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Stoichiometry

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					        1.1
Early Views About
   the Cosmos
 A. Tracking the Cosmos
  ancient people looked to the skies to
   predict the coming of summer and
   winter
  summer solstice marks the longest
   day of the year… June 21 in the
  Northern Hemisphere

 winter solstice marks the shortest
  day of the year… Dec 21 in the
  Northern Hemisphere


Mrs. J. Agnew                      slide 1 of 7
many ancient structures were built to
 predict the timing of the solstices
    eg) Stonehenge




equinoxes are two times in the year
 when daylight and nighttime are
 equal in length (March 21 and
 September 21)
Mrs. J. Agnew                    slide 2 of 7
 B. Planetary Motion
objects in the sky are constantly moving

ancient peoples wished to make sense of it all




 models of planetary movement and star
 movement emerged

Mrs. J. Agnew                         slide 3 of 7
 constellations are patterns assigned
 to groups of stars in the night sky




  http://amazing-
  space.stsci.edu/tonights_sky/




Mrs. J. Agnew                     slide 4 of 7
 C. Geocentric Model
2000 years ago Aristotle proposed an
 Earth-centered (geocentric) model of
 the universe
  http://images.google.ca/imgres?imgurl=http://www.phys.unt.edu/Astronomy/online_course_files/sample_pages/header.jpg&imgrefu
  rl=http://www.phys.unt.edu/Astronomy/online_course_files/sample_pages/03_6_3.html&h=159&w=588&sz=38&tbnid=DX0wgZ_u
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 sun, moon, Mercury, Venus, Mars,
  Saturn and Jupiter orbit Earth

early astronomers used this model to
 calculate moon phases but couldn’t
 explain other celestial events


Mrs. J. Agnew                                                                                        slide 5 of 7
 D. Heliocentric Model
in 1530, Copernicus suggested a sun-
 centered (heliocentric) model of the
 universe

 Earth and the other
  planets orbit the
  sun

in the 1600’s, Galileo was the first
 scientist to use a telescope


Mrs. J. Agnew                       slide 6 of 7
 Brahe studied and recorded the
  movement of the planets

later, Kepler added elliptical (oval-
 shaped) orbits to the model




Mrs. J. Agnew                      slide 7 of 7
       1.2
Discovery Through
   Technology
 A. Astronomical Tools
  merkhets and quadrants were used by
  Egyptians to chart the stars
 Arabians used astrolabes and cross-
  staffs
 scientists like Galileo used telescopes,
  which contained combinations of
  different lenses
 telescopes are still used to observe objects in
  space


Mrs. J. Agnew                          slide 1 of 3
 B. Astronomical Units
units like metres and centimetres are
 too small for measuring distance in space

 astronomical unit (AU) is the distance
 from the center of the Earth to the
 center of the Sun
 1 AU = 149,599,000 km
AU’s are used to describe positions of objects
 in our solar system



Mrs. J. Agnew                         slide 2 of 3
 C. Light Years
in one second, light travels 300,000 km
sunlight takes 8.5 minutes to reach Earth

a light-year is the distance traveled
 by light in one year:
9,500,000,000,000 km = 9.5 trillion km


light-years are used to measure great
 distances between stars and galaxies


Mrs. J. Agnew                      slide 3 of 3
        1.3
The Distribution of
 Matter in Space
 A. Stars
 a star is a hot, glowing ball of gas
  (mainly hydrogen but also helium)
 stars vary in colour, size and density

  hot stars are blue , cool stars are red

 a Hertzsprung-Russell Diagram shows
  that stars fall into distinct groupings




Mrs. J. Agnew                        slide 1 of 6
           Hertzsprung-Russell Diagram




