Big idea # 5 – Earth in space in time Galaxy, stars, planets, solar system, distance and size, and exploration The origin and eventual fate of the Universe still remains one of the greatest questions in science. Gravity and energy influence the formation of galaxies, including our own Milky Way galaxy, stars, the planetary systems, and Earth. Humankind’s need to explore continues to lead to the development of knowledge and understanding of the nature of the Universe.
Benchmark Number & Descriptor • SC.8.E.5.1 Recognize that there are enormous distances between objects in space and apply our knowledge of light and space travel to understand this distance. • SC.8.E.5.2 Recognize that the universe contains many billions of galaxies and that each galaxy contains many billions of stars. • SC.8.E.5.3 Distinguish the hierarchical relationships between planets and other astronomical bodies relative to solar system, galaxy, and universe, including distance, size, and composition. • SC.8.E.5.4 Explore the Law of Universal Gravitation by explaining the role that gravity plays in the formation of planets, stars, and solar systems and in determining their motions. • SC.8.E.5.5 Describe and classify specific physical properties of stars: apparent magnitude (brightness), temperature (color), size, and luminosity (absolute brightness). • SC.8.E.5.6 Create models of solar properties including: rotation, structure of the Sun, convection, sunspots, solar flares, and prominences. • SC.8.E.5.7 Compare and contrast the properties of objects in the Solar System including the Sun, planets, and moons to those of Earth, such as gravitational force, distance from the Sun, speed, movement, temperature, and atmospheric conditions. • SC.8.E.5.8 Compare various historical models of the Solar System, including geocentric and heliocentric. • SC.8.E.5.9 Explain the impact of objects in space on each other including: • 1. the Sun on the Earth including seasons and gravitational attraction • 2. the Moon on the Earth, including phases, tides, and eclipses, and the relative position of each body. • SC.8.E.5.10 Assess how technology is essential to science for such purposes as access to outer space and other remote locations, sample collection, measurement, data collection and storage, computation, and communication of information. • SC.8.E.5.11 Identify and compare characteristics of the electromagnetic spectrum such as wavelength, frequency, use, and hazards and recognize its application to an understanding of planetary images and satellite photographs. • SC.8.E.5.12 Summarize the effects of space exploration on the economy and culture of Florida.
Copernicus – Heliocentric view of the solar system • Ptolemy – Geocentric view of the solar system • Galileo – First to use telescopes to observe the solar system and moon. Discovered evidence for the following: • Jupiter’s four moons revolve around the planet • Venus goes through phases similar to that of Earth’s moon • Halley - Recognized Halley’s Comet as a periodic comet in the 18th century • Herschel – Discovered what would be know as Uranus, the first new planet in modern times • Hertzsprung – Graphs relating temperature and brightness of stars • Hubble- Discovered that the farther away a galaxy is, the faster it is moving away from us • Kepler – Showed that orbits are elliptical shaped not circular • Newton – Invented reflection telescope. Identified two factors that keep planets in orbit: • Inertia • Gravity • Russell – Graphs relating temperature and brightness of stars; together they formed the Hertzsprung-Russell Diagram Who’s Who in Astronomy
How Did It All Start? Origins of the Universe
Origin of the Universe Steady-State Theory Big Bang Theory
The Future… • Oscillating Universe Hypothesis – • This hypothesis has to do with the future of the universe. • Universe will continue expanding until it runs out of fuel, and everything becomes cold and dark. • Universe will contract causing the opposite of the Big Bang Theory. • All matter will be pulled back together by gravity resulting in an enormous black hole.
Knowledge Check • 1. Which is the most widely accepted theory of how the Universe came about? • 2. During the Steady State Theory, what is happening to the galaxies? • 3. When did the Universe form? • 4. What is one theory explaining the future of our Universe?
Knowledge Check • 1. Which is the most widely accepted theory of how the Universe came about? • The Big Bang Theory • 2. During the Steady State Theory, what is happening to the galaxies? • Every galaxy is being replaced by new ones. • 3. When did the Universe form? • According to the Big Bang Theory, the universe was formed 10-15 billion years ago. • 4. What is one theory explaining the future of our Universe? • The galaxies will continue to expand. Once they run out of fuel, gravity will pull them back together, eventually creating a massive black hole.
