Distribution of Matter in Space

1. Distribution of Matter in Space Section 1.3 Pages 384-391

2. Stars • A star is a hot, glowing ball of gas (mainly hydrogen) that gives off light energy. • Very hot stars look blue, while cooler stars look red. • In the 1920's, EjnarHertzsprung and Henry Norris Russell compared the surface temperature of stars with its brightness (luminosity). • Stars fall into distinct groupings.

5. Birth of Stars

6. Birth of Stars

7. Life Cycle of a Star

8. Supernova • An enormous explosion that marks the death of a massive star. • Fusion has stopped and the star runs out of fuel. • Gravity causes the star to collapse upon its self. • The outer part of the star explodes with a shock wave.

9. Black Holes • A highly dense remnant of a star in which gravity is so strong that not even light from radiation going on inside the remnant can escape. • Event horizon – point at which light cannot escape. • Invisible to telescopes. • This shows how the path of a beam of light bends in the vicinity of a non-rotating black hole.

10. Star Groups • Constellations are the groupings of stars we see as patterns in the night sky. • There are 88 constellations and many are explained in Greek Mythology. • Asterisms are also groupings of stars but are not officially recognized as constellations.

11. Galaxies • A galaxy is a grouping of millions or billions of stars, gas and dust. • Held together by gravity. • The Milky Way Galaxy is the galaxy our solar system is a part of. • It is shaped like a flattened pinwheel, with arms spiralling out from the center.

12. Milky Way Galaxy

13. Types of Galaxies • Spiral – long curved arms radiating out from a bright central core – older to younger at the arms • Elliptical – football or egg – mostly old stars • Irregular – no notable shape – smaller size – mixture of young and old stars

14. Our Solar Neighbourhood Section 1.4 Pages 392-400

15. The Sun • The Sun emits charged particles in all directions. • This solar wind bombards the Earth at 400km/s, but the magnetic field of the Earth protects us.

16. Protoplanet hypothesis • 1. A cloud of gas & dust in space begin swirling • 2. Most of the matter (more than 90% of it) accumulates in the center - forming the Sun • 3. The remaining materials accumulate (forming planets) and circle the Sun

17. The Planets: Mercury • Closest planet to the Sun • Surface similar to our moon • No atmosphere • High temperature – 400oC sunny side • - 180oC dark side

18. The Planets: Venus • Similar in size, mass, and gravity to earth • High surface temperature – 450oC (melt lead) • 90 x atmospheric pressure to Earth • CO2cloud cover • Rotates opposite to other planets – east to west

19. The Planets: Earth • Only planet where water exists in solid, liquid, and gas • Only planet to support life • Atmosphere provides protection from the Sun • 70% surface covered in water • Active volcanism

20. The Planets: Mars • Red planet – orangish – caused by iron oxides on surface • Two polar ice caps (One of Co2 + H2O and one of CO2) • Extremely cold surface temperature • Varied surface topography • 2 moons

21. The Planets: Jupiter • Largest of all planets • Twice the mass of all other planets combined • Composed of mainly hydrogen and helium • Great Red Spot – atmospheric storm • Three thin rings • 28 moons

22. The Planets: Saturn • 19 moons • Second largest planet • 1000+ rings surround equator • Composed mostly of hydrogen and helium • High wind speeds over 1800 km/h due to fast rotation

23. The Planets: Uranus • Unusual axis of rotation – tilted toward the plane of its orbit –making it appear to roll its orbit • Composed mostly of hydrogen and helium • Methane in atmosphere gives it its blue colour • Large ring system • 17 moons

24. The Planets: Neptune • Composed mostly of hydrogen and helium, and methane • Methane in atmosphere gives it its blue colour • Little light reaches this planet • Fastest wind speed – 2500 km/h • Own ring system • 8 moons

25. The Planets: Pluto • Cold frozen ball of methane • Disqualified as a Planet due to its obit around the sun at 17.2o– more elliptical • Rotates east to west rather than west to east • Some astronomers believe it and Charon (moon) are comets that have been captured by the gravity of the sun • Originated from the Kuiper Belt

26. Other Celestial Bodies • Asteroids – rocky , metallic bodies ranging in size of a few meters to hundreds of kilometres • Comets – dirty snowballs – dust and ice and heat up when they come close to the sun, releasing gas • Comets have predictable paths – large ellipses

27. Other Celestial Bodies • Meteoroids – small pieces of rock flying through space with not particular path • Meteor – a meteoroid that gets pulled into the atmosphere by gravity – heats up and gives off light • Meteorite – a meteor that hits the surface

28. Hyper Links • Solar System • Space Videos National Geographic

29. Describing the Position of Objects in Space Section 1.5 Pages 401-407

30. Altitude • Altitude gives you the "how above the horizon it is” • The point straight overhead has an altitude of +90 degrees • Straight underneath, an altitude of -90 degrees. • Points on the horizon have 0 degree altitudes. • An object halfway up in the sky has an altitude of 45 degrees.

31. Azimuth • Azimuth determines "which compass direction it can be found in the sky." • An azimuth of zero degrees puts the object in the North. • An azimuth of 90 degrees puts the object in the East. • An azimuth of 180 degrees puts the object in the South, and one of 270 degrees puts the object in the west. • Zenith is the position in the sky directly overhead.

33. Motion of Objects in Space • The path in the sky along which the Sun takes is called the ecliptic. • The Celestial Sphere is the name given to the very large imaginary 'sphere of sky' surrounding the Earth.

34. Assess Your Learning • Page 406 • Questions 2-3, 5-7, 10- 11, 13-15, 17 • Read Section 2 pages 408-433