12. TrackingCosmologicalEvents
Solstice:
• The word comes from Latin - Sol=sun stice=stop
• Longest and shortest days of sunlight during the year.
In the Northern hemisphere the summer solstice happens around June 21 and is
the longest period of daylight. This marks the first day of summer. The winter
solstice happens around December 21 and is the shortest period of daylight. This
marks the first day of winter.
Equinox:
• The word comes from Latin - Equi=equal nox=night
• 2 Days of the year where there is equal daylight and night during the year.
In the Northern hemisphere the spring equinox happens around March 21 and the
fall equinox happens around September 21
14. NewgrangePassageTomb
The oldest site that has definite astronomical
connections is Newgrange Passage Tomb in Ireland
that dates from about 3,200 B.C.
For about 2 weeks on either side of the winter solstice,
light passes through a roof box above the
entrance passage. This incoming light causes the
entire central passageway to be illuminated. Many of the
stones that make up Newgrange are decorated with
symbols that look like the sun.
15. Stonehenge
The most famous English site for
Neolithic astronomical use
is Stonehenge. The main stones of the
site date from about 3,000 B.C.
Some people believe that the
clear alignments of the stones with the
sun and the moon allowed the Druids
who built it to predict solar and
lunar eclipses. However, most people
believe that the site had some
religious importance attached to it rather
than an astronomically predictive value.
16. MedicineWheel
The Medicine Wheel’s large
circle measures 213
feet around. The 28 spokes
radiating from its center
represent the number of days in
the lunar cycle. Six
spokes extending well beyond
the Wheel are aligned to
the horizon positions of sunrises
and sunsets on the first days of
the four seasons.
17. AncientViews
Ancient monuments had a view that put the Earth at rest in the center of the
Universe.
The Egyptians saw the sky as the arched body of the goddess Nut
The Hindus saw the sky resting on the tusks of an immense elephant
The Babylonians saw the sky as the inside of a huge bell jar
The Arabs more recently saw the sky as an immense tent.
There were many views of the Earth’s position, however very few of these
descriptions suggested that the Earth actually turned.
18. GeocentricModel
Geocentric Model: proposed by Aristotle
that Earth is at the center, surrounded by the
Sun, the Moon and the five planets known at
the time. It also had stars that were fixed to
the outermost sphere.
The geocentric model allowed early
astronomers to forecast such events as the
phases of the Moon, but it still could not
explain many other observations. For
example, why did Mars, Jupiter, and Saturn
sometimes seem to loop back opposite to
their usual movement across the sky?
19. HeliocentricModel
Heliocentric Model: proposed by
Nicholas Copernicus and had the Sun at the center,
surrounded by Earth and the other planets. It also
had stars that were fixed to the outermost sphere.
A little less than 100 years later, a new generation of
scientists—with the help of a major technological
invention, the telescope—provided solid evidence
for Copernicus’s theory. Notable among these
scientists was the renowned Galileo Galilei of Italy.
Even though Galileo’s discoveries added credibility
to the Copernican ideas, the model could still not
predict planetary motion very accurately.
20. Ellipses
A German mathematician, Johannes Kepler, came up with the next solution to the
puzzle. Using detailed observations of the movement of the planets (observations
carefully recorded by the great Danish astronomer, Tycho Brahe), Kepler discovered
what was missing from the Copernican ideas. The orbits of the planets, he realized,
were ellipses and not circles.
Ellipse: The shape in
which planets orbit.
Similar to an oval shape
22. Sundial
Sundial: The sundial has been used
for more than 7000 years to
measure the passage of time.
The merkhet uses a string with a weight
on the end to accurately measure a
straight vertical line, much like a plumb
bob. A pair of merkhets were used to
establish a north-south line by lining them
up with the pole star. This allowed for the
measurement of night-time hours as it
measured when certain stars crossed a
marked meridian on the sundial.
27. AstronomicalUnits
Astronomical Units (AU): is used to measure distances inside our solar
system.
1 AU = the average distance from the center of the Earth to the center
of the Sun (149 599 000 km)
28. Light-year
Light-year: is the distance that light travels in
one year
Light travels at 300 000 km/s So 1light-year =
9.5 trillion km
Interesting fact: The light from stars can
take many thousands of years to reach us, so
some of the stars that we see at night may no
longer exist.
