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STARS AND PLANETS Lesson 1 WHAT IS A NEBULA A nebula is the birthplace of a star. Consists of a large cloud of hydrogen and helium. TYPES OF NEBULAS Planetary Nebulas They have nothing to do with planets they just look like one in a small telescope. Form from a supernova explosion EMISSION NEBULA Emission nebulae are clouds of high temperature gas. The atoms in the cloud are energized by ultraviolet light from a nearby star and emit radiation as they fall back into lower energy states Often colored Red DARK NEBULA Dark nebulae are clouds of dust which are simply blocking the light from whatever is behind REFLECTION NEBULA Reflection nebulae are clouds of dust which are simply reflecting the light of a nearby star or stars. Often radiate blue LIFE CYCLE OF A STAR All stars originate in a nebula Nebulas pull hydrogen and helium using gravity and these elements condense to form a star. PROTOSTAR A protostar is a dense collection of gas. As gravity pulls in H and He it will begins to flatten and spin. CHECK FOR UNDERSTANDING What are nebulas? What is the chemical composition of a nebula? Why are nebulas significant to the universe? Complete answers with complete sentences and IN YOUR OWN WORDS!!! STAGE 1 When a nebula reaches about 100,000,000 years old it begins to form a protostar. When the protostar reaches 18,000,000 degrees F nuclear fusion of hydrogen begins to form helium. The larger the star, the shorter the star will live. OUR SUN A star like our sun began in a nebula. Friction and gravity pull elements together and a star is formed. Our star (the sun) is within the main sequence. STAGE 2: MAIN SEQUENCE A star spend 90% of its life within the main sequence During this stage nuclear fusion continues forming helium from the fusion of hydrogen. STAGE 3 When the star has spent nearly all of the hydrogen into helium the star enters the third stage. LEAVING STAGE 3 Depending upon the size of the star there are two options. 1. Turns into a Red Giant and then back to a nebula Or 2. Turns into a Red Supergiant and then explodes into a supernova. Red Giant The core of the star contracts because it is converting gravitational energy into thermal energy. This flood of energy pushes toward the surface and the outer shell of the star expands – the star now is referred to as a red giant. LEAVING THE MAIN SEQUENCE – 3RD STAGE RED GIANT COMPARISON STARS BALANCING ACT The outward pressures of the radiation from nuclear fusion resist the inward pull of gravity. When equilibrium is met, the star becomes stabile in size. STARS BALANCING ACT A star’s size is determined by its ability to balance heat and gravity. Gravity increases as the size of the star increases. The size of the star increases based on how much hydrogen it is fusing at its core. SUPERNOVA When the star reaches the fusion of Iron the stars gravitational force exceeds the outward force and the star collapses upon itself and explodes. CLOSEST STAR TO EARTH - ALPHA CENTAURI (4.24 LIGHTYEARS AWAY) ETA CARINAE IS A RARE “HYPER”GIANT A ONE OF A KIND STAR THAT IS SIMPLY TOO BIG. IT’S MASS - ABOUT 100 TIMES GREATER THAN OUR SUN AND AN EXCELLENT CANDIDATE FOR A SUPERNOVA. BETELGEUSE IS ABOUT 100,000 TIMES BRIGHTER THAN THE SUN AND 1,000 TIMES LARGER. BETELGEUSE WOULD EXTEND OUT TO THE ORBIT OF JUPITER ABOUT 1 MILLION YEARS LEFT OF NUCLEAR FUEL. Herschel Space Observatory 2013 CHECK FOR UNDERSTANDING Describe the birth of a star? How are stars and planets different? How are they similar? Why are stars significant to the universe? Complete answers with complete sentences and IN YOUR OWN WORDS!!! R Sculptoris (Red Giant) – using ALMA – Atacama radio telescope) Quickly heat continues to build up as the star tries to fuse carbon and oxygen. This results in cosmic burps – allowing the atmosphere to quietly eject its shell outward into a planetary nebula. LESSON 2 - FINAL STAGES OF A STAR (STAGE 4) The core then begins to contract due to gravity and is compressed into the size of our