                                   Sun




Mrs. J. Agnew                            slide 2 of 6
 B. Star Birth
a nebula is an accumulation of gas
 and dust
steps in birth:
 1. swirling dust, gas collapse under
    gravity
 2. core mass and temperature increase
  3. core of material glows, forming a
     protostar
  4. when the core temperature reaches
     10 million degrees C, fusion begins
     and a star is born
Mrs. J. Agnew                     slide 3 of 6
 C. Life & Death of a Star
the mass of a star determines the type
 of star
most stars start out in the main sequence

the life cycle depends on the mass of
 the star




Mrs. J. Agnew                      slide 4 of 6
               sun-like           red giant   white dwarf    black dwarf
                stars




nebula       main sequence star
                                                            neutron star
                                                            (pulsar)
               massive           red          supernova
                stars         supergiant                    black hole




         Mrs. J. Agnew                                      slide 5 of 6
 D. Galaxies
a galaxy is a grouping of millions or
 billions of stars, gas and dust held
 together by gravity
can be spiral shaped (Milky Way),
 elliptical, or irregular




Mrs. J. Agnew                     slide 6 of 6
     1.4
  Our Solar
Neighbourhood
 A. Protoplanet Hypothesis
 model for explaining the birth of solar
  systems:
   1. cloud of gas and dust begins
      swirling
   2. >90% of material gathers in centre,
      forming sun
   3. remaining material clumps together
      into planets and moons



Mrs. J. Agnew                        slide 1 of 9
 B. The Sun
surface temperature = 5500C

core temperature =
 15,000,000C
 (15 million degrees)
 charged particles
 emitted by sun are called
 solar wind
Earth is protected from solar wind by its
 magnetic field


Mrs. J. Agnew                       slide 2 of 9
 C. The Planets
inner “terrestrial” planets are smaller
 and rockier
     Mercury             Venus




                Earth    Mars




Mrs. J. Agnew                    slide 3 of 9
outer “Jovian” planets are large and
 gaseous
     Jupiter            Saturn




           Uranus       Neptune




Mrs. J. Agnew                     slide 4 of 9
Pluto was the farthest
 planet until 2003




there is now a tenth
 planet with its own
 moon



Mrs. J. Agnew             slide 5 of 9
 D. Asteroids and Comets
asteroids are between a few metres and a
 few hundred metres in size
found in the asteroid
 belt between Mars
 and Jupiter




          Gaspra
Mrs. J. Agnew                    slide 6 of 9
comets are made of dust, rock and ice
 and move around the sun in elliptical
 paths
when comets come close to the sun, gases
 are released by the heat, forming very
 long tails (millions of km)

                                Halley’s
                                Comet


                                 Hale-Bopp
                                  Comet
  Shoemaker-Levy Comet
Mrs. J. Agnew                      slide 7 of 9
 E. Meteoroids, Meteors, Meteorites
meteoroids are pieces of rock floating
 through space
meteors are meteoroids that get
 pulled into the atmosphere…they
 glow brightly because of the heat of
 friction




Mrs. J. Agnew                    slide 8 of 9
meteorites are meteors that have hit
 the Earth’s surface




Mrs. J. Agnew                   slide 9 of 9
        1.5
  Describing the
Position of Objects
     in Space
 A. Positions of Objects
 to locate an object in space, two
  measurements need to be taken:

    1. azimuth – compass direction in
                 degrees from North
        eg) 0 = North, 180 = South
    2. altitude – how high up in the sky
       eg) 0 = horizon, 90 = straight up

 an altitude of 90 is called the zenith

Mrs. J. Agnew                          slide 1 of 4
                zenith




Mrs. J. Agnew            slide 2 of 4
 B. Motion of Objects
other stars appear to be motionless…they
 move only slightly over long periods of
 time
planets change positions in very short
 periods of time

the path the sun follows through the sky
 during the year is called the ecliptic




Mrs. J. Agnew                     slide 3 of 4
Mrs. J. Agnew   slide 4 of 4
       2.1
 Getting There:
Technologies for
Space Transport
 A. History
 ancient Greeks made rocket-
  propelled objects using steam
 in order to put an object into space, the
  pull of Earth’s gravity must be
  overcome

 Earth’s escape velocity is 40 000 km/h

 1957 – Russia launches Sputnik, the
  first artificial satellite


Mrs. J. Agnew                          slide 1 of 7
 B. Rocket Science
rockets are propelled using forces

for every action there is an equal and
 opposite reaction




Mrs. J. Agnew                         slide 2 of 7
rockets have three basic parts:
    1. structure and mechanical parts –
       rocket body, fins, engines etc
    2. fuel – liquid oxygen and hydrogen,
      gasoline (makes up most of the
      mass)
    3. payload –
      crew cabin, crew,
      air, water etc.