31. WhatisaStar?
Star: A star is a hot, glowing ball of gas (mainly hydrogen) that gives off
tremendous light energy.
Very hot stars look blue and cooler stars look red.
32. Hertzsprung-RussellDiagram
In the 1920’s Ejnar Hertzsprung and
Henry Norris Russell developed this
diagram by graphing data
from thousands of stars.
Hertzsprung-Russell Diagram: a
graph developed to organize and
group stars based on their
brightness and temperature
35. TheBirthofaStar
Nebula: Stars form when dust
and gas roll around creating
a nebula.
Nebular are made of about
75% hydrogen and 23% helium,
the other 2% is oxygen,
nitrogen, carbon, and
silicate dust.
36. TheBirthofaStar
Gravity acting between the gas and dust can create a rotating cloud
As more material is drawn into the spinning ball the mass of its
core and its temperature increases
When the temperature is hot enough it will start to glow – this is
called a protostar, and is the first stage in a stars formation
41. GroupsofStars
Constellations: are groupings of stars that form patterns.
There are 88 constellations recognized by the AstronomicalUnion.
Asterisms: Unofficial constellations such as the Big Dipper are
called asterisms.
Galaxy: A grouping of millions or billions of stars, gas, and dust held
together by gravity is called a galaxy.
44. ProtoplanetHypothesis
Protoplanet hypothesis - is a model used to explain the birth of solar
systems.
There are 3 steps:
1) a cloud of dust and gas begins swirling
2) most of the material (more than 90%) accumulates in the center,
forming the Sun
3) the remaining material forms smaller clumps circling the center.
These are the planets.
46. TheSun
Some Information:
is almost 110 times wider than
Earth
if it were hollow could fit almost
1 million Earth's inside
surface is 5500 °C
core is ~ 15 000 000 °C
47. TheSun
The sun gives off charged particles
called 'solar wind', that flow
very quickly in every direction.
the solar wind passes Earth at ~
400 km/s.
Earth is protected from the solar
wind by its magnetic field.
50. ThePlanets
The Planets
Inner or Terrestrial
(Also called Earth-like)
Outer or Jovian
(In reference to Jupiter)
Smaller, Rockier,
Closer to the Sun
Larger, Gaseous,
Farther from the Sun
Ex: Mercury, Venus,
Earth, Mars
Ex: Jupiter, Saturn,
Uranus, Neptune
Add flow chart to your notes
51. OtherBodiesintheSolarSystem
Asteroids: rocky or metallic bodies travelling in space with predictable
orbits.
Comets: often described as "dirty snowballs," are made up of dust and ice
Ex. Halley's comet is visible every 76 years. Last seen 1986 - next time 2062.
53. OtherBodiesintheSolarSystem
When a comet gets close to the sun it will begin to glow
and a tail will form. This is because the Sun heats up the
materials in the comet and gases are released. The gases
are pushed away by the solar wind creating the
appearance of a tail. The tails of some comets can
be millions of kilometers long.
Comets usually travel slowly orbiting the outer reaches of
the solar system. A close passing body can change the
comets course and it can end up orbiting the Sun. Comets
orbit the Sun in an elliptical path so they will make a
predictable appearance.
54. OtherBodiesintheSolarSystem
Meteoroids: small pieces of rock flying through space
with no particular path
Meteoroids are:
as small as a grain of sand, as big as a car
falling star is just a meteoroid that heats up as it
enters the Earth’s atmosphere
if it lasts long enough to hit the Earth it's called a
Meteorite
58. Position of Objects in Space
You have just discovered what you think might be a new star and you
would like a friend next door to check it out on their telescope.
How can you be sure you are both looking at the same thing?
59. Position of Objects in Space
We use 3 different measurements:
Azimuth: is the compass direction where due north is 0° and is read by
going clockwise.
Altitude: measures how high in the sky an object is; the horizon line is 0°
and straight up is 90°.
Zenith: is the highest point directly overhead.
65. Technology for Space Transport
1. What do we have to overcome to be able to get an object into space?
What speed is necessary to do this?
The force of gravity pulling the object back toward Earth.