Earth. Creating a very dense and now a retired star. Lucy 2,500 mi diameter BPM37093 FINAL STAGES OF A STAR – STAGE 4 PLANETARY NEBULA – WHITE DWARFS Helix Nebula is a planetary nebula approximately 700 light-years away PLANETARY NEBULA – WHITE DWARFS Nebula Abell 39 - 7,000 lightyears distant toward the constellation Hercules PLANETARY NEBULA – WHITE DWARFS Planetary Nebula IC 1295 If the star is substantial in size (4x the mass of our sun) at the point of impasse, its gases will actually implode. Similar to a building being demolished. FINAL STAGES OF A STAR – STAGE 4 PLANETARY NEBULA - SUPERNOVA SN 1572 - Tycho's Resulting SN 1054 in a supernova and leaving behind a very dense Neutron star and a planetary nebula full of heavier elements like gold and silver. PLANETARY NEBULA – SUPERNOVA SN 1987a OUR SUN The sun is made up of a matter called plasma. Most abundant elements in the sun are (Horizons, 2012) Hydrogen – 91% Helium – 8.9% OUR SUN Our It star - is by far the largest object in the solar system contains more than 99.8% of the total mass of the Solar System (Jupiter contains most of the rest). The Sun does rotate, once every 25 days. Slower at the poles; as much as 36 days. This odd behavior is due to the fact that the Sun is not a solid body like the Earth. OUR SUN CHECK FOR UNDERSTANDING Why is our Sun important to our solar system? What is the composition of the Sun? Complete answers with complete sentences and IN YOUR OWN WORDS!!! HERTZSPRUNG - RUSSELL DIAGRAM The Hertzsprung-Russell Diagram is a graphical tool that astronomers use to classify stars according to their luminosity, spectral type, color, temperature and evolutionary stage. Most stars follow a sequence in their life in which the go from hot to cool and luminous to dull. SUN ANALOGY The Sun’s primary fuel source is hydrogen fusion. Referred to as nuclear fusion- it is the process by which nuclei combine to form a new, more massive nucleus creating energy in the process. All elements greater then Lithium (#3) have been formed by nuclear fusion in stars.* SUN AND NUCLEAR FUSION www.spacetechnology.com At the center of the sun the core makes up 25% of the sun’s total diameter of 864, 000 miles. The temperature of the core is about 28 million ºF. The surface is about 10,000 ºF THE CORE OF THE SUN The sun is a typical middle size star on the Hertzsprung diagram (G2V). The sun is in its prime it has spent 5 billion years on the main sequence of stellar life, it has 5 billion years to go before its rapidly decays. OUR SUN (STAR) ON A HERTZSPRUNG DIAGRAM Astronomers learn about stars by analyzing the light that the stars emit. Starlight passing through a spectrograph produces a display of colors and lines called a spectrum. ANALYZING STARLIGHT www.spacetechnology.com TEMPERATURE RANGE OF STARS Stars are categorized like our light spectrum - Blue being hottest, Red stars are coolest. A Blue star would have and average surface temp. of 63,000˚F, while a red star would have and average surface temp. of 5,400˚F Our Sun is a yellow star with average surface temp. of 10,000°F www.spacetechnology.com CHECK FOR UNDERSTANDING What is the Hertzsprung Russell Diagram? Draw the difference between Nuclear Fusion and Nuclear Fission? Complete answers with complete sentences and IN YOUR OWN WORDS!!! A galaxy is a collection of stars, dust, and gas bound together by gravity.* Galaxies are made of billions of stars and comprise most of the visible mass of the universe.* LESSON 3 – GALAXIES SPECTROSCOPY –WONDERS OF THE UNIVERSE DOPPLER EFFECT DOPPLER ON SHOW UNIVERSE’S AGE Detailed observations estimate the universe formed about 13.8 (Planck Collaboration, 2013) billion years ago. OLDEST SEEN GALAXY Galaxy named UDFy -38135539, spotted by the Hubble 2009 is oldest to date 13.1 billion years old (BYO). Hubble has found others, but scientists need better technology (Webb ’14) will feature infrared technology. HOW DO WE SEE OLD GALAXIES Very difficult – if lucky gravitational lensing can be used when a galaxy's image is being magnified by the gravity of a massive cluster of galaxies parked in front of it, making it appear 11 times brighter. A light year is a measure of distance, not time. It is the distance that light, which travels in a vacuum at the rate of 186,000 miles per second, can travel in a year. This is equal to 5,870 trillion miles. WHAT IS A LIGHT YEAR? www.spacetechnology.com CHECK FOR UNDERSTANDING What is a light year? What is Gravitational Lensing? Complete answers with complete sentences and IN YOUR OWN WORDS!!! Galaxies are classified by shape into three main types. 