Manitoba Grade 6 Science Earth, Moon and Sun

Seasons Explorer

A daylight investigation · 2026

Same Earth. Different daylight.

How does Winnipeg’s daylight change through the year? Predict, compare two dates, then explain the pattern.

1 At 23.4° tilt, more daylight in…

Say why to a partner, or think it through.

2 Compare at the same tilt

Start with 23.4°. Then test 0°.

Orbital modelAxis direction stays fixed through this year

Not to scale. The Sun and Earth are drawn far too big for this orbit. The orbit's shape is true: almost a circle. Earth is turned so Winnipeg is at noon.

23.4°

Tilt is measured from the line perpendicular to the orbit plane. The axis keeps nearly the same direction through one year.

Distance from the Sun

152.0 million km

Only 3% change all year, and closest in January.

Choose a date

Teacher notes

Where it fits

Built for the Manitoba Grade 6 Science Earth-Moon-Sun unit. SCI.6.E.10: the relationship among the tilt of Earth's axis, revolution around the Sun, number of daylight hours, and seasonal change. SCI.6.E.9: seasons (solstice, equinox), revolution, orbit. Supports SCI.6.E.8 (sunrise, sunset, length of a day).

  • Lesson 2, Shadows and the Sun's Path: the shadow-stick view before or after Investigation 2 (Shadow Tracker).
  • Lesson 6, What Causes the Seasons? "Try this 2" is Investigation 4 on screen: the distance hypothesis, tested with USNO dates and NASA distances.
  • Lesson 7, Tilt, Sunlight and Daylight: the tilt control and "Try this 3", alongside Investigation 5 (flashlight at 90° and 20°).

The misconception to surface

Many students (and adults) believe summer happens because Earth is closer to the Sun. NASA calls this idea sensible but incorrect. The evidence on screen: Earth is closest on 3 January 2026 and farthest on 6 July 2026 (USNO), a change of about 5 million km, roughly 3%. Manitoba is in winter at the closest point. The Southern Hemisphere has summer on the same day, at the same distance.

Facilitate a ten-minute investigation

Invite a prediction before revealing the table. Visit June and December with the date buttons; ask partners to point to the axis and read out daylight and noon height. Open the evidence, then repeat at 0° while keeping the place and dates fixed. Finish with the Southern Hemisphere transfer check. A changed prediction is useful evidence of reasoning, not a score.

What to ask

  1. Before pressing Play: "When do you think Earth is closest to the Sun?" Record predictions, then check the distance card.
  2. "Watch the gold ring on the globe. What does the lit part of the ring tell you?" (It shows approximately how the daylight fraction changes. The geometric ring does not include NRC’s refraction and upper-edge daylight conventions.)
  3. "Look at the small axis arrows at the four marked dates. Does the axis ever change direction?"
  4. "Set the tilt to 0°. What happened to the graph? To the shadow?" Then 40°: "What would Manitoba summers and winters be like?"
  5. "Churchill is farther north. Whose daylight changes more through the year? Why?"

How to run it

  • Project it full screen. Everything works with a mouse, a touch screen or the keyboard: Space plays or pauses, ← → move one day, Page Up Page Down move one week, T toggles tilt 0° / 23.4°.
  • Drag the 3D view to look from any side; "Follow Earth" flies in close so the tilt and the day-night line are easy to see.
  • No login. Investigation choices stay only in this open page and are cleared by Reset investigation or reload. The downloadable app folder can run offline; this hosted page must first load its files.

Where the numbers come from

  • Sunrise, sunset, daylight: National Research Council Canada sunrise/sunset calculator, full-year 2026 tables for Winnipeg and Churchill, every day. Daylight = sunset minus sunrise. Times are Central Standard Time; NRC says to add one hour when daylight saving time is in effect.
  • Noon Sun height and shadow: NRC sun-position tables for the 21st of every month of 2026 (the highest altitude NRC lists that day). On other dates the height is estimated between those monthly values (checked to within about 0.2°), and the shadow is computed from it: shadow = 1 m ÷ tan(height).
  • Tilt 23.4°: NASA Science, Earth: Facts. Closest and farthest distances (91.4 and 94.5 million miles, shown in km): NASA Space Place, What Causes the Seasons? Distances on other dates follow Earth's elliptical orbit between those two values.
  • Solstice, equinox, closest and farthest dates: U.S. Naval Observatory, Earth's Seasons and Apsides 2026 (UTC-6).
  • What-if tilt: any tilt other than 23.4° switches to a geometry model (it matches NRC's Winnipeg daylight within a few minutes at 23.4°). Sunrise and sunset clock times are not shown in what-if mode.

Honest limits

  • Sizes are not to scale; the orbit shape is. The globe shows the day side, the night side and a latitude-longitude grid; it does not draw continents.
  • Data covers 2026. Dates in other years differ by a day or so.
  • The model ignores weather, clouds and the lag between the solstice and the warmest weeks. At zero tilt, daylight and noon height do not vary with the date in this model; this is not a claim that Earth–Sun distance has no effect on incoming energy. Sunrise-to-sunset includes the Sun’s apparent size and refraction, so a zero-tilt day here is slightly longer than 12 hours.

Read the sources

Source links require internet. Local 2026 tables and calculation notes are included with the authoring source.

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