The speed necessary to do this is 28 000km/h.
2. What was the first rocket ever recorded?
Archytas's "pigeon" is said to be the first rocket ever recorded.
66. Technology for Space Transport
3. Describe the details surrounding the launching of the first
artificial satellite.
On October 4, 1957, the Soviet Union launched Sputnik I into orbit. It was
about the same size as a large basketball.
4. What was the significance of the second satellite that the Soviet Union
launched?
It was the first time any living creature had been sent into space. The
information gained from the mission set the path for human space travel.
67. Technology for Space Transport
5. What is the fundamental law
of physics that rocketry relies on?
For every action, there is an equal
and opposite reaction.
6. Sketch how this law of physics
applies to how a rocket
is propelled. (Refer to figure 2.7)
68. Technology for Space Transport
7. There are three basic
parts to a rocket. List
what these are in the
chart below along with a
description and a
breakdown in
percentages of how much
of the total mass it makes
up.
69. Technology for Space Transport
8. Diagram and label the
cross section of a rocket
(Figure 2.8)
70. Technology for Space Transport
9. Describe and sketch in the space below the two alternatives to rocket
engines that scientists are studying, especially for propelling spacecraft on
long journeys.
Ion Drive: use xenon gas instead of chemical fuels. The xenon is
electrically charged, accelerated, and then emitted as exhaust. This
action pushes the spacecraft in the direction opposite to the emission
71. Technology for Space Transport
9. Describe and sketch in the space below the two alternatives to rocket
engines that scientists are studying, especially for propelling spacecraft on
long journeys.
Solar Drive/Sails: the photons hit the sail; the energy transmitted causes
the spacecraft to move
72. Technology for Space Transport
10. Name and provide a description of the three main types of spacecraft in
use.
Shuttles transport people and equipment to orbiting spacecraft.
Space probes contain instrumentation for carrying out robotic exploration of
space.
Space stations are orbiting spacecraft that have living quarters, work areas,
and all the support systems for living and working in space for long periods of
time.
73. Technology for Space Transport
11. What is the International Space Station and what purpose will it serve?
It is a space station built by the partnered effort of 16 nations (Canada,
United States, Japan, Russia, Brazil, and ll European nations.
It will serve as a permanent laboratory in space, as well as a command post
for building and launching interplanetary rockets.
76. Satellites
Satellites (artificial satellites): are objects that are built and sent to Earth's
orbit. They have electronic equipment to transmit information they receive to
ground stations by radio waves.
77. Communication Satellites
In the early 20th century, in order to talk to other people, telephone lines
were used. This got to be expensive!
Now wireless communication is used by digital systems employed by
satellites.
78. Satellites for Observation and Research
Weather Satellites: Weather satellites are placed above the same location.
Their rotation is called a geosynchronous orbit because it rotates in-sync with
the Earth. This enables them to focus on one area giving a 24-hour a day
monitoring of weather.
Geosynchronous Orbit: rotates
in-sync with the Earth
79. Satellites for Observation and Research
Satellites not in geosynchronous orbit follow ships at sea, track forest fires,
search for natural resources, etc. Some examples are LANDSAT and RADARSAT.
80. Remote Sensing
Low Earth-orbit satellites are used for remote sensing. These take images of the
Earth's surface to send back to Earth.
This can send information like: heat, invisible energy waves, natural resources,
and effects of urbanization.
81. Personal Tracking Satellites
GPS (Global Positioning Systems): are used to track where a person is at a given
time. Radio signals are transmitted to a hand-held receiver. They are accurate
to within a few metres.
84. Optical Telescopes
First one built in 1608 by Hans Lippershey,
but Galileo was the first to use a telescope
to see the sky.
Optical telescopes: gather and focus light
from stars so we can see.
The larger the lenses or mirrors, the further
we see.
87. Reflecting Telescopes
How do you make a mirror big enough?
Spin-casting uses molten glass poured into
a spinning mould. After it solidifies, it is
grinded to a specific shape.
Mirrors can also be segmented. This is
many parts of a mirror
88. Interferometry
Interferometry: combining two or more
telescopes together.
This helps improve the resolution of
images.
example: Mauna Kea, Keck I, and Keck II,
over 85m apart but produce clearer
images than the best Earth- based
observatory.