1. A spiral galaxy (like our own) has a nucleus of bright stars and flattened arms that spiral around the nucleus. About 77% of the observed galaxies in the universe are spiral galaxies. Grand Spiral Galaxy NGC 1232 THREE TYPES OF GALAXIES 1. SPIRAL (& BARRED) GALAXIES Elliptical Galaxy M87 Have a large range of sizes from over a million light-years in diameter to less than one-tenth the size of our own Milky Way. Very little gas and dust within and typically associated with being an older galaxy since most of their stars are old. 2. ELLIPTICAL GALAXIES They have no particular shape, and are fairly rich in dust and gas. 3. IRREGULAR GALAXIES www.spacetechnology.com 3. IRREGULAR GALAXIES Irregular galaxies are usually found in groups or clusters, where collisions and near-misses between galaxies are common. www.spacetechnology.com Types of galaxies according to the Hubble classification scheme. An E indicates a type of elliptical galaxy; an S is a spiral; and SB is a barred-spiral galaxy. HUBBLE GALAXIES www.spacetechnology.com We are Located in the Milky Way, has a diameter of about 100,000 light-years and may contain more than 200 billion stars. OUR MILKY WAY www.spacetechnology.com It a spiral galaxy in which the sun is one of hundreds of billions of stars and rotates 510,000 mph making one complete circuit every 230 million years. OUR MILKY WAY DOPPLER EFFECT The spectrum of a galaxy that is moving toward or away from Earth appears to shift, due to the Doppler effect. Doppler effect is an observed change in the frequency of a wave when the source or observer is moving. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an observer. CHECK FOR UNDERSTANDING Provide an example of a Doppler Effect and be prepared to explain your example to the class. Name and describe the 3 types of Galaxies and draw each type. Complete answers with complete sentences and IN YOUR OWN WORDS!!! BLUE SHIFT & RED SHIFT OF A STAR GEORGIA EDU. Galaxies moving toward Earth are shifted slightly toward blue, which is called blue shift. Galaxies moving away from Earth are shifted slightly toward red, which is called red shift. Cosmologists and astronomers can use the light given off by an entire galaxy to create the spectrum for that galaxy. GALAXY SPECTRUM (1889-1953) American astronomer confirmed the existence of galaxies other than the Milky Way. Using the largest telescope on Earth (Mt. Wilson) he deduced that the farther away the galaxy, the faster it was moving away from us. This relation, known as Hubble’s Law, was observational proof that the universe was expanding. EDWIN HUBBLE THE EXPANDING UNIVERSE Using Hubble’s observations and the latest technologies, astronomers have been able to confirm that the universe is expanding. THE BIG BANG The most accepted theory to date that explains why we are expanding is known as the Big bang theory. It explains that all matter and energy in the universe was compressed into an extremely small volume that 13.8 billion years ago exploded and began expanding in all directions. CHECK FOR UNDERSTANDING What are the Red Shifts and Blue Shifts and how do scientist use these to explore and understand our universe? How do astronomers know the universe is expanding. Complete answers with complete sentences and IN YOUR OWN WORDS!!! LESSON 4 FORMATION OF OUR SOLAR SYSTEM Our It solar system is 4.6 billion years old. was created by fragments of an interstellar gas clouds (solar nebula). FORMATION OF PLANETS This cloud would have