Transcript Slide 1
I. Measuring the Universe A. Distances in astronomy are very big. kilometers 1. On Earth: use __________________ (km): 384,000 Earth to Moon: ≈ __________________km Sun to Earth: 150,000,000 ≈ __________________km Sun to Pluto: 6,000,000,000 ≈ __________________km astronomical unit (AU) 2. In the solar system, use the ___________________ 1 AU Earth to Sun: ___ Sun to Pluto: 40 AU _____ Sun to nearest Star: _________AU 25,000 light year 3. To the stars and beyond, use the ___________________. 300 million Light travels at a speed of ______________meters per second The distance that light travels in a year is called a 6 trillion light year. 1 light year = _____________________ miles. Sun 8 light minutes Earth nearest star 4 light years Andromeda: a “close” galaxy 2 million light years M Moon 1.3 light seconds away B. A telescope is a tool that uses either: 1/ __________________ lenses mirrors 2/ __________________ to collect and focus light from places that are far, far away. time light Telescopes are _________ machines, because the _________ that comes to you through them left their star or galaxy past a long time ago. They allow you to look into the __________. more light it can The bigger the telescope, the __________ further back in time it can see. gather, and the ______________________ Galileo's Hubble Very Large Array II. What is in the Universe? A. Planets A body that orbits the Sun 1. planet - _____________________________________ and is large enough for its own _____________________________________ gravity to make it spherical _____________________________________ not enough mass Earth - enough mass -sphere of rock and metal ______________________________ -held together by gravity _______________________________ -revolves (orbits) around Sun _______________________________ http://video.nationalgeographic.com/video/player/science/spacesci/solar-system/solar-system-sci.html http://science.discovery.com/videos/space-school-solar-system.html http://www.metacafe.com/watch/1111454/formation_of_the_solar_sy stem_great_animation/ Earth from Voyager any object that orbits a planet 4. Satellites – _____________________________________ natural satellites moons – __________________________ X X a Mars-sized object 5. Earth's Moon formed when___________________ crashed into Earth billions of years ago. ___________________________________ The material reformed into the Moon. ___________________________________ Size of Moon compared to Earth: Diameters: Moon = _____ km ≈ Earth km scale: Earth Gravity on the Moon is only _______ of Earth's, because the Moon is _________________ and has less___________ . animation a Mars-sized object 5. Earth's Moon formed when___________________ crashed into Earth billions of years ago. ___________________________________ The material reformed into the Moon. ___________________________________ Size of Moon compared to Earth: Diameters: 3476 km ≈ Moon = _____ 12,756 km Earth 1 4 scale: Earth M 1/6 of Earth's, because Gravity on the Moon is only _______ mass the Moon is _________________ and has less___________ . smaller The Early solar system: http://www.metacafe.com/watch/1111454/formation_of_the_solar_sy stem_great_animation/ 2. Main components (parts) of the Solar System: 1/ gravity to hold planets A. The Sun provides: _____________________________ 2/ energy for Earth's weather __________________________ The Sun compared to Jupiter and Earth Sun Earth The Moon's orbit Jupiter B. The planets: Terrestrial planets close together ___________________ Jovian planets spread out ___________________ planet 1 2 3 4 5 6 7 8 Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune approx. distance from Sun in AU 0.4 0.7 1 1.5 5 10 20 30 Terrestrial ________ planets (Earth like) ___________ Jovian planets ________ (Jupiter like) ______________ 1. Terrestrial planets: - Mercury, Venus, Earth and Mars ________________________________________________ - closest to Sun ________________________________________________ - metal sank to core because it is denser than rock ________________________________________________ - are denser and have solid surfaces ________________________________________________ 2. Jovian planets (the gas giants): -Jupiter, Saturn, Uranus, Neptune ________________________________________________ -larger and further from Sun ________________________________________________ -mostly liquid and gas (hydrogen and helium) ________________________________________________ - are less dense and have no solid surface ________________________________________________ -all have rings and many moons ________________________________________________ object smaller than planet 