89. Hubble Space Telescope
Hubble Space Telescope
Orbits about 600km above Earth and uses a
series of mirrors to focus light from far
objects.
Built in 1990, it is cylinder- shaped and
measures 13m by 4.3m. Its simple design
makes repairs easy.
Hubble orbits the Earth in about 95 minutes!!
90. Advantages & Disadvantages of Visible Telescopes
Advantages:
sees what we see (colour intensity of
light)
can be made using simple materials
Disadvantages:
cannot see during the day time
can be affected by clouds and weather
92. Electromagnetic Spectrum
Electromagnetic energy: are forms of radiated energy
that travel the speed of light, they will have different
wavelengths and frequencies than light.
Frequency: is the number of waves that pass a
single point in one second.
Gamma rays have high frequency and a very
short wavelength.
Radio waves have low frequency and a very
long wavelength.
94. Other Spectrum Telescopes
Infrared telescopes: can see through
nebular dust and can observe star
formation. These are not as affected by
the atmosphere.
Radio telescopes: unaffected by
weather, pollution or atmosphere. Can
discover much about the composition
and Can see through nebular gas.
96. Triangulation
Triangulation: Using measurements and
scale drawings of triangles to find the
distance to a far object.
Why is this helpful?
For distances far away you can measure
them without going to the object.
Example: measuring the distance across a
river (but you don't have to cross the
river).
97. Triangulation
Steps:
1. On a flat area, measure off a baseline and mark off each end.
2. Select an object you can see on the opposite side of the river.
3. At one end of the baseline, use a protractor to determine the angle of the
end of the baseline and the object you are looking at.
4. Stand on the other end of the baseline and repeat.
5. Make a scale drawing of the triangle with the baseline and angles.
6. On the drawing, make a perpendicular line from the baseline to the tip
(or to the object you were looking at). Measure the line using the same
scale you used in the drawing.
100. Parallax
Parallax: The shift in position of nearby objects when the object is viewed
from two different places.
Give it a try:
Hold out your thumb in front of your face.
Look at your thumb just through your right eye.
Now look at your thumb just through your left eye.
Does the position of your thumb change?
101. Parallax
Astronomers use a star's parallax to determine
its angles in order to triangulate the star's
distance from Earth.
The longer the baseline, the more accurate.
The longest baseline we can use from Earth is
the diameter of Earth's orbit. This means
that measurements must be taken six months apart
to achieve maximum baseline length (once in
the summer, once in the winter).
104. Spectroscope
White light can be separated into colors.
Spectroscope: is used to determine each elements black-line "fingerprint"
that stars have.
112. Doppler Effect
The Doppler effect: explains how
waves changes as an object
approaches or moves away from
you.
This is because of a change in the
frequency and wavelengths of the
wave as it moves closer and then
farther away.
113. Doppler Effect
The Doppler effect can be used to determine the speed at which an object
passes based on the light spectrum and the light waves produced.
The "red-shifted lines" shows a star moving
away from us. (red=retreat (move away))
The "blue-shifted lines" shows a star moving
towards us. (blue=beckons (comes))
No shift in lines means the star and Earth are moving in the same direction,
or is stationary.
117. Hazards of Space
As with anything in life, there are risks...
Apollo 1 - 1967 - 3 Astronauts died during a training exercise when a fire
broke out.
Challenger - 1986 - 7 Astronauts died when the shuttle exploded shortly
after take-off.
Columbia - 2003 - 7 Astronauts died when the shuttle exploded upon re-
entering Earth's atmosphere.
118. Hazards of Space
Let's think about it...
First, imagine being strapped into a small enclosed area above several hundred tones of highly
explosive fuel.
You then have to hope there is nothing to interfere with the take off.
When you make it to space you need to watch out for things like; floating debris, meteoroids, and
radiation.
When you're ready to come home, the re-entry is just as dangerous as floating around in space.
The angle you come in at cannot be too shallow (or you will bounce off the atmosphere) or too
steep (or you will enter too quickly and burn up).
Yikes...that's a lot to worry about!