What’s Out There? STRUCTURES IN THE UNIVERSE
galaxies spirals elliptical irregular
STRUCTURES in the UNIVERSE • GALAXIES – • Galaxies are large scale groups of stars that are bounded together by gravity. • Size of a typical galaxy is 100,000 light years in diameter. • Roughly 100 billion stars are contained within a galaxy. ** Galaxies are moving away from each other as space expands
IRREGULAR SHAPE GALAXY • No real structure • Irregular galaxies are unevenly distributed throughout the universe. • Least common • Two of the closest to the Milky Way • Large Magellanic Clouds • Small Magellanic Clouds STRUCTURES in the UNIVERSE
ELLIPTICAL SHAPE GALAXY • Smooth ellipse shape • Flattened or deflated football • Contains trillions of stars • Little rotation if any • Little dust/gas so new stars cannot form STRUCTURES in the UNIVERSE
SPIRAL SHAPE GALAXY • Disc shaped • Bulge in the middle with arms that spiral out and rotate around the center of the galaxy • Pinwheel shaped • Center has massive cloud of stars, gas, and dust. • Milky Way Galaxy – where our solar system is located STRUCTURES in the UNIVERSE
Milky Way Galaxy • The Milky Way has a diameter of about 100,000 light years. • The nucleus is 2000 light years thick. • Our sun is located 30,000 light years from the nucleus. • It takes the Sun 200 million years to make one rotation around the center. STRUCTURES in the UNIVERSE
QUASARS - is short for Quasi-stellar radio source. • Very bright but distant galaxies with a black hole in the center • Will photograph like a star • Gas around black hole heats up and shines brightly • Contains a large red shift • Has a variable energy output Quasar 3C273 STRUCTURES in the UNIVERSE
Knowledge Check • 1. What galaxy do we live in? • 2. How many classifications of galaxies are there? • 3. Identify 2 characteristics of Elliptical galaxies. • What do all types of galaxies have in common?
Knowledge Check • 1. What galaxy do we live in? • The Milky Way galaxy • 2. How many classifications of galaxies are there? • 4 – spiral, elliptical, irregular, and QUASARS • 3. Identify 2 characteristics of Elliptical galaxies. • Smooth ellipse shape • Little dust/gas so new stars cannot form • What do all types of galaxies have in common? • They all contain large groups of stars, gas, and dust which areheld together by gravity
CLASSIFICATION of STARS • Size (largest – smallest) • Supergiant • Fills space from Sun to Jupiter • Giant • Medium • Example – Sun • White Dwarf • Neutron Star • Temperature • Red - coolest • 3,500 C • Example – Betelgeuse • Yellow-White - medium • 6,000 C • Example – Sun • Blue-White - Hottest • 50,000 C • Example – Rigel STRUCTURES in the UNIVERSE
CLASSIFICATION of STARS • Magnitude (Brightness) • Apparent • The amount of light received on Earth from a star. • Absolute • Actual Brightness: How large and hot a star is in relation to other stars. • Identified from the Hertzsprung-Russell Diagram • Systems • Binary • 2 stars • Triple-Star • 3 stars • Example – Proxima Centauri • Eclipsing Binary • One star blocks the other from view. • Detected by gravitational pull on other star STRUCTURES in the UNIVERSE
LIFE CYCLE OF A STARA closer look NEBULA • Stars are made (born) in giant clouds of dust and gas. • Gravity pulls together the gas and dust. • Once the particles are close enough, nuclear reaction can start. • A Star is created – Protostar“baby star”
LIFE CYCLE OF A STARA closer look PROTOSTAR • As the gravitational energy increases, the temperature rises. • A protostar takes about 100,000 years to reach the main sequence.
LIFE CYCLE OF A STARA closer look STAR • Nuclear fusion begins. • Releases massive amounts of energy • The star then stays almost exactly the same for a long time (about 10 billion years for a star like the Sun). • The star begins to run out of fuel. • Large mass = short life span • No more energy is released from the core. • Core shrinks while outer part expands.
LIFE CYCLE OF A STARA closer look RED GIANT or SUPER GIANT • Eventually, the hydrogen (the fuel for the nuclear fusion) in the center of the star will run out. • Gravity will pull in the center of the star while the outside floats away • This is what will happen to our sun but not for billions of years. • If the star is a massive star, it will become a Supergiant. • Antares – a Red Giant
LIFE CYCLE OF A STARA closer look NORMAL SIZE STAR WHITE DWARF BLACK DWARF • Formed from a Red Giant • Size of Earth, mass of sun • No fuel • Glow from left over energy – can glow for millions of years. • White Dwarf stops glowing. • The star is dead.
LIFE CYCLE OF A STARA closer look GIANT SIZE STAR SUPERNOVA NEUTRON STAR/ PULSAR • An explosion of a giant or supergiant star • Massive star explodes and throws its outer layers into space. The Crab Supernova Remnant • The center of a collapsed star after a supernova • All the stars particles are neutrons. • Smaller and denser than a white dwarf • If the Neutron star is spinning, it is called a Pulsar.
LIFE CYCLE OF A STARA closer look GIANT SIZE STAR BLACKHOLE • Forms from the most massive stars • If the center of a collapsed star is 3x more massive then the sun, the star will contract due to massive gravitational pull. • Light cannot escape due to gravity. • X-rays are given off by stars and dust sucked into a black hole (allows black holes to be found).
