s -structure & evolution of stars -Chandrasekhar limit -White dwarfs -Nobel Prize in Physics Modern Astronomy Sagan -American -1960’s-70’s -lead search for “et” (SETI) -Contact -missions to Mars & other outer planets -coined term “nuclear winter” Modern Astronomy Hawking -British -1980’s-current -black holes emit radiation -universe infinite, theory of everything -ALS Electromagnetic Spectrum -Wavelengths of electromagnetic radiation -James Clerk Maxwell, Scottish (whoo-hoo),1852 Tools of Astronomy Optical telescopes -gather & focus VISIBLE LIGHT -reflecting (lenses)vs. refracting (curved mirrors) -on Earth – dirty windshield -in Space – MUCH better -Hubble ST Tools of Astronomy Nonoptical Telescopes -Radio telescopes–radio waves (VLA) -UV Telescopes -X-ray Telescopes -most in space due to atmosphere blocking. -all very powerful! Sun in Different Wavelengths Constellations -Regions of sky with recognizable star patterns -Navigation & track of time -Different cultures = different names/stories Measuring Distance in Space -Astronomical Unit (AU) – distance between Earth & Sun (1AU) -about 150 million km (93 million miles) -distance in solar system only! -Light-year- distance light travels in 1 year. -about 9.46 trillion kilometers! -distance in galaxies or between -Parsec – 3.26 light years -about the distance to the closest star. Doppler Effect -Occurs with sound & light waves -Sound – train passing by -Light -Redshift – object moving away, light looks redder -Blueshift – object moving toward, light looks bluer Moons -Satellite – natural or artificial – orbit around larger bodies. -moon- natural satellite. -All planets (except Mercury & Venus) have moons. -Luna – Earth’s moon. Formation of Luna -Composition similar to Earth’s mantle. -moon rocks from Apollo mission analyzed. ~4.6 bya, Mars-sized object hit Earth. -blasted part of mantle into orbit. -debris revolved, joined to form Luna. -Figure 2, page 111 Earth & Luna Moon Phases -Moon appears different due to changing positions. -waxing – sunlit area we see is getting bigger. -waning – sunlit area we see is getting smaller. -We always see same side of moon. -moon’s period of rotation=its period of revolution. -Figure 3, page 112 Solar Eclipse -Moon comes b/t Earth & Sun. -shadow of moon falls on part of Earth. -pg. 113 -Annular – moon farther from Earth. -disk of moon doesn’t completely cover Sun. -Total – moon closer to Earth. -disk of moon completely covers Sun. Lunar Eclipse -Earth comes b/t Sun & moon. -shadow of Earth falls on moon. -pg. 114 -Why don’t we see one every month? -moon’s orbit tilted about 5o. Comets -Ice, dust, rock particles -”dirty snowballs” -Formed in outer solar system. -”leftovers” from formation of solar system. -Oort Cloud – past Pluto -Kuiper Belt – past Neptune Asteroids -Rocky objects – orbit Sun -few km – more than 900 km! -Most orbit in asteroid belt -between Mars & Jupiter -Larger than 10 km in diameter = catastrophic global effects. Meteoroids, ors, ites -Small, rocky bodies – orbit Sun. -probably pieces of asteroids. -OIDS – In Space -ORS – Bright streak as it enters Earth’s atmosphere. -ITES – If it strikes the ground. Impacts -Planets/Moons with atmosphere = not as many impacts……..why???? -atmosphere slows down/burns up meteoroids. -Why are there not many impact craters on Earth? -weathering, erosion, plate tectonics - Earth Impacts -Impact - global catastrophe – every few hundred thousand years. -Impact – natural disaster – every few thousand years. -Meteor Crater, Arizona -1 mile across -550 ft. deep -formed 50,000 yrs. ago Torino Scale -Rates hazard level of space objects moving toward Earth. -numbered 0 – 10 -0 being no worries – 10 being worst case -also color coded -Developed by NASA http://neo.jpl.nasa.gov/torino_scale.html Journey Out of Our Solar System Stars -Composition – gases, mainly H & He. -Star’s Color tells us Temperature: -blue = hotter -red = cooler -Classified by how hot they are. -Orion Constellation -Betelgeuse: Red Supergiant -Rigel: Blue Supergiant Classifying Stars -Oh, Be A Fine Girl (Guy), Kiss Me! -pg. 35 – what does this mean??? -Which class stars are hottest? -Which class stars are coolest? “Life Cycle” of Stars -A Star is Born: -Stellar nursery(nebula) - huge cloud of gas & dust.. -Material compresses & heats up… -Begins to glow with radiation… -Temps in core reach 18 billion degrees F... -Begins nuclear fusion!!! Rosette Nebula Adulthood – Main Sequence -Longest lasting stage -Stable existence – no real turmoil -Core continues nuclear fusion -Our Sun Main Sequence Star Crisis – Old Age -How long a star live depends on its mass -smaller stars burn fuel less quickly = longer life. -bigger stars burn fuel more rapidly = shorter life. -All eventually run out & move along the cycle… Death Begins… -Outer layers “grow” & turn reddish in color -can get as large as the orbits of Mars or Jupiter -Called red giants or red supergiants -Remainder of death can go one of 3 ways… -Betelgeuse 3 Directions of Death… 1. Release of Outer layers – Sun 2. Nova – Stars bigger than Sun – explosion 3. Supernova – Most massive stars – Chuck Norris of explosions. -can be as bright as an entire galaxy In the Graveyard… 1. White dwarf – small, hot leftover center -stars the size of Sun or smaller 2. Neutron star – collapses under gravity – all particles are neutrons – extremely dense -stars 5-20 times mass of Sun -Pulsar – spinning Neutron star 3. Black Hole – gravity so immense that nothing can escape – not even light -stars 20 times or more massive than Sun Galaxies -Large groups of stars, gas & dust. -variety of shapes & sizes -largest contain more than a trillion stars! -billions of galaxies in known universe -Classified by shape. Spiral Galaxies -Central bulge & spiral arms -arms made of gas, dust & newer stars -Barred spirals – bar-shaped bulge -Milky Way, Andromeda -Sagittarius arm, Orion spur -Milky Way -Arms of Milky Way -Side view Elliptical Galaxies -Massive blobs of stars – look sphere or ovallike -VERY bright centers -very little gas & dust -Contain mostly OLD stars Irregular Galaxies -”Leftovers” – don’t fit into the other groups -shape sometimes distorted by nearby large galaxies Gas Clouds -Nebula – cloud of gas & dust -Found mostly in spiral galaxies -some reflect starlight, some absorb Part of the Eagle Nebula Horse head Nebula Cat’s Eye Nebula Star Clusters -Globular Cluster – older stars. -may contain up to a million stars -located in halo that surrounds galaxies -Open Cluster – closely grouped, younger stars -contain many bright, blue stars -a few hundred to a few thousand stars -located in spiral disk -Globular Cluster Omega Centauri Open Cluster - The Pleiades Quasars -Star-like sources of light – extremely far away -most powerful energy sources in universe -may be caused by super massive black holes in cores of some galaxies.