Distribution of Matter in Space Section 1.3 Pages 384-391

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, Ejnar Hertzsprung and Henry Norris Russell compared the surface temperature of stars with its brightness (luminosity). Stars fall into distinct groupings.

Birth of Stars

Birth of Stars

Life Cycle of a Star

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.

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.

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.

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.

Milky Way Galaxy

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

Our Solar Neighbourhood Section 1.4 Pages 392-400

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.

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

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

The Planets: Venus Similar in size, mass, and gravity to earth High surface temperature – 450oC (melt lead) 90 x atmospheric pressure to Earth CO2 cloud cover Rotates opposite to other planets – east to west

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

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

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

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

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

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

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

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

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

Hyper Links Solar System Space Videos National Geographic

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

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.

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.

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.

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