Sun and Seasons Lab teaching notes
For middle school Earth science teachers, co-op leaders and parents. The reasons for the seasons in one period, a second period for sunlight and a real shadow, and the wrong ideas students bring, with where the app answers each one.
Using this with a class? Make a free class and add your students yourself: each gets a username and password, with no email or Google account needed. Or give them one join code. Using Google Classroom? Post the link there; with a free class, the link also puts each student in your class, so you see their work. mytekDev is also available from the Google Workspace Marketplace, so your school's Google admin can install it for everyone.A first lesson: One period: predict why summer is warmer, watch a stick's shadow at noon in June and December in your town, find the day Earth is closest to the Sun, compare with Sydney, and predict again. A second period for the Sunlight chapter and a real shadow outside.
Set up a free class Share to Google Classroom- About these notes
- The reasons for the seasons in one period
- Sunlight and a real shadow, a second period
- What students get wrong, and where the app answers it
- What the app simplifies, on purpose
- Middle school and high school
- The sheet, the puzzles and the setup
- Standards
About these notes
Sun and Seasons Lab shows one moment three ways: a schoolyard in the student's own town with a stick and its shadow, Earth going round the Sun with its tilted axis, and the town's daylight and noon Sun height through the year.
It is written for the seasons part of MS-ESS1-1: develop and use a model of the Earth-sun-moon system to describe the cyclic patterns of lunar phases, eclipses of the sun and moon, and seasons. MS-ESS1-1 has no assessment boundary, and grade 5 (5-ESS1-2) says assessment does not include causes of seasons, so this is usually the first time students are asked for the cause.
The most common wrong idea, in study after study, is that summer comes when Earth is closer to the Sun. Many students who say "tilt" still mean the half that leans toward the Sun is closer. The app is built to test that idea with numbers, not to tell students the word.
The reasons for the seasons in one period
- Pick a town (before class) Open the app, press Find my town and pick yours (or the nearest town of 15,000 people or more). In Setup, fix the town for the class, then save the project and hand it out as the starter. Denver is the sample if you skip this.
- Predict (3 minutes) Everyone picks why summer is warmer: Earth is closer to the Sun, our half leans closer, the Sun is higher and up longer, or the axis flips toward the Sun. Nothing is marked right or wrong yet. Ask a few students to say why they picked theirs.
- Watch the shadow (7 minutes) Press Play. The shadow shrinks and swings until sun noon, when it is shortest and points north (south in the southern half of Earth). The app gives the clock time: in Denver in June it is 1:02 pm, not 12:00, because clocks are set for a whole time zone and daylight saving moves them an hour.
- Go to December (5 minutes) Press December solstice or drag the year graph. The Sun's path is lower and shorter, the day is about 9 hours 21 minutes in Denver against 15 in June, and the noon shadow is about twice as long as the stick. Ask: did Earth move farther from the Sun?
- The distance test (10 minutes) Open Tilt and Orbit and drag Earth to the day it is closest to the Sun. It is early January, about 147 million km, against about 152 million in early July: closest in the northern winter. Then pick Sydney: the same day, the same distance, and it is summer there.
- The closer half (5 minutes) The guide answers the "our half leans closer" idea with the town's own numbers: leaning brings Denver about 3,200 km nearer the Sun at a June noon than at a December noon, against a 5 million km change in Earth's distance through the year. What leaning changes is the angle: the same sunlight spread over about twice as much ground at a December noon.
- Predict again (5 minutes) Students answer the first question again. The sheet keeps both answers, with the first one on top, so you can see who started with distance, who with the closer half, and who changed.
- Talk it through (5 minutes) Ask the questions under How to tell whether it landed on the tools page. A student who can explain why January is closest and still winter has it.
Sunlight and a real shadow, a second period
The Sunlight chapter opens with its own prediction: how much more sunlight does a summer day get than a winter day here? Then three pictures: a beam of sunlight a meter wide landing on the ground and spreading out as the Sun gets lower; a day of sunlight on a square meter, today against the opposite solstice; and the size test. In Denver a summer day gets about 3.1 times the sunlight of a winter day, while Earth's changing distance changes sunlight by only about 7 percent.
