Transcript this It`s in the News! resource

Astronomers have
discovered a new
planet which could
support human life.
It’s in its star’s
‘Goldilocks Zone’,
orbiting at distance so
that it’s not too hot and
not too cold for liquid
water to exist.
The planet, called Gliese 581g, is about three times the
mass of the earth with a radius about 1.5 times as large.
It orbits its star once every 36 days.
It is about 120 billion miles away from the Earth.
Draw a scale diagram or make a scale model showing
the Sun, the Earth and Gliese 581g.
The Earth has a radius of about 4 000 miles. The Sun is
about 93 million miles away from Earth and has a radius
of about 430 000 miles.
It takes light about 20 years to travel the 120 billion miles
from Gliese 581g to Earth.
The space shuttle travels at 17 500mph. How long would
it take for a craft like the shuttle to reach the planet from
Earth?
If a crew of 20 people left Earth for Gliese 581g, how
many people do you think would arrive? What relation
would they be to the original crew?
It’s in the News!
Star Trekkin’
Teacher Notes
Star Trekkin’
Introduction:
Astronomers using the Keck Observatory in Hawaii have found what they consider to be the most suitable planet to support life so far.
Scientists believe that the planet, called Gliese 581g (named after its star, Gliese 581), is made of rock, like the Earth, and sits in the ‘Goldilocks Zone’ of its
sun, where it is neither too hot nor too cold for water to exist in liquid form – widely believed to be an essential precondition for life to evolve.
A video of scientists talking about the planet can be found on website of The Independent.
Content objectives:
This context provides the opportunity for teachers and students to explore a number of objectives. Some that may be addressed are:
•
choose and use units of measurement to measure, estimate, calculate and solve problems in a range of contexts
•
communicate own findings effectively, orally and in writing, and discuss and compare approaches and results with others; recognise equivalent
approaches
•
identify the mathematical features of a context or problem; try out and compare mathematical representations; select appropriate procedures and tools,
including ICT
•
use rounding to make estimates and to give solutions to problems to an appropriate degree of accuracy.
Process objectives:
These will depend on the amount of freedom you allow your class with the activity. It might be worth considering how you’re going to deliver the activity and
highlighting the processes that this will allow on the diagram below:
Activity:
There are three activities to choose from.
The first activity gives students information about size of Gliese 581g relative to the Earth and gives the distances between the Earth and the Sun and the Earth and Gliese 581g.
Students are asked to construct a scale model of diagram. This initially simple activity will prove to be challenging, if not impossible, because of the vast differences in the
numbers (representing the Earth with its 8 000 miles radius on the same scale as the 120 billion mile distance). However, students might be able to construct a comparison that
has a meaning for them (for example, if the Earth was a golf ball then the sun would be…).
The second activity is a closed activity in which students will need to make some simple assumptions. The students are given the speed of the space shuttle and asked how long
it would take to reach Gliese 581g. This activity will give them an opportunity to explore the assumptions that they are forced into making and will provide some structure for the
third activity.
In the third activity, students are asked to estimate the number of people that would arrive at Gliese 581g if a crew of 20 people were to leave the Earth. This activity allows
students to construct a more complex model than the second activity and gives a greater opportunity to work with and justify a range of estimates and assumptions.
Differentiation:
The content of this task is relatively low, the organisation and logic of the task can, however, end up being quite challenging. You may decide to change the level of challenge for
your group. One of the objectives for this task might be for students to experiment with different approaches to a problem, to show resilience. It is worth considering what
pedagogy would support this objective.
To make the task easier you could consider:
•
only using one of the activities with the group
•
setting the size of the Earth as, for example, a mm diameter dot and asking students to construct or describe the diagram from this fixed point
•
scaffolding the task for the students, for example, in activity three ask them to discuss in pairs what assumptions they’ll have to make and take feedback before they start
to work with numbers.
To make the task more complex you could consider:
•
removing the scaffolding, maybe not showing the group the second activity but sharing the information with them orally
•
ask students to consider the size of the ship that would be needed to ensure that there’d be enough space to support the crew as they grow.
This resource is designed to be adapted to your requirements.
Working in groups:
This activity lends itself to paired work and small group work and, by encouraging students to work collaboratively, it is likely that you will allow them access to more of the key
processes than if they were to work individually.
You will need to think about how your class will work on this task. Will they work in pairs, threes or larger groups? If pupils are not used to working in groups in mathematics you
may wish to spend some time talking about their rules and procedures to maximise the effectiveness and engagement of pupils in group work. (You may wish to look at the SNS
Pedagogy and practice pack Unit 10: Guidance for groupwork.) You may wish to encourage the groups to delegate different areas of responsibility to specific group members.
Assessment:
You may wish to consider how you will assess the task and how you will record your assessment. This could include developing the assessment criteria with your class. You
might choose to focus on the content objectives or on the process objectives. You might decide that this activity lends itself to comment only marking or to student self
assessment.
If you use the APP model of assessment then you might use this activity to help you in building a picture of your students’ understanding.
Assessment criteria to focus on might be:
•
use and interpret mathematical symbols and diagrams (using and applying mathematics level 3)
•
search for a solution by trying out ideas of their own (using and applying mathematics level 4)
•
draw simple conclusions of their own and give an explanation of their reasoning (using and applying mathematics level 5)
•
justify generalisations, arguments or solutions (using and applying mathematics level 7)
•
distinguish between practical demonstration and proof; know underlying assumptions, recognising their importance and limitations, and the effect of varying them (using
and applying mathematics level 8).
Probing questions:
These might include:
•
what’s your starting point? What assumptions will you have to make?
•
can you make a very simple estimate?
•
will the shuttle always travel at the same speed? Will any variation make a significant difference to your solution?
•
what if there were limitations on the number of children that couples were allowed on the ship? What difference would that make to the total number
arriving? Can you give an upper and lower estimate?
•
how much of an impact does the gender split of the initial crew make on the number of people arriving at the planet?
You will need:
The PowerPoint presentation: there are four slides:
The first slide sets the scene
The second slide gives information about the size of Earth, the Sun and Gliese 581g, and invites students
to create a scale model or drawing
The third slide gives information about the distance between Earth and Gliese 581g and the speed of the
space shuttle and asks students to calculate how long it would take to reach the planet
The final slide poses the question “If a crew of 20 people left Earth for Gliese 581g, how many people do
you think would arrive? What relation would they be to the original crew?”