Science and Technology K–6 · Years 1–2
Star patterns: finding the Southern Cross with a star wheel
Earth and Space (NSW 2017); Science understanding, Earth and space sciences, and Science as a human endeavour (ACARA v9)
The idea
Stars form patterns that keep their shape while the whole sky turns through the night and shifts through the year.
Safety card
Hazards
- Outdoors after dark
Controls
- With a family adult; torch with red cellophane; no roads
Note
No chemicals or heat. Record the activity on the school's risk assessment (Primary School RiskAssess, Ecosolve Australia, riskassess.com.au).
What you need
- A printed southern-sky star wheel (planisphere) set for the observer's latitude, assembled in class
- A red-cellophane torch so eyes stay dark-adapted
- A family task sheet: date, time, a drawing of the Southern Cross and the two Pointers, and where they sat (low, high, left, right) over the same landmark about an hour after sunset and again two hours later
How to do it
- Set the star wheel to tonight's date and the time of the first look (about an hour after sunset). Find the Southern Cross and the two Pointers on the wheel.
- Outside at that time, face south, find the pattern, and draw its position over a landmark.
- Two hours later find it again and draw it. Has it moved, and has its shape changed.
- Back in class compare drawings and set the wheel a month ahead to predict where the Cross will be at the same clock time then, taking an hour off the clock time if daylight saving is on.
What you should see
The Cross and Pointers keep the same shape but have turned about the south celestial pole between the two looks (about 30 degrees, since the sky turns a full circle in a little under 24 hours); a month later at the same clock time the pattern is about 30 degrees further round (30 days times 0.99 degrees a day), unless daylight saving starts or ends in between. The sky turns about 15 degrees an hour, so when clocks go forward (the first Sunday in October in NSW) the same clock time comes an hour earlier by the sky and the shift is only about 15 degrees; when clocks go back (the first Sunday in April) it is about 45 degrees. A star wheel is usually marked in standard time, so an hour is taken off a daylight-saving clock time before setting it. At some times of year the Cross sits low in the south in the evening, where trees or buildings can hide it; the star wheel shows where to look. The learner knows it worked when the two drawings show the same shape in different positions and the star wheel agrees with both.
What changes
This activity lists no variables to change, measure and keep the same.
Common misconceptions
Each of these ideas is wrong, and the activity is a chance to test it.
- Stars move about on their own each night.
- The Southern Cross is always upright.
Curriculum references
The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.
- Science and Technology K-6 Syllabus (2017), NESA. Current syllabus; NESA's timeline is 2026 plan and prepare, 2027 start teaching the 2024 syllabus. Code read from the official syllabus document on 2026-09-22.ST1-10ES-S
- Science and Technology K-6 Syllabus (2024), NESA. Implementation from 2027, so this code describes the future syllabus. Code read from the outcomes page on 2026-09-22.ST1-SCI-01
- Australian Curriculum v9AC9S2U01AC9S2H01AC9S2I03AC9S2I06
Sources
The pages the author read to write this activity.