Birth and Death of Stars - Summary White Dwarf and Planetary Nebula Collapsing cloud Sun-like stars A new star Supernova Remnant and Neutron Star Red Giant Massive stars
CONSTELLATIONS • Groups of stars which form pictures in the sky • There are 88 constellations recognized by astronomers today. • Different constellations are seen at different times of the year due to the earths rotation. • Southern/Northern hemisphere will see different constellations. • Example: Ursa Minor (Little Dipper) • Polaris – north star • Last star in the handle • Early travelers tracked their position by using Polaris. STRUCTURES in the UNIVERSE
Knowledge Check • 1. Explain how color indicates the temperature of a star? • 2. Compare absolute and apparent magnitudes. • Arrange the following stages in the order in which they occur: red giant, white dwarf, nebula, main sequence. • What type of star is the sun?
Knowledge Check • 1. Explain how color indicates the temperature of a star? • Red, yellow = Cool • Blue, White = Hot • 2. Compare absolute and apparent magnitudes. • Apparent magnitude = The amount of light which we receive from a star • Absolute magnitude = The actual amount a light a star gives off • Arrange the following stages in the order in which they occur: red giant, white dwarf, nebula, main sequence. • Nebula, Main sequence, red giant, white dwarf • What type of star is the sun? • Main sequence
STRUCTURES in the UNIVERSEThe SUN • Parts of the Sun • Core • Atmosphere • Photosphere • Chromosphere • Corona
PARTS OF THE SUN • Core • Center of the Sun • 15 million degrees Celsius • Atmosphere • 3 layers • Photosphere • “Light” • 5000-8000 °C • Inner Layer • Makes light that reaches Earth • Part we see and look at • Chromosphere • “Color” • 5000-10000 °C • Middle layer of Sun’s atmosphere • Reddish glow • Visible during a total solar eclipse • Atmosphere • Corona • “ Crown” • One million °C • Outer layer of the Sun’s atmosphere • Special telescope needed to view • Sends out electrically charged particles = Solar winds • When solar winds hit gas molecules in the Earth’s atmosphere at the poles, it causes the molecules to glow = Auroras.
FEATURES OF THE SUN • Solar Flares • Explosions • Burst of energy from the Corona • Causes magnetic storms • Disrupts radio, TV, telephone signals • Prominences • Huge arch of erupting gas • Comes from the chromosphere • Links sunspots • Sunspots • Areas of cooler gas in the sun’s photosphere • Look dark because they are cooler • Amount of them is not constant • Affect Earth’s temperature Solar flare Prominence Sun Spot
Life cycle of our sun We are now here.
Knowledge Check • 1. How many sections of the Sun’s atmosphere is there? • 2. What is the difference between a prominence and a solar flare? • How long does it take light from the sun to reach the Earth?
Knowledge Check • 1. How many sections of the Sun’s atmosphere is there? • 3 • Photosphere “light” • Chromosphere “Color” • Corona “Crown” • 2. What is the difference between a prominence and a solar flare? • Prominence is an arc of gas (both ends are on the sun). • Solar Flare is energy/gas shot out into space (leaves the sun). • How long does it take light from the sun to reach the Earth? • It only takes about 8 minutes.
Origin of the Solar System Tidal Theory Condensation Theory • Huge clouds of ice, etc. beyond the gas planets are the main source of comets. • Asteroids formed between inner and outer planets.
LOCATION Heliocentric Geocentric • Sun is at the center of our solar system. • Copernicus theorized. • Earth is at the center of the revolving planets. • Ptolemy theorized.
PLANETS Revolve Rotate
PLANETS around other stars • Can be detected by the effect of the planet’s gravity on the motion of the star it revolves around • The smaller the planet, the harder it is to detect due to a lower force of gravitational pull. • Astronomers are currently researching better ways to see these planets directly. • Glare from other stars block our views http://www.nasa.gov/mission_pages/hubble/science/fomalhaut.html Are There More Planets Out There?
Knowledge Check • 1. Compare the Heliocentric and Geocentric theories of the solar system. • 2. What is the difference between a terrestrial and gas planet? • 3. List the planets according to their distance from the sun. • 4. How do astronomers locate other planets outside our solar system?
Knowledge Check • 1. Compare the Heliocentric and Geocentric theories of the solar system. • Heliocentric – planets orbit the Sun • Geocentric – planets orbit the Earth • 2. What is the difference between a terrestrial and gas planet? • Terrestrial planet – small, rocky, inner solar system • Gas planet – large, gaseous, outer solar system • 3. List the planets according to their distance from the Sun. • Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto (though just taken off the list) • My Very Eager Mother Just Served Us Nine Pizzas • 4. How do astronomers locate other planets outside our solar system? • Can be detected by the effect of the planet’s gravity on the motion of the star it revolves around