Transcript Chapter 30: What is Astronomy?

Integrated Science
Unit 11, Chapter 30
Unit Eleven: Astronomy
Chapter 30 What is Astronomy?
30.1
Cycles on Earth
30.2
Tools of Astronomy
Chapter 30 Learning Goals
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Relate keeping track of time to astronomical cycles.
Predict how the moon will appear based on its orbital position.
Describe what causes the seasons.
Describe what causes eclipses.
Convert large numbers to scientific notation.
Name the differences between stars, planets, galaxies, and the
universe.
Convert between kilometers and light years.
Explain how refracting and reflecting telescopes work.
Name some telescopes that examine other types of electromagnetic
waves.
Describe how satellites, space probes, and piloted spacecraft are
used in astronomy.
Chapter 30 Vocabulary Terms
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axis
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rotation
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calendar galaxy
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satellite
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light year
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scientific notation
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lunar eclipse
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solar eclipse
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planet
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star
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reflecting telescope
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telescope
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refracting telescope
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universe
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revolution
30.1 Cycles on Earth
Key Question:
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How do we keep
track of time?
*Read text section 30.1 AFTER Investigation 30.1
30.1 Cycles on Earth
A
calendar is a means of
keeping track of all the days
in a year.
 The
development of a
calendar came from a need to
be able to predict the
seasons, annual floods, and
other cyclical occurrences in
communities’ lives.
30.1 Phases of the Moon
 The
moon moves around Earth in a path called
an orbit.
 How
the moon appears to Earth dwellers at
different positions in its orbit is shown below:
 The
phases of the moon occur because of the
positions of Earth, the moon, and the sun.
30.1 Cycles on Earth
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Earth’s axis is the
imaginary line that
passes through its
center and connects the
North and South poles.
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Earth’s spinning on its
axis is called rotation
and it brings about day
and night.
30.1 Cycles on Earth
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The movement of one
object around another in
space is called revolution.
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Earth’s path as it revolves
around the sun is called its
orbit.
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One year (365.25 days) is
the amount of time it takes
Earth to complete one
revolution around the sun.
What causes seasons?
30.2 Tools of Astronomy
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The closest star to our sun, Alpha
Centauri, is 41,000,000,000,000
kilometers away.
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Trying to write out astronomical
distances requires a lot of zeros.
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Scientific notation is a
mathematical abbreviation for
writing very large (or very small)
numbers.
30.2 Tools of Astronomy
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The universe is defined as everything that exists,
including all matter and energy.
A star is a sphere of gas that undergoes a process
called fusion. This process releases so much energy,
the star gives off very bright light.
 A planet is a large, spherical piece of matter that
revolves around a star.
30.2 Tools of Astronomy
A
light year is the distance light travels in one
year through space (9.46 × 1012 kilometers).
 ex.
How many light years away is Alpha
Centauri, the closest star to our sun?
—
Remember this star is 4.1 trillion km away...
4.1 x 1013 km = ? light years
30.2 Tools of Astronomy
4.1 x 1013 km =
4.1 x
1013
km
x
1
? light years
light year
9.46 x 1012 km
=
4.3
s
30.2 Tools of Astronomy
 A satellite
is an object that
travels in orbit around
another object.
 The
Hubble Space
Telescope (or HST) is a
satellite that orbits Earth.
This powerful telescope
sends images from deep
space to computers back
on Earth.
30.2 Tools of Astronomy
 Space
probes are unmanned spacecraft that
carry scientific instruments on board.
30.2 Tools of Astronomers
 Space
shuttles are piloted
spacecraft that launch from
rocket “boosters” and can land
back on Earth like an airplane.
 A space
shuttle consists of three
big components: two solid rocket
boosters (SRBs), an external fuel
tank, and an orbiter.
30.2 Tools of Astronomy
Key Question:
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How does a telescope work?
*Read text section 30.2 BEFORE Investigation 30.2