been mostly hydrogen with some helium and small amounts of the heavier elements – which is what you see in the composition of the Sun. The solar nebular theory (SNT) supposes that planets form in the rotating disks of gas and dust around our young star. Proof- the sun, planets and moons mostly revolve and rotate in the same direction. The planet orbits, for the most part, lie close to a common plane. SOLAR NEBULAR THEORY SOLAR NEBULAR THEORY When the sun became hot enough, the remaining gas and dust were blown away into space, leaving the planets orbiting the sun. CLEARING THE NEBULA Occurs because of the sun’s radiation pressure and strong surging wind from the young sun. Planets would help clear the nebula by sweeping up the remaining space debris. ORIGIN OF THE SOLAR SYSTEM The major factor in the origin of the solar system is temperature. ORIGIN OF THE SOLAR SYSTEM The inner nebula was hot, and only metals and rock could condense there. The cold outer nebula could form from lots of ices along with metals and rocks. ORIGIN OF THE SOLAR SYSTEM The ice “frost” line seems to have between Mars and Jupiter, and it separates the region for formation of the high-density Terrestrial planets from that of the low-density Jovian planets. DENSITY DIFFERENCES OF THE PLANETS The variation in densities is an important clue to understanding the making of the solar system. The four inner planets are small with high densities while the four outer planets are large and have low densities. INNER PLANETS The heavier density is due to larger percentages of heavy elements, such as iron, magnesium and aluminum. The inner Terrestrial planets are Mercury, Venus, Earth, and Mars. OUTER PLANETS The outer planets are rich in low density gases like hydrogen and helium. They four outer Jovian (Gas Giants) are Jupiter, Saturn, Uranus, and Neptune. ORIGIN OF THE SOLAR SYSTEM Technically It Saturn is so light… can float on water. PLUTO Declassified in 2006 as a planet to dwarf planet, asteroid number 134340. In order to be a planet there are 3 rules. (1) Must orbit a Star (2) Have sufficient mass so that it is round in shape (3) has cleared the neighborhood around its orbit. PLUTO KUIPER BELT Use picture to show a clear neighborhood Kuiper belt a region of the solar system that is just beyond the orbit of Neptune and that contains small bodies made mostly of ice. Including dwarf planets of Eris and Pluto. Asteroids are understood to be the last remains of the rocky planetesimals that formed in the warmer inner solar system and therefore could not incorporate much ice. Most are between Mars and Jupiter – including Ceres (another Dwarf planet). ASTEROIDS COMETS Comets are quite small and composed of a fluffy mixture of ice, dust and significant amounts of empty space. They easily break apart when they pass by the Sun and are believed to have formed in the cold outer solar system, the huge comet cloud known as the Oort Cloud. www.spacetechnology.com OORT CLOUD The Oort Cloud is considered the edge of the Sun's orb of physical and gravitational influence and answers the question where do comets come from? OORT CLOUD When Earth first formed, it was very hot but over time cooled to form three distinct layers. In a process called differentiation, denser materials sank to the center, and less dense materials were forced to the outer layers. LESSON 5 – EARLY SOLID EARTH RESONANCE WINE GLASS MYTH BUSTER BRIDGE The center is a dense core composed mostly of iron and nickel. Around the core is a very thick layer of iron- and magnesium-rich rock called the mantle. The outermost layer of Earth is a thin crust of less dense, silica-rich rock. EARLY SOLID EARTH Eventually, Earth’s surface cooled enough for solid rock to form from less dense elements that were pushed toward the surface during differentiation. PRESENT DAY EARTH The Earth formed 4.6 billion years ago (BYA), at this point, it was nothing more than a molten ball of rock surrounded by an atmosphere of hydrogen and helium. EARTH’S EARLY ATMOSPHERE EARTH’S EARLY