INFORMATION. Chapter 7.1

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1 INFORMATION Chapter 7.1 Celestial is a term that refers to the sky Celestial Objects: objects we can see in the sky Astronomy: the study of the universe and the objects in it Astronomer: a person who studies astronomy When we observe super far objects, we are looking back in time because light takes time to travel The solar system: the sun with all the planets and other celestial objects that are held by the suns gravitational attraction Star: hot ball of plasma (an electrically charged gas) that shines because nuclear fusion takes place at its core Nuclear fusion is when the nuclei of atoms fuse together and form larger atoms. An astronomical unit was made to measure distances in space and is equal to avg distance between the sun and earth about 150 million km light year: distance light travels in a year- used to measure immense distances Asteroid belt: ring of rocky debris 3AU from the sun When a big star explodes, it creates a supernova due to the gradual buildup of heavy elements in the core causing the centre to collapse. outer layers are pulled into the core>temp and pressure increase>explosion A nebula is a large cloud of dust and gas and is the birthplace of stars. stars form when a lot of gas collects and gets drawn into a point and turns on when nuclear fission ignites it Chapter 7.2 Our galaxy is ly in diameter and 2000 ly thick Our Earth is tiny in comparison to the Milky Way galaxy All galaxies contain stars, planets, and dust Stars form from dust and gases present in nebulae Gravitational pull keeps celestial objects in place Black Hole: A region of space where gravity is so strong that nothing (including light) can escape Estimated that the Milky Way s Black Hole has been pulling stars for 7 billion years Black Hole has a mass equal to 3 million stars that are of similar size to our Sun

2 At least 90% of the Universe may be filled with matter that isn t even visible Dark Matter: Matter in the Universe that is invisible because it does not interact with light or any other kind of radiation Today, it is thought that most of the gravity in the Universe is produced by dark matter Galaxies contain groups of stars called Star Clusters Galaxies are classified in four main shapes: spiral, barred spiral, elliptical, and irregular Spirals are named after the way they look; spiral-shaped arms Elliptical look like flattened spheres Irregular do not fit into either category Galaxy Clusters are a bunch of galaxies grouped together It is believed by some astronomers that there are more than 100 billion galaxies QUESTIONS Chapter 7.1 What are three different celestial objects in our solar system? How do stars shine? In km, how long is an astronomical unit? Why are we looking into the past when we observe far away galaxies? What is a nebula? Chapter 7.2 What is the diameter and thickness of the Milky Way in light-years? What is a black hole? What makes up 90% of matter in our universe, according to astronomers? What are the four shapes of galaxies? Why do galaxies with more dust than others generally produce more new stars?

3 7.3 Evidence for The Big Bang By studying the light spectrum of many galaxies, Edwin Hubble, an astronomer, was able to find out how quickly galaxies were moving away, and how far away they were from the Milky Way. From his observations of the speed they were moving away and the distance from the Milky Way, Edwin Hubble discovered that the farther away a galaxy was, the faster it was moving away. These observations supported the idea that the universe is expanding and also the Big Bang Theory. The Big Bang Theory states that the universe was formed when an infinitely dense point suddenly and rapidly expanded. The expansion is what made all the matter and energy that exists today. The universe was formed 13.7 Billion years ago. The Big Bang Theory was mostly developed by physicist George Gamow and mathematician Ralph Alpher. Cosmic Microwave Background The Big Bang Theory stated that the early universe was very hot and was filled with short wave gamma ray radiation, and slowly the universe cooled and the wavelength of radiation lengthened. Scientists realized that if the theory was correct, then there should be radiation left over from the formation of the universe. In 1965, Arno Penzias and Robert Wilson developed a microwave antenna that was to be used in telecommunications. The microwave antenna detected that the entire sky was filled with microwave energy. This energy is called cosmic background radiation. In 1992, the Cosmic Background Explorer satellite created maps of the background radiation from distant parts of the universe. In 2006, the Wilkinson Microwave Anisotropy Probe made more detailed maps of the background radiation in the universe. The observations from both of these satellites support the Big Bang Theory. 1. What did Edwin Hubble discover by studying the light spectrum of different galaxies? 2. The Big Bang Theory states that the universe was when an infinitely point suddenly and rapidly. 3. How long ago was the universe formed? 4. Name two of the main contributors to the Big Bang Theory. 5. The Big Bang Theory stated that the was very hot and was filled with radiation, and slowly the universe and the wavelength of radiation. 6. How did scientists find out about cosmic background radiation?

