Alien
Probe
Homework and
Assessment for Learning
Activity from the Alien unit © upd8 wikid, built by cracking science, 2009
Homework 1
Modelling our Solar System
Scientists use models to represent science ideas simply. Models help us to
picture things that are very big, like the Solar System, or very small, like cells.
They help scientists to make explanations and predictions.
No model is perfect. In this homework you will evaluate the good and bad
points of the Solar System model you made.
1
We wanted our model to help us explain…
2
Our model helped others to understand what we were explaining
because…



3
Two things I would do to make the model better for helping others to
understand are…


4
One problem with our model that we could probably never improve is…

Solar System
Activity from the Alien unit © upd8 wikid, built by cracking science, 2009
1
Homework 2
Mars Lander
Space scientists have sent several landers to Mars. Some expeditions were
more successful than others.
In this homework, you will discover more about these trips. What have we
learnt from them? What makes a successful Mission to Mars?
Your task
1 Use the web links below to find out about the Phoenix Mars Lander.
Produce a report to answer these questions:

When did Phoenix land on Mars?

Describe two of its important discoveries.
http://news.nationalgeographic.com/news/2008/09/080929-marssnow.html
http://science.howstuffworks.com/water-on-mars2.htm
2 Look at the list of Mars missions on the web link below.
Answer these questions:

Give the name and date of an unsuccessful mission to Mars.
What went wrong?

Which countries have been involved in missions to Mars?
Why do you think some countries choose not to get involved?
http://www.unb.ca/passc/missions/marsmissions.html
Lander
Activity from the Alien unit © upd8 wikid, built by cracking science, 2009
2
Assessment for Learning task
Pluto: a planet no more
The International Astronomical Union (IAU) has downgraded Pluto from being
our ninth planet to the category dwarf planet. Many people are angry about
this decision.
Should Pluto be reinstated as a planet?

Do the tasks to help you decide.

Complete the report form.

Look at the hints to help you write the report to the best grade you can.
Task 1
Study the data cards about nine big objects in the Solar System.
Use the report form to record your findings as you work through the
following:

Arrange the objects in order of size.

Put them in order of discovery date.

Put them in order of distance from the Sun.

Group them by orbital type.

Group them by type of object.
Task 2

Decide on three characteristics that a body must have in order to
qualify as a planet.

Complete this section on the report form.

Does Pluto have these characteristics?

Report your conclusions on the report form.
Task 3
The IAU decided that to be a planet, a body must:
 Orbit the Sun
 Have an orbit that is circular (or nearly)
 Not cross the orbits of other bodies.

Do you agree with the decision to reclassify Pluto as a dwarf planet?

Report your conclusions on the report form.
Pluto – a planet no more
Activity from the Alien unit © upd8 wikid, built by cracking science, 2009
3
Assessment for Learning task
Pluto Report Form
Task 1
The patterns I can see are…
Comparison (using data cards)
Planets
Dwarf planets
I think astronomers will / will not discover more dwarf planets
because…
Task 2
To be a planet, a body must have…
Does Pluto have
this?
1
2
3
Task 3
My personal comments on the action of the IAU to reclassify Pluto…
Pluto – a planet no more
Activity from the Alien unit © upd8 wikid, built by cracking science, 2009
4
Assessment for Learning task
Data Cards
Object: Mercury
Time to orbit Sun: 88
days
When discovered:
2000 BCE
Diameter/km: 4800
Distance from
Sun/AU: 0.4
Orbit and notes: Orbit
nearly circular. Has
cleared its orbit of other
objects.
Object: Pluto
Time to orbit Sun: 250
years
When discovered:
1930
Diameter/km: 2200
Distance from
Sun/AU: 40
Orbit and notes: Orbit
inclined to the orbits of
other planets. Elliptical
(30-50 AU). Crosses
orbit of Neptune.
Classification: Planet
Classification: Dwarf
Planet
Object: Charon
Object: Eris
Time to orbit Sun: 250 Time to orbit Sun: 560
years (with Pluto)
years
When discovered:
When discovered:
1978
2003
Diameter/km: 1200
Diameter/km: 3000
Distance from
Distance from
Sun/AU: 40
Sun/AU: 67
Orbit and notes: Orbits Orbit and notes:
as a moon of Pluto. Very Elliptical (40-100 AU).
big – almost Pluto’s
Crosses orbits of
‘twin’.
Neptune and Pluto. Was
called Xena.
Classification: Moon of Classification: Dwarf
Dwarf Planet (Pluto)
Planet
Object: Europa
Object: Mars
Time to orbit Sun: 11.8 Time to orbit Sun: 1.9
years (with Jupiter)
years
When discovered:
When discovered:
1610
when humans first
looked at stars
Diameter/km: 3100
Diameter/km: 6800
Distance from
Distance from
Sun/AU: 5.0
Sun/AU: 1.5
Orbit and notes: Orbits Orbit and notes: Orbit
as a moon of Jupiter
nearly circular. Has
cleared its orbit of other
objects.
Classification: Moon of Classification: Planet
Planet (Jupiter)
Pluto – a planet no more
Activity from the Alien unit © upd8 wikid, built by cracking science, 2009
Object: Ceres
Time to orbit Sun: 4.6
years
When discovered:
1801
Diameter/km: 1000
Distance from
Sun/AU: 2-3 (in the
asteroid belt between
Mars and Jupiter)
Orbit and notes: Does
not have a clear orbit.
Was the largest asteroid.
Classification: Dwarf
Planet
Object: Sedna
Time to orbit Sun:
10,500 years
When discovered:
2004
Diameter/km: 1800
Distance from
Sun/AU: 90 at closest
Orbit and notes: Very
very elliptical. Crosses
orbits of small solar
system bodies.
Classification: Dwarf
Planet
Object: Io
Time to orbit Sun: 11.8
years (with Jupiter)
When discovered:
1610
Diameter/km: 3600
Distance from
Sun/AU: 5.0
Orbit and notes: Orbits
as a moon of Jupiter
Classification: Moon of
Planet (Jupiter)
5
Assessment for Learning task
To be graded level 4, 5 or 6 you need to
4:
To get level 4, you need to…
…describe patterns in Solar System objects.
…start to make conclusions based on patterns in the data.
5:
Do everything for level 4 plus…
…make conclusions that agree with the evidence.
6:
Do everything for level 5 plus…
…use more than one science idea to explain the conclusions.
…explain why some evidence does not fit with the conclusions.
7:
Do everything for level 6 plus…
…identify limitations in the data.
…decide whether there is enough data to properly support your
conclusions.
…explain how evidence supports the idea that Pluto is not a planet.
Pluto – a planet no more
Activity from the Alien unit © upd8 wikid, built by cracking science, 2009
6
Peer-assessment guidelines for AfL task
Is it level 5?
Does it...
Describe patterns in Solar System objects?
Make a conclusion about whether Pluto is a planet that
agrees with the evidence?
NO -->
Award level 4 and explain what needs to be
added.
YES -->
Try for level 6
Is it level 6?
Does it...
Use more than one science idea to explain the
conclusion about whether or not Pluto is a planet?
Give an example of a piece of evidence that does not fit
with the conclusion.
NO -->
Award level 5 and explain what needs to be
added.
YES -->
Try for level 7
Is it level 7?
Does it…
Identify any problems with the data?
Say whether there is enough data to properly support
the conclusion?
Explain how the evidence supports the idea that Pluto is
not a planet?
NO 
Award level 6 and explain what needs to be
added.
Yes 
Award level 7 and explain what would make it
even better.
Pluto – a planet no more
Activity from the Alien unit © upd8 wikid, built by cracking science, 2009
7