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Space Explorations
FINAL EXAM REVIEW
Key Concepts
 Technologies for space
 Composition and
exploration and
observation
 Reference frames for
describing position and
motion in space
 Satellites and orbits
 Distribution of matter
through space
characteristics of bodies
in space
 Life-support
technologies
 Communication
technologies
Frames of Reference
 Ancient astronomers learned a lot about the heavens
without much, if any, technology.
 Earth was the first frame of reference people used.
 Frame of reference: a set of axes of any kind that
is used to describe the positions or motions of things
Locating Stars in the Sky
 Altitude-azimuth co-ordinates are a set of co-
ordinates used to locate a celestial body relative to a
fixed Earth (as though the celestial bodies are
circling Earth)
 Altitude measures the angle of elevation of an
object above the horizon
 Azimuth measures the compass direction, in
degrees, clockwise from North
Models of the Universe
 Careful measurements of planetary motions led to two
conflicting theories of the universe – geocentric and
heliocentric.
 Geocentric: a model of the universe that places Earth at
the centre with the Sun, moons, and planets revolving
around it
 Heliocentric: a model of the universe that places the
Sun at the centre with Earth, the planets, and moons
 The invention of the telescope enabled astronomers to
make more precise measurements of celestial objects,
and the heliocentric theory won out.
Spectroscopes and Spectroscopy
 The electromagnetic spectrum arranges radiation
from the lowest energy to the highest energy.

Radio waves, microwaves, infrared light, visible light,
ultraviolet light, x-rays, gamma rays
 The invention of the spectroscope enabled
astronomers to infer the composition of stars.
 Spectroscopy also enables astronomers to find out
the direction of motion of celestial bodies because of
the Doppler effect.
Radio Telescopes
 Radio signals come from the sky. Radio astronomers
made many more discoveries about celestial bodies
by analyzing radio waves.
 Radio telescope images are not affected by dust,
clouds, weather, Earth’s atmosphere, or visible light
(can be used day or night). This gives them an
advantage over optical telescopes
Applications
 The distances to the nearest stars are found with
parallax and triangulation.
 Telescopes of all types have been made bigger over
the years. They have been connected through the use
of computers. Some telescopes have been placed in
space.
Technological Developments
 Rockets were designed for war and are now used for
peaceful applications. All of the things we put in
space need rockets to get them there.
 Computers are important for space technology. They
are used to calculate orbits, store and manipulate
images, and to receive and act upon instructions
from Earth.
Technological Developments
 The Hubble space telescope is one of a series of
space-based observatories planned or launched.
Several other space telescopes now exist.
 Space telescopes produce clearer images than land-
based telescopes because they do not experience
interference from Earth’s atmosphere, clouds, and
weather.
Satellites
 Scientists are studying Earth from space with satellites.
These satellites may be in low Earth orbits, or in
geosynchronous orbits. This is called remote sensing.

Low Earth Orbit: satellites are placed 200—800 km above the
ground, and complete one orbit of Earth in about 1.5h

Geosynchronous Orbit: orbit of satellites placed about 36000 km
above the ground, directly above the equator, orbiting Earth once
every 24 h
 The global positioning system (GPS) is a fleet of satellites
used by people to locate their position on Earth.
Space Exploration
 The Sun, Moon, and every planet have been visited
by at least one Earth spacecraft. We have some closeup data on these as a result.
 The main focus of a human presence in space at this
time is to occupy a space station. Canada is a partner
in this endeavor, supplying many technological
devices and astronauts as mission specialists.
Notable Firsts
 First human in space: Yuri Gagarin
 First woman in space: Valentina Tereshkova
 First human on the Moon: Neil Armstrong
 First Canadian in space: Marc Garneau
 First Canadian woman in space: Roberta Bondar
 First spacewalk: Alexei Leonov
 First Canadian spacewalk: Chris Hadfield
 Longest time spent in space: Scott Kelly
Humans in Space
 Humans travelling in space have many challenges
facing them, including limited supplies of food,
water, oxygen, medicines, and fuel
 The effects of living in microgravity can also cause
bones to weaken, cardiovascular systems to weaken,
and other negative effects.
 Astronauts sometimes also deal with depression,
loneliness, and isolation when traveling in space.
What to Expect on the PAT
From this unit:
 10 multiple choice questions
 1 numerical response question
 5 “knowledge” questions
 6 “skills” questions
Examples of Knowledge Questions
Parallax and triangulation
can be used to determine the
A. Distance between a star
and a planet
B. Magnitude of a star’s
brightness
C. Speed a planet is orbiting
a star
D. Composition of a star or
planet
The Hubble Space Telescope
produces clearer images than
similar telescopes that are
used on Earth because
A. the Hubble Space
telescope is travelling in a
geosynchronous orbit
B. the Hubble Space
Telescope is closer to the
stars that it is viewing
C. there is no interference
from Earth’s atmosphere
in space
D. there is no air pressure in
space
Examples of Skills Questions
What is
the student
in the
illustration
most likely
trying to
determine?
A. The altitude of the sphere
B. The azimuth of the sphere
C. The distance to the sphere
D. The diameter of the
sphere
Which of the celestial objects
listed above poses the greatest
danger to space exploration
technologies and astronauts in
the space environment?
A. Asteroid
B. Meteoroid
C. Meteor
D. Meteorite