Mrs. J. Agnew                      slide 3 of 7
 C. Future Technology
 ion drives are engines that use
 electrically charged xenon gas

xenon is accelerated and emitted as
 exhaust, causing the rocket to move
 in the opposite direction

 weaker thrust than chemical fuel but
 lasts an extremely long time




Mrs. J. Agnew                       slide 4 of 7
there is no friction in space so the vehicle
 can go a long distance on very little fuel

 solar sails are thin sheets that will
  move when exposed to solar energy

the energy from photons from the sun is
 used to power the spacecraft and
 increase its speed
 carbon fibre is being used as a sail
 material


Mrs. J. Agnew                        slide 5 of 7
 D. Shuttles, Probes and Stations
 shuttles transport personnel and
 equipment to orbiting spacecraft

 probes contain instruments for
 exploring space robotically

 eg) Voyager space probe, Hubble
    Space Telescope




Mrs. J. Agnew                   slide 6 of 7
 space stations are orbiting spacecraft that
  allow people to live and work in
  space for extended periods of time




                  International Space Station
       http://www.nasa.gov/mission_pages/station/main/iss_top_10.html

Mrs. J. Agnew                                                  slide 7 of 7
       2.2
Surviving There:
Technologies for
 Living in Space
 A. Hazards
 there is no protection from the
  atmosphere in space
 outer space is called a “vacuum” which
  means there is no air, water or
  atmosphere

 astronauts may be exposed to cosmic
  and solar radiation




Mrs. J. Agnew                       slide 1 of 7
 exposed to meteoroids and extremes
  in temperature

  air and food have to be brought along

 stations and shuttles are small and
  cramped which can cause
  psychological problems




Mrs. J. Agnew                      slide 2 of 7
 B. Microgravity
 gravity is the force of attraction
 between masses
varies from planet to planet

 microgravity is the small amount of
 gravity acting on astronauts

 human bodies are used to the gravity
  on Earth



Mrs. J. Agnew                      slide 3 of 7
in orbit, astronauts experience
 “weightlessness” which can:
    1. weaken muscles
    2. reduce depth
       perception
    3. bones lose calcium
       and become brittle
    4.heart muscle weakens since it
       doesn’t have to pump as hard


Mrs. J. Agnew                      slide 4 of 7
 C. Space Suits
 space suits protect astronauts from
 hazards in space

space suits contain:
  1. layers of different
     materials
    2. air, water
    3. heating and cooling
       devices
    4.waste tubes

Mrs. J. Agnew                      slide 5 of 7
 D. Water
water may be filtered, purified and
 recycled many times during long
 space flights

International Space Station (ISS) will be
 recycling 100% of its water, including
 urine




Mrs. J. Agnew                         slide 6 of 7
 E. Air
oxygen is made by   the electrolysis of
 recycled water

 CO2, dust and microbes are removed
 from the air

temperature, air pressure and
 humidity are all controlled




Mrs. J. Agnew                      slide 7 of 7
       2.3
   Using Space
Technology to Meet
 Human Needs on
      Earth
 A. Communication
  wireless technology depends on
  communication satellites
   eg) cell phones, satellite TV,
      satellite radio



 satellites today use digital systems




Mrs. J. Agnew                       slide 1 of 4
 B. Research Satellites
 weather satellites are designed to stay
  in one position above the Earth
called geosynchronous orbit
 observation satellites, like LANDSAT
  and RADARSAT , are not in
  geosynchronous orbits
follow ships at sea, track
 forest fires, report on
 environmental change
 etc.