Then go outside on a sunny day. A straight stick, flat ground and a tape measure: measure the stick and its shadow, from the foot of the stick to the middle of the fuzzy edge at the tip, and type both into Measure a real shadow with the time on the clock. The app works out the Sun's height from the shadow and compares it with its own; within 2 degrees counts as a match. Do it again a few weeks later and the shadow has changed.
What students get wrong, and where the app answers it
| What students say | Where the app answers it |
|---|---|
| Summer is when Earth is closer to the Sun | The distance box: closest in early January, in the northern winter. Sydney has summer at the same distance. The size test: about 3 times from the angle and day length against about 7 percent from distance. |
| The half that leans toward the Sun is closer | The guide's lean card: a few thousand km nearer, against 5 million km of change in Earth's distance. |
| The axis flips toward the Sun in summer | The axis arrow points the same way all year. The wrong axis switch shows what flipping would do: summer all year in the north. |
| The Sun is straight overhead at noon | The noon Sun's height on screen every day; in Denver it never gets above about 74 degrees. The Close-up shows the overhead spot staying between the tropics. |
| Australia has the same seasons we do | Pick Sydney: its day length runs opposite to Denver's on the year graph. |
| The equator has four seasons | Pick Quito: about 12 hours of daylight every day and a high noon Sun all year. The card says there are no big seasons. |
| The longest day is the hottest day | A card in the Sunlight chapter: the ground and oceans keep warming for weeks; most of the US is hottest in late July. |
| The shortest shadow is at 12:00 | Sun noon in Denver in June is 1:02 pm on the clock, and the app says why. |
What the app simplifies, on purpose
- Nothing in the space picture is to scale, and it says so: Earth is drawn thousands of times too big. The orbit is seen at a slant, so it looks oval; Orbit from above shows it is almost a perfect circle.
- The sunlight numbers are for the top of the air, before clouds and the air take any. Real ground gets less, and less still when the Sun is low, because its light crosses more air (a card at the high school level).
- Temperature is not modeled. One card explains why the hottest days come weeks after the longest day.
- Sunrise and sunset are for flat ground with no hills or buildings. Real times can differ by a minute or so.
- A southern summer day gets up to about 7 percent more sunlight than a northern one, because Earth is closest in January, but southern summers are about 5 days shorter, so both summers get the same sunlight in all. The app says this in a card, because students who notice the 7 percent often ask.
Middle school and high school
| Middle school | High school | |
|---|---|---|
| The Sun | Low, halfway up or high, with its angle in degrees; hours and minutes of daylight | Its height and direction in degrees, and the declination |
| Sunlight | How many times as much; about half, about three quarters of the beam | Watts per square meter, and sin of the Sun's height |
| Puzzles | Seven: the season from a picture, placing Earth, whose shadow, when is noon, midnight sun, no tilt, explain it | The same, plus finding a town's latitude from a shadow |
| Cards | The lag, the pole in June, the equinox, southern summer days | Also the air's effect and the tilt's slow 41,000 year swing |
The sheet, the puzzles and the setup
The Sheet in the app's header is the student's write-up: their first and last idea on top, a picture, their predictions before and after, their real shadow readings, the puzzles they did, and the questions. Hand in needs every question answered. Print gives a clean page.
Setup is for you: the level, which chapters students can open (Sun and Shadow is always on), whether the guide is on, one fixed town for the class, whether the tilt slider is on, the sheet's questions from a bank of eight, up to ten of your own, and a printed answer key with every puzzle's answer worked out by the model.
Standards
- MS-ESS1-1: a model of the Earth-sun-moon system to describe the cyclic pattern of seasons, with the evidence statement's predictions (the season from the positions and a place; the positions from a season and a place) and its scale limits.
- ESS1.B: Earth's spin axis is fixed in direction over the short term but tilted relative to its orbit around the Sun; the seasons are a result of that tilt and are caused by the differential intensity of sunlight on different areas of Earth across the year.
- Texas TEKS 6.9(A): model and illustrate how the tilted Earth revolves around the Sun, causing changes in seasons.
- 5-ESS1-2 (with Setup turning off the cause): daily changes in the length and direction of shadows, and day and night.
- HS-ESS2-4, one card: the tilt's slow change over about 41,000 years.
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Page last reviewed November 2026.
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