Why We Have Seasons
Explain that the seasons are caused by the tilt of Earth's axis during its orbit around the Sun, distinguishing this from the common misconception that seasons are caused by changing distance from the Sun
Lesson
Set out your lesson
“Earth’s axis is tilted about 23.5° from a line perpendicular to its orbital plane. During one orbit it keeps nearly the same direction in space. A hemisphere tilted towards the Sun gets more direct sunlight and longer days, giving summer. The opposite hemisphere gets winter. Distance alone cannot explain simultaneous opposite seasons. Safety: Paper only; no Sun viewing, heat lamps or exposure experiments. Stop: Stop at two orbit positions and the supplied daylight example. No temperature experiment or year-long observations.”
Bring to the table
- Paper
- Pencil
- Ruler
Extra for the adult
Worked example. In the December drawing, the north end points upper right, away from the Sun on its left. I label northern winter and southern summer. Both hemispheres are nearly the same distance from the Sun, so their opposite seasons require a tilt explanation.
Optional challenge. Explain why this mechanism gives weaker seasonal daylight changes near the equator.
What to notice. Keep the diagram and cause sentences. Note adult help keeping the axes parallel or interpreting daylight cards.
Share and support
Family records and proof options
Keep a record of your learning
Save photos, notes, and attendance. Export a proof packet for compliance or portfolio reviews.
Learning resources
Extra practice links — they do not replace Gakuva’s teaching approach.
NASA Space Place · Practice link — not the full lesson
Sun
Before you open · source notes
Sun supports Why We Have Seasons. An adult previews and guides; this is a learning page, not a scored quiz.
Free educational page, no sign-in required for the tested path.
Before you openAsk the learner one fact they learned and one question they still have.
Opening this link does not save learning or assess mastery.
Source, access and review notes
Public NASA Space Place page. An anonymous GET on 2026-11-12 returned HTTP 200 with no login or payment prompt for this URL. Opening the link does not save practice or assess mastery. An adult should preview and guide the learner.
NASA Space Place. “Sun.” External page; Gakuva does not copy, host, embed, or redistribute materials.
Unknown — link only
Check understanding
- Explains that Earth's axis is tilted at about 23.5° relative to its orbit
- Describes how the tilted axis causes one hemisphere to receive more direct sunlight in summer and less in winter
- Refutes the misconception that distance from the Sun causes seasons by noting Earth is actually slightly closer to the Sun in January
“If your child was asked why the UK is hot in summer but Australia is cold at the same time, could they explain that it's not about being closer to the Sun but about which half of the Earth is tilted towards the Sun?”
Curriculum record
- Type
- Conceptual
- Subject
- Science
- Domain
- Space Systems & Earth's History
- Age range
- Ages 11–12
Standards