Mrs. J. Agnew                      slide 2 of 4
 C. Remote Sensing
 remote sensing satellites are in a low
 orbit (200 km – 1000 km altitude)

can take photographs of Earth’s surface or
 collect data from sensing heat and
 radiation




Mrs. J. Agnew                      slide 3 of 4
 D. Global Positioning
 24 global positioning satellites are in
 orbit around Earth
hand-held receiver picks up signal from 3 of
 the satellites and gives the precise location




Mrs. J. Agnew                        slide 4 of 4
        3.1
Using Technology
to See the Visible
 A. Optical Telescopes
 light is collected and focused into an
  image
  refracting telescopes use 2 lenses to
  form an image… maximum diameter of
  about 1 m




Mrs. J. Agnew                     slide 1 of 5
  reflecting telescopes use 1 lens and
  several mirrors to form an image...
  larger (6 m)




Mrs. J. Agnew                    slide 2 of 5
  segmented mirrors can be used to make
  one large telescope with enormous
  light-gathering ability and resolving
  power




Mrs. J. Agnew                    slide 3 of 5
 B. Combining Telescopes
 interferometry is a technique where 2 or
 more telescopes are used together to
 improve resolution
  eg) Keck I and Keck II at Mauna Kea
   Very Large Telescope (VLT) in Chile




Mrs. J. Agnew                     slide 4 of 5
 C. Hubble Space Telescope
 light and air pollution limits the
 resolution of telescopes on Earth
the Hubble Space Telescope is a
 reflecting telescope that orbits at an
 altitude of 600 km




Mrs. J. Agnew                      slide 5 of 5
        3.2
Using Technology
to See Beyond the
     Visible
 A. Electromagnetic Spectrum
  optical telescopes give us information
  based on visible light
 many objects in space emit radio waves,
  X-rays, infrared (heat) rays, gamma
  rays etc
  electromagnetic energy is energy that
  travels at the speed of light




Mrs. J. Agnew                       slide 1 of 7
 electromagnetic energy has different
  wavelengths and frequencies
 wavelength is the distance from one
  point on a wave to the same point on
  the next wave
 frequency is the number of waves
  passing a single point per second

 different forms of electromagnetic energy
  form the electromagnetic spectrum



Mrs. J. Agnew                        slide 2 of 7
Mrs. J. Agnew   slide 3 of 7
 B. Radio Telescopes
used to study radio waves emitted by
 objects in space

radio waves are not affected by weather,
 pollution or the atmosphere

can be used to study the distribution of
 matter in space




Mrs. J. Agnew                      slide 4 of 7
must be very large (300 m diameter)
 since radio waves have a long wavelength




Mrs. J. Agnew                     slide 5 of 7
 C. Radio Interferometry
combine multiple radio telescopes to get
 greater resolution

can be arranged in large
 groups called arrays
 to increase accuracy of
 measurements


can be used to see planets orbiting
 distant stars

Mrs. J. Agnew                     slide 6 of 7
 D. Space Probes
not all questions can be answered by Earth-
 based telescopes

 space probes are unmanned satellites
 and “landers” that put equipment on
 or close to other planets




Mrs. J. Agnew                        slide 7 of 7
        3.3
Using Technology
to Interpret Space
 A. Triangulation
  triangulation is based on the geometry
  of a triangle
 uses 2 angles and a baseline to
  determine the distance to an object




     baseline



Mrs. J. Agnew                     slide 1 of 6
 B. Parallax
 parallax is the apparent shift in
 position of an object (eg. star) when
 viewed from two different places
parallax is used to
 determine the
 angles for
 triangulation

the diameter of the Earth’s orbit is
 used as the baseline and the
 measurements are taken 6 months apart
Mrs. J. Agnew                    slide 2 of 6
 C. Star Composition
 prisms separate colours in visible light

 spectroscopes separate the light from
  stars into colours and bands called a
  spectrum

each element creates its own unique
 spectrum

the spectrum of a star is compared to the
 spectra of known elements to
 determine the star’s composition