ATMOSPHERE In the beginning the Earth did not have a magnetic field to protect it. The intense solar wind along with the collision with the moon blew this early 1st atmosphere away. 2nd atmosphere formed through outgassing of active volcanoes as Earth cooled to form a solid crust (4.4 BYA). These volcanoes spewed out gasses, like water vapor, carbon dioxide and ammonia. OUTGASSING Light from the Sun broke down the ammonia molecules released by volcanoes, releasing nitrogen into the atmosphere. Over billions of years, the quantity of nitrogen built up to the levels we see today. ORIGIN OF NITROGEN Although life formed just a few hundred million years later, it was not until the evolution of bacteria 3.5 billion years ago that really changed the early Earth atmosphere into the one we know today. ORIGIN OF OXYGEN Fossils of early bacteria at least 3.4 BYA (HORIZONS 2012) known as cyanobacteria (stromatolites)– would have used energy from the Sun for photosynthesis, and release oxygen as a byproduct. They also sequestered carbon dioxide in organic molecules. ORIGIN OF OXYGEN Over hundreds of millions of years, this bacteria would completely change the Earth’s atmosphere composition, bringing us to our current mixture of 21% oxygen and 78% nitrogen. ORIGIN OF OXYGEN The abundance of oxygen (O2) would also create a special oxygen molecule known as ozone (O3) in the stratosphere. Most ecosystems rely on the ozone to protect them from harmful ultraviolet (UV) light from the Sun. OZONE IN EARTH’S PRESENT ATMOSPHERE Scientists believe Earth’s water was delivered sometime after the planet formed. Close proximity to the sun would have boiled off water inside rocks that were part of the original building materials (assuming that is where we started). FORMATION OF EARTH OCEANS FORMATIO N OF EARTH OCEANS So far water (ice) found on most comets does not match water on Earth. (deuterium (2H) = heavy hydrogen D2O) Some think asteroids were the primary source of water HOW EARTH RECEIVED WATER – THE LATE HEAVY BOMBARDMENT One theory that would explain the existence of foreign water is known as the Nice Model. HOW EARTH RECEIVED WATER – THE LATE HEAVY BOMBARDM ENT The Nice Model postulates that the planets formed in a much more compact configuration and that the planets started crossing one another due to the 2:1 synchronous resonance of Jupiter and Saturn 3.9 BYA. This resonance would scatter Uranus and Neptune into their current orbits around the Sun and also disrupted the ice particles of the Kuiper Belt creating the “Late Heavy Bombardment” or cosmic pinball machine. HOW EARTH RECEIVED WATER Hal Levison is a planetary scientist (Colorado) and worked on the Nice Model. While asteroids remain a prime suspect scientist have found some proof from Kuiper Belt Comet Hartley 2, that comets can have the same water chemistry that matches Earth (Klotz 2011). HOW EARTH RECEIVES WATER Most scientists agree on the Giant Impact Hypothesis which states that the formation of the moon began when a large object (Thea) collided with Earth around 4.5 bya. This hypothesis would explain why moon rocks share many of the same chemical characteristics of Earth’s mantle. LESSON 6 - THE CREATION OF OUR MOON Rocks from the lunar terrae, “lands” are lightcolored, coarse-grained and contain calcium and aluminum. Rocks from the maria, “seas” are dark-colored fine-grained basalts and contain titanium, magnesium, and iron. THE LUNAR ANATOMY Craters abound on the moon, at least 30,000 of them boasting a diameter greater then 0.6 miles. Most of the craters that cover the moon formed when debris struck the moon between 3.9 and 3.8 billion years ago (BYA). THE MOONS SURFACE THE LUNAR ANATOMY The dark and light patches on the full moon’s surface reveal the bright mountains, dark plains, and thousands of giant craters that tell of a long history of violent impacts. Aristotle (322 B.C.) suggested an Earthcentered, or geocentric, model of the solar system. In this model, the sun, the stars, and the planets revolved around Earth. GEOCENTRIC