SILO 3.2 (DRAFT)Year 3, Term 2: SatellitesFocus: Angles Scope and sequence: Heliocentric model |
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Learning
intention: Students
explore night and day and seasonal changes in relation to
orbiting bodies
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Overview: The Earth is a
satellite which rotates on its own axis each day while revolving
around the Sun each year. Students will come to see how
this rotation causes us to experience night and day. The
angle of the Earth's rotation combined with its revolution
around the Sun is why we experience different seasons throughout
the year. This unit also looks at mechanical satellites
which are used for global communications.
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NSW Syllabus
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Australian Curriculum (version
9.0)
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"A student investigates regular
changes caused by interactions between the Earth and the Sun,
and changes to the Earth’s surface." (ST2-10ES-S)
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"Students learn to describe the
movement of Earth and other planets relative to the sun and
model how Earth’s tilt, rotation on its axis and revolution
around the sun relate to cyclic observable phenomena, including
variable day and night length." (AC9S6U02)
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The central idea which runs throughout this unit is that a satellite is a moon, planet or machine that orbits a planet or star. 'Orbit' is a revolution around another object as distinct from rotation which involves spinning around its own axis. The following video (1:50) explains all of this in relation to night and day.
Sir Isaac Newton used a cannonball analogy to explain the orbit of the Moon around the Earth as shown in the image below.
Brian Brondel - Own work, CC BY-SA 3.0,
Why doesn't gravity cause the Moon to collide with the Earth? |
Direction is relative as shown in this video (0:47) where
clockwise and anti-clockwise depend on your frame of reference.
In the animated GIF below you can see that the movement in in a clockwise direction.
By Willow W - Own work, CC
BY 3.0, https://commons.wikimedia.org/w/index.php?curid=3397590
The following photo has the numbers going
anticlockwise. Look carefully for other details in the photo to explain
why this might be the case. (Hint: Think in terms of geography.)
https://en.wikipedia.org/wiki/Sundial#/media/File:Sundial_in_Supreme_Court_Gardens,_Perth.jpg
The Coriolis effect describes the pattern of deflection taken by objects not firmly connected to the ground as they travel long distances. This explains why tornadoes spin in different directions in the Northern and Southern Hemispheres as the Earth is moving much faster at the equator than at the poles.
The following video (1:20) involves placing a glue stick on a spinning 'Lazy Susan' to demonstrate the Coriolis effect.
Life is different at the poles
(Jacobs & Robin, 2016, p. 273)
Indigenous knowledge
The arrangement of these rocks on Wadawurrung country
mirrors the changing position of the setting Sun throughout the year.
The Heliocentric model is the idea that the Earth revolves around the Sun (as opposed to the Geocentric model where the Sun revolves around the Earth). The Heliocentric model was very controversial during the Renaissance (15th and 16th centuries) and was a key ingredient in the Scientific revolution. However, the following video (2:16) featuring Eratosthenes (276 BCE – 194 BCE) shows how this idea was discussed much earlier.
This animation (0:56) was made by a student in Year 6 and
it explains how satellites work.
How big is our universe? This video (7:05) by the
BBC shows just how big the universe is.
Elliptical orbits
Drawing ellipses