Mrs. J. Agnew                       slide 3 of 6
          Absorption Spectrum of Hydrogen




Mrs. J. Agnew                               slide 4 of 6
 D. Star Motion
the Doppler effect is an apparent
 change in frequency of waves (sound,
 light) due to the movement of the
 source
changes in light waves can be used to
 determine how fast and in what
 direction a star or galaxy is moving




Mrs. J. Agnew                     slide 5 of 6
when a star is moving away from earth,
 the spectrum is red-shifted as
 wavelengths stretch out
when a star is moving towards the earth,
 the spectrum is blue-shifted as
 wavelengths compress




distant galaxies show a red-shift
 ….means universe is expanding
Mrs. J. Agnew                      slide 6 of 6
      4.1
  The Risks &
Dangers of Space
  Exploration
 A. Accidents
 1967 – fire broke out during
  training on Apollo 1, 3 died
 1986 – space shuttle Challenger
  exploded on lift off, 7 died




Mrs. J. Agnew                    slide 1 of 5
 2003 – space shuttle Columbia
  exploded on re-entry, 7 died




 both Russians and Americans lost, Mars
  probes losing huge amounts of
  money and years of work


Mrs. J. Agnew                     slide 2 of 5
 B. Dangers of Space Travel
risk of being hit by debris
risk of exposure to radiation in space
re-entry is very dangerous and must be
 perfect
       too shallow an angle and the shuttle
        bounces off the atmosphere
       too steep an angle and the shuttle
        burns up


Mrs. J. Agnew                          slide 3 of 5
 C. Space Junk
large and small debris can fall off
 spacecraft or be left behind
  eg) dead satellites, paint
junk and micrometeoroids might be
 small but are traveling at enormous
 speeds (20,000 km/h) and can have
 disastrous effects on a space shuttle or
 satellite




Mrs. J. Agnew                       slide 4 of 5
most space junk burns up if it re-enters
 Earth’s atmosphere

some old satellites can re-enter and the
 pieces fall to Earth posing a risk




Mrs. J. Agnew                       slide 5 of 5
       4.2
    Canadian
 Contributions to
Space Exploration
  & Observation
 A. Technology
 Canada developed and built robotic arms
  for the space shuttle
 called Canadarm 1 and Canadarm 2
 controlled by remote control




Mrs. J. Agnew                     slide 1 of 3
used to launch and retrieve satellites,
 fix the Hubble Space Telescope and
 put together modules of the
 International Space Station
Canadarm 2 has computer-controlled
 fingers
provided technology for the Mars
 Pathfinder mission




Mrs. J. Agnew                       slide 2 of 3
 B. Canadians in Space
Marc Garneau – 1st Canadian in space in
 1984
Roberta Bondar – 1st Canadian woman
 in space in 1992

Chris Hadfield – 1st Canadian to walk in
 space in 2001




Mrs. J. Agnew                      slide 3 of 3
        4.3
 Issues Related to
Space Exploration
 A. Should Space be Explored?
 con – there are lots of issues on Earth
  that haven’t been resolved
   eg) poverty, hunger, pollution,
   disease

 pro – space may offer some solutions
  to our problems




Mrs. J. Agnew                     slide 1 of 4
 B. Resources in Space
there is a great demand for natural
 resources on Earth
resources in space may help us satisfy our
 energy needs

asteroids contain mineral resources
       eg) Fe, Au, Pt




Mrs. J. Agnew                       slide 2 of 4
obtaining construction materials for space
 exploration from space would
 dramatically reduce the price

moon could provide materials for fuel

maybe could colonize other areas of the
 solar system, like Mars




Mrs. J. Agnew                        slide 3 of 4
 C. Issues
political issues refer to ownership,
 rights and laws
ethical issues refer to fairness, right vs
 wrong, determining the beneficial
 uses

environmental issues refer to
 protection and conservation of space
 and Earth



Mrs. J. Agnew                       slide 4 of 4

				
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