4 7. What were the two devices that mapped background radiation in the universe? Chapter 8.1 Stars Stars are huge balls of hot gas or plasma. Nuclear reactions in the core convert matter into energy. Life Cycle of a Star Stars are born when a nebula (A cloud of dust and gas) collapses. When the nebula collapses, the region which has the greatest amount of matter will start to pull in everything else around it through gravity causing to spin. High pressures build up in the core causing it to glow. Formation Stages 1. At this stage, it is now known as a protostar. Eventually, the spinning protostar gets to millions of degrees Celcius. 2. Over tens of thousands of years, energy from the core eventually reaches the outside of the star. When the energy gets to outside, the now fully formed star begins to glow. Masses of Stars Low mass stars: These stars use less nuclear fuel than bigger stars. They burn fuel so slowly that they can last more the 100 billion years. Small red stars are called red dwarfs. Most of the stars in the universe are red dwarfs. Most red dwarfs die out and become white dwarfs. Medium mass stars: These stars burn through fuel faster than low mass stars, using it up in about 10 billion years. At the end of the period, the star begins to collapse on itself. But as it collapses, the star begins to build temperature and pressure inside the star, which starts the fusion of helium which then expands to become a red giant. The Sun is a medium mass star. High mass stars: High mass stars have 10 times the mass of the Sun. A high mass star is hotter, brighter and bluer than any other star. It uses all of its fuel in about 7 billion years, resulting in the same end of other stars. This time, the star fuses helium and becomes a supergiant. The End of Stars Supernovas When a star runs out of fuel or collapses again, it produces so much heat and energy that it explodes. This exploding star is called a supernova. The explosion blasts elements into space, where the different elements begin to fuse with its surroundings. The core of the star then turns into one of two outcomes: A Neutron Star or a Black Hole. If the star s mass was between 10 to 40 times the mass of the Sun then it will become a neutron star. A supernova explosion would be direct both outward and inward to the core. neutron stars are the densest objects known. If the star was more than 40 times the mass of the sun then it will become a black hole. After the supernova explosion, the star is put under so much gravitational pull that nothing can stop its collapse. The effect on gravity is so great that space, time, light and all other matter will fall into one single point and nothing can escape.

5 8.2 The Solar System The solar system is the sun and all the planets and other celestial object held together by the sun's gravitational pull. Our solar system is called the Milky Way. It was formed by the left over dust, gas, and other debris in the nebula that created the sun continued to spin creating other stars and small bodies that are now planets, asteroids, and other celestial objects. The milky way has 8 planets, four rocky planets (first 4: Mercury, Venus, Earth, and Mars) and four gaseous planets (last 4: Jupiter, Saturn, Uranus, Neptune). another important part of the milky way is the asteroid belt which is a large ring of celestial debris that are circling the sun in a ring shape. The Sun: The sun is the center of our galaxy and it is an example of a medium mass star. The sun as 6 layers, they are the: Core, Radiative Zone, Convective Zone, Photosphere, Chromosphere, and Corona. Other things occurring on our sun include Sunspots (Darker regions that are cooler than surrounding regions), Prominences (Large, bright stream of particles extending from the photosphere to the corona), and Solar Flares (A massive explosion that flings hot plasma into space). Match Definitions: a. Core b. Radiative Zone c. Convective Zone d. Photosphere e. Chromosphere f. Corona g. Asteroid Belt h. Solar System i. Gaseous Planets j. Pluto k. Rocky Planets 1. The outer layer of the sun, only visible during a solar eclipse. 2. Is really a planet but is discriminated by the scientific community (and calvin) 3. The first four planets,,, 4. This layer is considered the boundary between the outer and inner layers, it is the coolest part of the sun, and where the yellow colour originates 5. A region of rocks and other debris surrounding the sun 6. Is made of extremely dense plasma. Light is bounced around, absorbed, and reemitted here. It takes years for light to pass through this layer. 7. The giants are orbited by large numbers of moon 8. This layer appears red but is only visible during a solar eclipse. 9. The and all other celestial objects held together by it s gravitational pull. 10. Bubbly plasma oozes in this layer and circulates between hotter and cooler regions. 11. The place where Nuclear fusion occurs. Chapter 8.3

