Transcript Chapter 11

We continue to learn a lot about the solar system by
using space exploration
The Sun
 All life on Earth is dependent on solar energy in the form of
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radiation. Ex: plants need it for food
Most of the Sun is made up of hydrogen. Hydrogen fuses
together to create helium plus a tremendous amount of
energy (heat, light etc). This is called a thermonuclear
reaction.
Solar radiation: energy emitted from the sun in the form
of electromagnetic radiation
The tremendous radiated energy keeps Earth warms
enough to support life.
However, too much UV light and there are consequences
The Sun
 Sun Spots: dark patches on the Sun’s surface that are
slightly cooler, about 3500°C, than surrounding areas.
 The number of sunspots on the Sun may affect Earth’s
climate, although it is still being debated
 There are records that show a lack of sunspots during
much of the 17th century, when Europe experienced a
mini ice age.
The Sun
 Solar Flares: Extremely violent eruptions of gas from the Sun’s
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surface (corona) occurs. These eruptions can last for a few hours
and heat gases to 11 000 000°C.
The gas is spewed out in every direction.
When these high energy particles rush past Earth they create an
effect called solar wind
Earth’s magnetic field deflects most of this dangerous solar wind
Some of it enters at the North and South pole, collide with gases
in the atmosphere and create the auroras (northern and
southern lights)
The solar wind can disrupt Earth’s magnetic field, disabling
satellites and even knocking out power transmission line on
Earth.
Features of the Sun
Planets
Planet: a body that must orbit one or more stars, be
large enough that its own gravity holds it in a spherical
shape, and be the only body occupying the orbital path
Terrestrial Planets: inner, rocky planets, Mercury,
Venus, Earth, and Mars
Jovian Planets: outer, gaseous planets, Jupiter, Saturn,
Uranus, and Neptune
Terrestrial and Jovian Planets
Criteria
Terrestrial Planets
Jovian Planets
Size
Small (All Earth size or
smaller)
Large (4 to 11 times larger
than Earth)
Motion
Slow spinning, small
orbits
Faster spinning, large
orbits
Composition
Solid and rocky
Gaseous
Distance from Sun
Closer
Further away
Temperature
Warmer, but
temperatures vary
Colder, but temperatures
vary
Density
Greater
Lesser
Planets…
 Closer to the sun, the temperature is warmer and the
composition is solid and rocky
 Further from the sun, the temperatures are lower and
the composition is gaseous.
 Order of the planets: My Very Educated Mother Just
Served Us Nachos (Mercury, Venus, Earth, Mars ,
Jupiter, Saturn, Uranus, Neptune)
Dwarf Planets
 Dwarf Planet is a celestial body orbiting the Sun that
is generally smaller than a planet but massive enough
for its own gravity to give it a round shape.
 They do not have enough mass and gravity to clear their
orbits of smaller debris left over from the formation of
the solar system. Pluto, Eris and Ceres
Question
 Why was Pluto demoted to Dwarf planet in 2006?
Asteroids
 Asteroids are smaller bodies that are believed to be
leftover remains of the formation of the solar system
 Most orbit the sun very similar to planets
 The main location for asteroids is in a band between
Mars and Jupiter
 Some asteroids have irregular orbits due to
gravitational attraction of the planets and collisions.
Comets
 Comets are often referred to a “dirty snowballs” made
up of ice, rock, and gas.
 They originate beyond the orbit of Neptune, at the
farthest reach of the Sun’s gravitational influence.
 Here lies a spherical cloud of small icy fragments of
debris called the Oort cloud.
 Comets are usually characterized by one or more
“tails” due to a loss of dust and ice due to exposure to
solar radiation (it starts to melt)
Path of a comet around the Sun
Comets and Periodicity
 Comets have unique orbits around the sun and tend to
follow a pattern with regards to their passage by the Earth
and Sun
 Two types of comets: Short and Long Period comets.
Short period comets orbit the Sun faster.
 Periodicity: How long it takes a comet to orbit the sun
 Research Activity 11-2c: Comet orbits and periodicity
 Meteoroids: are pieces of rock floating through space
 Meteors: (“shooting stars”) are meteoroids that burn
up as they enter Earth’s atmosphere at high speed
 Meteorites: meteors that are large enough to survive
passing through the atmosphere and they reach
Earth’s surface.
Compare and Contrast
Criteria
Asteroid
Meteor
Meteorite
Size
Sand grains to
about 1000 km
across
Sand grains
Larger than
meteor
Composition
Pieces of Rock
Pieces of Rock
Pieces of Rock
Location
Mainly the
Asteroid belt
(between Mars
and Jupiter)
Earth’s
Atmosphere
On Earth
When meteorites hit Earth
 Impact sites: the place where a relatively small object
(meteorite) has collided with a large object (planet) to
produce a fairly circular depression on the surface of
the larger object.
 Often referred to as an impact crater due to the
circular depression that was formed
 Impact sites provide evidence of meteor/asteroid
impacts on a planet
 The size of the depression created is often much larger
than the object involved in the collision.