121. Microgravity
Microgravity: Is NOT the absence of gravity - it
is what happens when an object is in "free fall"
This is what astronauts experience when they
orbit the Earth in the International Space
Station
Muscle mass and bone density decreases when
the body does not have to work against gravity
all the time.
Astronauts exercise a great deal each day to
keep up their fitness
122. Air & Breathing
Astronauts need oxygen but also must have carbon
dioxide removed.
Pressure must be maintained or air will not move
into the lungs - we breathe on Earth because of a
difference in pressure inside our lungs and outside
the body.
123. Life Support Systems
In order to meet create a suitable living
environment, engineers must design
complex systems (called life support
systems) to provide the proper
environmental conditions (oxygen, CO2,
temperature, humidity, pressure) and
provide water.
124. Space Junk
Space Junk: floating debris (pieces of space craft, tiny flecks of paint, parts
of rockets, satellites that are no longer working, etc.)
125. Space Junk
There are millions of pieces of space junk flying in earth’s orbit. Most orbital
debris comprises human-generated objects, such as pieces of space craft,
tiny flecks of paint from a spacecraft, parts of rockets, satellites that are no
longer working, or explosions of objects in orbit flying around in space at
high speeds.
Most “space junk” is moving very fast and can reach speeds of 18,000 miles
per hour, almost seven times faster than a bullet. Due to the rate of speed
and volume of debris in LEO, current and future space-based services,
explorations, and operations pose a safety risk to people and property in
space and on Earth.
126. Space Junk
In January, 1978, a nuclear-powered Soviet satellite crashed into the Great Slave
Lake area of the Northwest Territories. On re- entry to Earth’s atmosphere, the
satellite disintegrated, showering radioactive debris. No lives were lost, but
clean- up costs were nearly $15 million CDN and took almost 8 months!
129. Canadarm
The "Canadarm" is one of Canada's most
famous contribution to space exploration.
It debuted in 1981 on the U.S. space shuttle Columbia
and has since gone to the Hubble Space Station and the
International Space Station.
It is versatile and is manipulated by remote
control allowing astronauts to retrieve satellites or
fix different apparatus.
130. Canadarm 2
A decade later, Canada put out the
"Canadarm 2" which proved to be
bigger and stronger. It was also able
to bend around corners easier and
could grasp objects with finger-like
machinery.
This made every part of the
International Space Station
accessible.
132. Dextre
Dextre is a versatile robot that maintains
the International Space Station (ISS). Part
of Canada's contribution to the Station, it
is the most sophisticated space robot ever
built.
Dextre, also known as the Special Purpose
Dexterous Manipulator, is a two armed
robot, or telemanipulator, which is part of
the Mobile Servicing System on the
International Space Station, and does
repairs otherwise requiring spacewalks. It
was launched March 11, 2008 on mission
STS-123.
133. Satellites
Canada launched Alouette 1 in 1962 which
was the first satellite sent for non-military
purposes.
Anik 1 was sent up in 1972 and for the first
time allowed whole country coverage
in telecommunications.
Ever since, Canada has been a leader in
the development and use of
communication satellites.
134. History
1839: Sir Edward Sabine - first
magnetic observatory at the
University of Toronto. Discovered
aurora borealis was associated with
sunspot activity.
1962: Canada was the 3rd nation to
launch a satellite (Alouette 1).
135. History
1969: Apollo 11 - first manned
flight to the moon. The landing
gear was built in Canada.
1984: Marc Garneau - first
Canadian in Space
136. History
1992: Roberta Bodnar - first
Canadian female astronaut
in space.
1997: Canada provided
ramp technology for the
Mars Pathfinder. A similar
ramp that was used by
the Sojourner.
140. Political Issues
Questions relating to politics or government, such as:
Who owns space?
Who has the right to use the resources in space?
Who will determine how space will be used?
141. Ethical Issues
Questions relating to ethics or the good of all people, such
as:
Is it right to spend money on space exploration
rather than on solving problems on Earth?
Do we have a right to alter materials in space to
meet our needs?
How can we ensure that space resources will be used for
the good of humans and not to further the interests of
only one nation or group?
142. Environmental Issues
Questions relating to the
environment, such as:
Who is responsible for protecting
space environments from
alteration?
Who is responsible for cleaning up
space junk, and who should pay
for doing it?
