distribution of matter in space
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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 . - PowerPoint PPT PresentationTRANSCRIPT
Section 1.3Pages 384-391
Distribution of Matter in Space
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
SupernovaAn 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 HolesA 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 GalaxiesSpiral – 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
Section 1.4Pages 392-400
Our Solar Neighbourhood
The SunThe 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 hypothesis1. 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: MercuryClosest planet to the
Sun
Surface similar to our moon
No atmosphere
High temperature – 400oC sunny side
- 180oC dark side
The Planets: VenusSimilar 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: EarthOnly 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: MarsRed 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: JupiterLargest 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: Saturn19 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: UranusUnusual 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 BodiesAsteroids – 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 BodiesMeteoroids – 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 LinksSolar System
Space Videos National Geographic
Section 1.5Pages 401-407
Describing the Position of
Objects in Space
AltitudeAltitude 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.
AzimuthAzimuth 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 SpaceThe 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 LearningPage 406
Questions 2-3, 5-7, 10- 11, 13-15, 17
Read Section 2 pages 408-433