Space intro lesson
Astronomy, Heliocentric, Celestial
objects
Astronomy vs. Astrology
What it is
Scientific basis
Ability to
predict future
Astrology
The study of how the
positions of celestial
bodies have influence
on life events and
behavior of people
Astronomy
The study of the origin,
movement and
behavior of the universe
astrologist
NO
Astronomer, cosmologist
YES, based on repeated
observations, simulations
and theories
NO
Zodiac signs
YES
Constellations
12, first coined by
Babylonians
88
Geocentric vs Heliocentric
• Earth at the center
• Sun at the center
Geocentric theory
• The ancient Greeks (Aristotle
included) noticed moon, sun, and
stars revolve in circle around the
Earth.
• Observationally-based but
erroneous
• Heaven is “perfect and
unchanging”- idea supported by
Catholic Church
• Galileo Galilei (1564-1642) found
Jupiter’s moon with his first
telescope; backed Corpecnicus’s
heliocentric theory
• Clashed with Church; houseconfined for the rest of his life
Supermoon on Saturday May 5 2012
Moon is a celestial object
•Celestial object: any object seen in the
sky. E.g. sun, earth, planets, comets
http://www.cbc.ca/video/#/Shows/1221254309/ID=2230765368
The Universe = all existing matter and space
considered as a whole; the cosmos.
1. How old is the universe?
13.7 billion years old
2. How do we know how old the universe is?
Edwin Hubble (1889-1953) used two
different methods:
A. Measuring speeds and distances of
galaxies and calculate backward to see
how long it took for them to reach their
current locations
B. Measuring the ages of the oldest star
clusters.
Sorting Galaxies activity
Ignore sharp point in pictures;
they are stars from our galaxy
• In group of 4, come up with
your own categories to classify
these galaxies
• What causes the difference in
galaxies’ shapes?
Galaxies
•
A galaxy is a collection of hundreds of billions of stars held
together by gravity
•A star = a hot ball of plasma that shines because of nuclear fusion
taking place at its core
•Earth is part of the Milky Way which is a spiral galaxy
•Color of galaxy depends on the age of the stars it contains
Shaped like spheres
or oval
Older & are largest
galaxies
Fewer young stars
than spiral galaxies
Flat & circular
with curving
arms
Have many
young stars
Disc-shaped with a
bulge in the middle
No particular
shape
Properties of galaxies
1. Galaxies contain about 200 billion stars
each and usually have a supermassive
BLACK HOLE in their centre
2. At least 90% of the mass in the universe
may be composed of dark matter
Black Hole
• Space where gravity is so
strong that it can pull
anything right into it.
• Masses of stars
pulled into black
hole increase the
size and mass of
the original black
hole
Dark Matter
• Invisible matter that make up 90% of the matter
in the universe. They provide the gravitational
force that hold the universe together
• Evidence for presence of dark matter:
– Stars around galaxy such as the Milky Way
revolve around the galaxy’s centre at such high
speed that they are expect to be flung off
– But they are not.
Dark matter explained: http://www.youtube.com/watch?v=nJN2X3NrQAE
Tour of the universe: 3D atlas http://ed.ted.com/lessons/a-3d-atlas-of-the-universe-carteremmart
Exit activities
Making crossword puzzle for today’s
vocab
Making inferences with “How far can
you see” article
Summarizing “Hunting Black Hole”
article