3. Asteroid – stony/metallic __________________________________________ Texas largest – Ceres the size of ________ dwarf - a ____________ planet sphere - enough mass gravity made it a __________ irregularly shaped most - much smaller _____________ Mars and Asteroid belt- region between the orbit of ________ Jupiter ______________ where most asteroids are - divides ______________ and ________ planets S http://video.nationalgeographic.com/video/player/science/spacesci/solar-system/solar-system-sci.html http://science.discovery.com/videos/space-school-solar-system.html http://www.metacafe.com/watch/1111454/formation_of_the_solar_sy stem_great_animation/ 4. Eris Dwarf planets - Pluto __________ and __________. rock and _______ ices - mostly _______ a region beyond found in the Kuiper belt – _______________________ Neptune that is a source for short-period comets ______________________________________________________ Sun dirty 5. comets – a _________snowball - made of rock and ice 1-100 km diameter: ___________________ As a comet nears the Sun, the ices turn to _______. gas tail This creates a huge ___________ that always points away from _____________________ the Sun. The closer the comet longer gets to the Sun, the ______________the tail becomes. Sun _________ tail when _________ dirty 5. comets – a _________snowball - made of rock and ice 1-100 km diameter: ___________________ As a comet nears the Sun, the ices turn to _______. gas tail This creates a huge ___________ that always points away from _____________________ the Sun. The closer the comet longer gets to the Sun, the ______________the tail becomes. tail Sun longest _________ tail when closest _________ 6. Assorted space junk: sand to _______-sized dime a. meteoroids- _______ solids that orbit the Sun b. meteors – meteoroids that enter Earth's atmosphere burn up and ___________________ streak across the sky - often creates a _________________________ lands on Earth's surface c. meteorite – a meteor that ________________________ Tunguska, Siberia: comet exploded above the surface Meteor Crater, Arizona The "face" in Canada The meteor that killed the dinosaurs 65 million years ago struck on the edge of the Yucatan Pennisula. gravity map of area: Why is it easier to find meteorites in Antarctica? Largest meteorite ever found –Namibia Desert A car hit by a meteorite in Peekskill, NY Through the roof of a Chicago apartment times during year when 7. Meteor showers- ________________________ meteors are seen more often ________________________ –Explanation: -comet leaves trail of dust and rocks in its orbit _________________________________________________ -Earth crosses the orbit of the comet _________________________________________________ -comet pieces enter atmosphere and burn up _________________________________________________ x x where showers occur x = ___________________ S E billions stars C. Galaxy - a collection of _______________________, gas and __________ dust ______ held together gravity by ____________ Types: football 1. Elliptical – shaped like a _________________ basketball or a ________________ flat disk with "arms" 2. Spiral – shaped like a _____________ bar across the center - sometimes has a _____ distorted shape due to 3. Irregular – ____________________ collisions with other galaxies ____________ Ex: The Whirlpool Galaxy: The bright areas are where the most stars are located. Ex: a barred spiral: NGC 1300 Ex: M87 – An elliptical galaxy Ex: Irregular galaxies NGC 4490 - irregular The Milky Way – our galaxy spiral galaxy -a ____________________ 2/3 out along an arm -our solar system is about _______ 200 billion stars -contains over ___________________ black hole -has a gigantic __________________ at center top view: side view: 100,000 _________ light years x disk bulge x our solar system x = ___________________ spiral arms View of the Milky Way from Earth's surface. You are looking into the disk of the galaxy. Red lights of a star party. The Great Galaxy in Andromeda: Similar to the Milky Way. D. The Universe 100 billion -contains over _________________ galaxies e m p t y s p a c e between galaxies -with _______________________ Big Bang -expanding ever since the ____________________ The Hubble "Ultra Deep Field" The light from some of these galaxies took billions of years to reach us. One grain of rice held at arm's length…. Ex: (not to scale) The diagram below shows how one object fits within another. Put the correct symbol next to each word. _____ = galaxy _____ = planet _____ = universe _____ = solar system smaller ---------------------------------- bigger galaxy solar system___________ planet universe __________ __________ ___________