MODEL OF THE SOLAR SYSTEM The major problem with a geocentric model is that it does not explain the retrograde motion of the planets in our night sky. EPICYCLES MODELS OF THE SOLAR SYSTEM Ptolemy (168 A.D.) theorized that planets most move in small circles, called epicycles, as they revolved in larger circles around Earth. EPICYCLES MODELS OF THE SOLAR SYSTEM This model made some sense and the astronomical predictions of Ptolemy's geocentric model were used to prepare astrological charts for over 1500 years. EPICYCLES MODELS OF THE SOLAR SYSTEM CHECK FOR UNDERSTANDING What is the Geocentric Model of the solar system and who created it? What does epicycles refer to? What is the anatomy of the moon? In 1543, the geocentric system met its first serious challenge with the publication of Copernicus’ ‘De revolutionibus orbium coelestium’, which suggested that the Earth and the other planets instead revolved around the Sun. Aristarchos (230 BC), was a Greek mathematician, presented the first known heliocentric model of the solar system. HELIOCENTRIC MODELS OF THE SOLAR SYSTEM HELIOCENTRIC MODELS OF THE SOLAR SYSTEM Despite Copernicus’s convincing work, the geocentric model does not go away quickly. With the Invention of the telescope 1609, Galileo made observations of Jupiter’s moons which also called into question some of the tenets of geocentrism but his work alone did not seriously threaten it. HELIOCENTRI C- TURNING THE TIDE Kepler As the telescope becomes more accessible and refined (better) Galileo’s work along with: Kepler, Brahe, Cassini and Huygens were finally enough to turn the tide of the skeptics. Sir Isaac Newton would be born the same day Galileo died. In the 1700’s Newton’s laws of motion, when combined with his law of gravity and Kepler’s elliptical orbit theory, successfully explained all motions of astronomical bodies for the next 200 years. HELIOCENTRICTURNING THE TIDE In 1758 the Catholic Church dropped the general prohibition of books advocating heliocentrism from the Index of Forbidden Books. In 1822 Pope Pius VII approved a decree by the Sacred Congregation of the Inquisition to allow the printing of heliocentric books in Rome. OPPOSITION TO HELIOCENTRISM WANES CHECK FOR UNDERSTANDING What is the Heliocentric Model of the solar system and who created it? What significant findings did Newton and Kepler discover? LAND TELESCOPES Telescopes The Chile’s Atacama Desert have come a long way since Galileo. European Southern Observatory is planning to build a telescope in Chile that will be almost half the length of a soccer field in diameter and gather 15 times more light than the largest optical telescopes operating today. LAND TELESCOPES Here in L.A we have the Griffith Observatory which allows the entrance to the general public for a fee – of course. While land telescopes are more accessible, space telescopes have the advantage of no atmospheric interference (weather, dust, smog). HUBBLE SPACE TELESCOPE The Hubble Space Telescope was developed NASA and deployed from shuttle Discovery, STS-31 April 25, 1990. Hubble’s domain extends from the ultraviolet, through the visible (to which our eyes are sensitive), and to the nearinfrared. HUBBLE DEEP FIELD www.spacetechnology.com Developed by Cal Tech in Pasadena and operated by JPL, the NASA Spitzer Space Telescope is designed to detect infrared images. It was launched by Delta II rocket Aug. 25, 2003. SPITZER SPACE TELESCOPE SPITZER MESSIER 95 CHANDRA SPACE TELESCOPE Launched NASA's July 23, 2003 STS 93–Shuttle Columbia Chandra X-ray Observatory is designed to detect X-ray emission from very hot regions of the universe such as exploded stars, clusters of galaxies, and matter around black holes. CHAND RA M84 PAST, PRESENT AND FUTURE OF SPACE TELESCOPES JAMES WEBB SPACE TELESCOPE (JWST) The James Webb Space Telescope is an orbiting infrared observatory that will complement and extend the discoveries of the Hubble Space Telescope, with longer wavelength coverage and greatly improved sensitivity. WHERE WILL THE JWST ORBIT