Impact Sites
 There is a NEAR earth monitoring system that monitors
asteroids, comets etc. WHY?
 Go to: www.msss.com/small_bodies/near_new/index.html
Canadian Contributions to Space Research
 Canadarm 1: robotic arm used to retrieve and launch
many satellites and to give a stable platform for
astronauts going about their tasks in space
 Canadarm 2: a mobile remote manipulator system
designed for the International Space station. Able to
do everything Canadarm 1 does but larger and able to
move by itself to nearly every part of the station
Canadian Contributions…
 Dexterous manipulator of Canadahand: a two
armed robot that attaches to the end of Canadarm 2.
Performs task that previously required astronauts to
work outside the safety of the space station
Canadian Contributions…
 International Space Station: Sixteen countries
including Canada are involved in this space based
laboratory.
Canadian Astronauts
 Canada does not send missions into space but they
provide technology and expertise to space exploration.
 Astronaut Program in Canada is relatively new
compared with USA and Russia.
Canadian Astronauts
Roberta Bondar
Chris Hadfield
Marc Garneau
Julie Payette
Knowledge and Technology
 Knowledge of the universe is the result of centuries of
observation and data collection using more and more
advance d technologies.
 It is an ongoing process.
Technologies that have Increased
Knowledge of the Universe
 Hubble Space Telescope: Placed in Earth’s orbit and
with no air (pollution etc.) to spoil the view, this has
given amazing views of far away galaxies and stars in
space
 Using this they were able to find that the universe is
between 13 and 14 billion years old
 Light reaching its mirrors has not been distorted by
Earth’s atmosphere
Hubble Telescope
Technologies that has increased
knowledge
 The Very Large Array Radio Telescope: Made up of
27 antennas that are each 25 m across. The result is
the same as one giant radio telescope that is 36 Km
wide
 Radio telescope reveals characteristics of celestial bodies
that could not be studied using optical telescopes like
the previous two telescopes
 Dust in space makes it difficult to see light from distant
stars but this telescope is not affected by dust (uses
radio waves). Using this, we get a clearer picture.
Radio Telescope
Technologies …
 Canada-France-Hawaii Telescope: located on the
42 00 m dormant volcano in Hawaii. Above most of
the air, giving a clearer view and providing cloud free
skies.
Technologies…
 Probes : A space vehicle sent to other celestial bodies.
 Used to travel million of kilometers, to analyze distant objects
and then send information back to Earth
 Spectroscopy: A spectroscope is an optical instrument
that acts like a prism to separate light into its basic
component colors (a spectral pattern).
 This allows astronomers to view the spectral pattern
produced by individual stars.
 Spectral lines stand out across the bands of color in a star’s
spectrum
 The dark lines tell you the wavelength of the visible light
given off by a star
 Tells about the types of atoms giving off light, and used to
determine what the star is made up of
Technologies…
 Adaptive Optics
 With Earth based telescopes the view can be distorted
by the Earth’s atmosphere (so stars appear to twinkle)
 Telescopes can now be made with mirrors to overcome
this distortion. This design is called adaptive optics
 A computer monitors the atmosphere while the
telescope is being used and small mechanisms slightly
change the shape of the mirror to compensate for this
distortion
Technologies and underlying
science
Technology Chemistry
Biology
Physics
Geology
Rockets
Space Suits
Satellites
Probes
Rovers
Optical
Telescopes
Radio
Telescopes
The next Six slides can help the students fill out this table.
Other
Technologies and underlying
science used to Explore Space
 Rocket is a system used for transporting materials and
astronauts into space
 Filled with explosive fuels (chemistry)that combine to
generate thrust, the force (physics) that pushes against
the rocket to get it to move
 As fuel is used up, some of the rocket is lost to make it
lighter
Technologies and underlying science
 Space Suits: acts as a smaller space ship, providing
oxygen (chemistry) to breathe
 Contain a communication system to talk to each other
and people on Earth (radio waves, physics) a cooling
system and a system to simulate the air pressure on
Earth’s Surface (air pressure, physics)
Technologies and underlying science
 Satellites are electronic devices put in orbit around
Earth to relay information.
 Communications satellites use electromagnetic
radiation is used to send information from one place
to another (involves physics)
Technologies and underlying science
 Rovers: are small movable probes designed to land on
a planet, explore and test the surface and send the
information back to Earth by radio waves.
 They conduct experiments in geology (determining
the make up of rocks) and biology (looking for signs of
life)
Technologies and underlying science
 Optical telescopes: use the property of light
(physics) to get a better picture of the universe.
 Hubble space telescope is in Earth’s orbit. This also
uses electromagnetic waves from the field of physics to
send information back to Earth.
Technologies and underlying science
 Radio Telescopes: Radio signals coming from distant
objects are collected and converted to electrical
symbols (physics again) and analyzed.
Core Lab
Designing a Space Station