6 How the Earth, Sun and Moon interact to create events on Earth Day And Night: Day and night are caused by the Earth ROTATING. When it rotates so that you are not facing the sun, it is night time. When the Earth's rotation brings you around again to see the sun, or to face the sun, it is day time. Seasons: Seasons are caused by the TILT of the Earth. We are in the Northern Hemisphere. When it is tilted TOWARDS the sun, it gets warmer here and it is SUMMER. When the earth is on the other side of the sun, thus tilted AWAY, making it WINTER. Note From above the North pole, the Earth rotates counter clockwise. This is why the sun rises in the East and sets in the West. Phases of the moon: These are the phases of the moon as seen from the Earth. Each full lunar cycle takes 27.3 days. Waxing on (more moon) as wax goes onto the envelope, or skin. Waning off, as It s the other one! Eclipses An eclipse as defined by google is an obscuring of the light from one celestial body by the passage of another between it and the observer or between it and its source of illumination. Essentially, it is when one celestial object is blocked from us by another. Solar eclipses occur when the moon comes exactly between us and the sun. Lunar eclipses are more complicated. This is a SOLAR ECLIPSE, where the moon blocks our view of the sun

7 This is a LUNAR ECLIPSE, where the suns position makes it impossible to see the moon, as all the light is blocked by the Earth. Tides: Tides are caused by the moon s gravity pulling the Earth s water, and making bulges. Where this water is pulled, the water level rises, and the water levels on the other side of the Earth fall. Review Questions: 1. How long does it take for one Earth rotation? One revolution around the Sun? 2. Which phase of the moon starts the cycle? a. Waning Gibbous b. New Moon c. Full Moon d. Waxing crescent 3. Assume it is summer in the Northern hemisphere in position 1. By this logic, in what position will it be Spring in the Southern Hemisphere? 4. Define eclipse. Use specific examples to support your definition. 5. When looking up at the night sky, we see stars that appear to be moving. What causes this apparent motion?

8 Chapter 9 1. Draw a rough sketch of the Geocentric Model of the universe. 2. What was the other model called? a) The sunny side of the solar system b) The Heliocentric Model c) The Heliacentric Model d) The Suncentred Model 3. People at first believed in the Geocentric Model, but had to change it because they saw the planets seemingly moving backwards across the sky. What is this now known as? 4. What is a spinoff (in space technology)? a) A special kind of spaceship b) A product originally built for life on Earth, but adapted for life in outer space c) A product originally built for life in outer space, but adapted for life on Earth d) A device that allows you to have zero gravity 5. What makes the ISS (International Space Station) so cool? a) It s a neutral space for all countries (haha, space, get it?) b) I m cooler c) Outer space is pretty cold d) It s a research facility for outer space in outer space e) It is the largest spacecraft ever built f) A, D and E g) B and C 6. What was Canada s contribution to the ISS? a) Chris Hadfield b) The Canadarm and the Canadarm2 c) The Canada Arm and the Canada Arm 2 d) Another country living in it 7. What is Canada s contribution able to do? a) Move astronauts outside the space station, bend around corners, and grab objects b) Wave its hand

9 c) Sing with the Bare Naked Ladies d) Grab space junk and move astronauts 8. Name three spinoffs, go! 1) 2) 3) 9. Short answer: What are 3 health effects associated with microgravity (the zero gravity that occurs in space)? 10. a) Ground based telescopes are better for viewing outer space because we can zoom into certain planets to see them better. True False b) Why? 1) 2) 3) 11. Who invented the Hubble Telescope and what type of telescope is it? a) John Hubble, space based b) Maria Hubble, ground based c) Hubble Smith, ground based d) Edwin Hubble, space based 12. Why is space exploration good? a) Because there are space based technologies that we gain from b) Because we learn important information about the universe c) Because it helps us understand where we come from d) All of the above 13. What are some issues/questions that have arisen because of space exploration?

10 14. Canada was the country in the world to launch a satellite. a) Best b) 3 rd c) 8 th d) 5 th 15. GPS stands for: a) Geographically Poised System b) Geography s Perfect Senses c) Globally Paid for Stationary d) Global Positioning System