unit 1 the universe
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Unit 1 The Universe. Mrs. Morgan 8th Grade. Big Idea:. The sun is one of billions of stars in one of billions of galaxies in the universe. Unit 1 Lesson 1 Structure of the Universe. Our Place in Space. Universe - space & all the matter & energy in it . - PowerPoint PPT PresentationTRANSCRIPT
Unit 1 The UniverseMrs. Morgan8th Grade
Big Idea:•The sun is one of billions of stars in one of billions of galaxies in the universe.
Our Place in Space
•Universe-space & all the matter & energy in it.•Galaxy- a large collection of stars, gas, & dust• There are an estimated 100 billion galaxies
in the universe.
M i l k y w ay g a l a x yE a r t h
U n i v e r s eS o l a r s y s t e m
Unit 1 Lesson 1 Structure of the Universe
Types of Galaxies• Spiral galaxies are shaped like
pinwheels. They have a central bulge from which two or more spiral arms extend.
• Elliptical galaxies look like spheres or ovals and do not have spiral arms.
• Irregular galaxies appear as splotchy, irregularly shaped “blobs.” They are very active areas of star formation. http://library.thinkquest.org/C0110277/images/galaxies.gif
Unit 1 Lesson 1 Structure of the Universe
What Makes Up the Universe?
•Solar system- the collection of large & small bodies that orbit our central star, the sun.• Planet-spherical body that orbits the
sun.
Unit 1 Lesson 1 Structure of the Universe
Terrestrial Planets
• Terrestrial Planets- rocky, dense, and relatively small.•Mercury, Venus, Earth and Mars
http://ut-images.s3.amazonaws.com/wp-content/uploads/2008/04/mercurycomparison.jpg
Unit 1 Lesson 1 Structure of the Universe
•Gas giant planets - have thick, gaseous atmospheres; small, rocky cores; and ring systems of ice, rock, and dust.
• Jupiter, Saturn, Uranus, and Neptune.
Unit 1 Lesson 1 Structure of the Universe
Small Bodies in the Universe
•Moons- orbit most of the planets. Earth has only one moon, but Jupiter has more than 60.• The solar system has other small bodies, including • Dwarf planets• Comets• Asteroids• Meteoroids
• http://home.earthlink.net/~meshellwg/w/www/images/comet.jpg
Unit 1 Lesson 1 Structure of the Universe
Measuring the Universe• Distances between most objects in the universe
are so large that astronomers measure distances using the speed of light.
•Light-year -the distance that light travels through space in one year.• Light travels through space at about
300,000 km/s, or about 9.5 trillion kilometers in one year.
Unit 1 Lesson 1 Structure of the Universe
Reach For The Stars!•Star - large celestial body that is composed of gas & emits light. • Most stars are composed almost entirely
of hydrogen and helium.• Stars emit light and vary in brightness,
size and temperatures.
Unit 1 Lesson 1 Structure of the Universe
http://www.le.ac.uk/ph/faulkes/web/images/stars.jpg
You’re a Shining StarHow is star brightness measured?
• Apparent magnitude -measure of a star’s brightness as seen from Earth.
– Luminosity- actual brightness of a star.
• Absolute magnitude -measure of how bright a star would be if the star were located at a standard distance.
Unit 1 Lesson 2 Stars
Too HOT to Handle• Surface temperatures of Stars
are measured by their COLORCOLOR SURFACE TEMPERATURE (˚C)
Blue Above 25,000
Blue-white 10,000-25,000
White 7,500-10,000
Yellow-white 6,000-7,500
Yellow 5,000-6,000
Orange 3,500-5,000
Red Below 3,500
Unit 1 Lesson 2 Stars
Stars differ greatly in size
• White dwarfs - Very small stars have about the same radius as Earth, which is approximately 0.01 solar radius.
• Giant stars - Very large stars, typically have sizes between 10 and 100 times the sun’s radius.
• Supergiants - Some rare, extremely large stars have sizes of up to 1,000 solar radii.
Unit 1 Lesson 2 Stars
A Star Is Born
http://dsc.discovery.com/convergence/hubble/hits/gallery/garden4_lrg.jpg
What is the life cycle of a star?
• Stars form in nebulae.
• Nebula -large cloud of gas and dust. It is composed mainly of hydrogen and helium, with small amounts of heavier elements.
Unit 1 Lesson 3 The Life Cycle of Stars
Birth of a Star•Nuclear fusion –high temp & pressure cause two or more low-mass atomic nuclei to form a heavier nucleus.
Unit 1 Lesson 3 The Life Cycle of Stars
The Lightweights• Low-mass stars
– Giants-large red stars due to star’s outer atmosphere expanding after active fusion ends.
– White dwarf -hot, dense core of matter that remains from the collapse of a low-mass star. It is about the size of Earth.
Unit 1 Lesson 3 The Life Cycle of Stars
The Heavyweights• High mass stars
– Supergiant-produces heavier elements like carbon
– Supernova -gigantic explosion in which a high-mass star collapses, throwing its outer layers into space. But its core remains.
– Neutron star -small, incredibly dense ball of closely packed neutrons.
– Black hole -invisible object with gravity so great that nothing, not even light, can escape it.
Unit 1 Lesson 3 The Life Cycle of Stars
A Graphic Display•H-R diagram -illustrates this pattern is called the Hertzsprung-Russell diagram, or.
Main sequence -region of the diagram where stars spend most of their lives.
Unit 1 Lesson 3 The Life Cycle of Stars