We've changed our name — alarm-clock.org is now timeandspace.science. Same tools, same pages, new address.

Lesson Plans, by Topic and Grade

Timed lessons a teacher can run tomorrow, on tools that need no sign-up and no install. Every step is a link that opens the exact view — place, date, zoom and speed ride in the address, so one link puts the projector and thirty student screens on the same sky. The tools themselves are on the classroom page.

Start from the question a student actually asked

Every class has them — the questions that sound simple and aren't. Why does the moon light up differently through the month? Why don't the planets get sucked into the sun? Why does Mercury travel faster than Mars? Each of those is a lesson here, and the answer is never recited — the class watches the real motions until the rule shows itself.

Some take a measurement to answer: why does the moon rise about fifty minutes later every night? Is today longer than yesterday — and by how much? Some hide a broken model that has to be caught: if the sun, Earth and moon line up every month, why isn't there an eclipse every month? Is it summer because we're closer to the sun — and if so, why is it winter in Sydney on the same day? And one is a deadline dressed as geometry: why can a rocket to Mars only launch every 26 months?

And some questions turn out to be about numbers wearing a costume: why does February grow a day every four years — and who decided? How old is the sunlight hitting your desk, and how can a year measure a distance? And how does one machine — the Earth, the moon and the sun — keep the day, the month and the year all ticking at once? Those lessons are where space stops being a picture and starts being arithmetic.

Pick the question, and the grade band comes with it — or browse the grid below.

The solar system and gravity

Why does everything out there orbit — and why don't the planets fall into the sun?

Grades K–2The planet race — 20 min · observe it

Grades 3–4The solar system, gravity and moons — 45 min · describe the pattern

Grades 5–6Bigger orbit, longer year — find the rule — 45 min · measure it

Grades 7–8Gravity runs the moons too — and your weight — 45 min · explain the mechanism

High school & upLaunch windows: aim where it will be — 50 min · quantify it — and question the model

The moon and its phases

Why does the moon light up differently through the month?

Grades K–2Draw tonight's moon, then go and check — 20 min · observe it

Grades 3–4The moon goes around — watch the light follow — 35 min · describe the pattern

Grades 5–6The 50-minute slip — measure it — 40 min · measure it

Grades 7–8Why isn't there an eclipse every month? — 45 min · explain the mechanism

High school & upTwo months — and who decides what a supermoon is? — 50 min · quantify it — and question the model

The seasons and the length of a day

Why is it summer here and winter in Sydney — on the same day?

Grades K–2Is today longer than yesterday? — 20 min · observe it

Grades 3–4Three towns, three stories — 35 min · describe the pattern

Grades 5–6Measure what the tilt does — 45 min · measure it

Grades 7–8Summer is tilt, not distance — 45 min · explain the mechanism

High school & upPut numbers on the sun's height — 50 min · quantify it — and question the model

The Earth, moon and sun as one machine

The day, the month and the year — how does one machine keep all three clocks?

Grades K–2coming — ask for this band and it moves up the list

Grades 3–4coming — ask for this band and it moves up the list

Grades 5–6One machine, three clocks: the day, the month and the year — 45 min · measure it

Grades 7–8coming — ask for this band and it moves up the list

High school & upcoming — ask for this band and it moves up the list

Leap years and the calendar

Why does February grow a day every four years — and who decided?

Grades K–2coming — ask for this band and it moves up the list

Grades 3–4coming — ask for this band and it moves up the list

Grades 5–6The leap year: a fraction with consequences — 45 min · measure it

Grades 7–8coming — ask for this band and it moves up the list

High school & upcoming — ask for this band and it moves up the list

The speed of light and the light year

How old is the sunlight hitting your desk — and how can a year measure a distance?

Grades K–2coming — ask for this band and it moves up the list

Grades 3–4coming — ask for this band and it moves up the list

Grades 5–6coming — ask for this band and it moves up the list

Grades 7–8Eight minutes old: light, and distance measured in time — 45 min · explain the mechanism

High school & upcoming — ask for this band and it moves up the list

Students teach the class — the five-minute lesson

Some of the best lessons here will be taught by a nine-year-old. Letting a student teach five minutes does three things at once: it builds comfort in front of a room, it forces the deep version of learning (you cannot teach what you only half know), and it hands them the rarest thing in a school week — the choice of what to study. Frame it exactly that way: pick anything you're curious about, inside science and space, and share it.

Three ways to pick a topic

Take a ready-made five minutes: every step of every plan above carries its own minutes — hand a student one step, link and all, and it is already a lesson with a beginning and an end.
Pick from the list below: each one opens the exact view, so the "slides" are the live sky.
Bring your own: anything inside space and science counts, subject to the teacher's yes.

5 minThe planet race — who laps whom, and why the winner is the innermost

5 minSaturn's rings and moons — what the rings are, and Titan

5 minThe moon's phases in one picture — the angle rule: new beside the sun, full opposite

5 minWhy the moon rises 50 minutes later each night — one table, one subtraction, one orbit

5 minThe midnight sun — a day that never ends, live from Anchorage

5 minWhy no eclipse every month — the 5° tilt that saves the full moon

5 minThe Earth and Moon to true scale — the emptiness nobody's poster shows

5 minWhat you'd weigh on Saturn — 95 Earths of planet, one Earth of gravity

5 minThe asteroid belt — where it is, what's in it, why it's no danger to fly through

5 minLaunch windows to Mars — why rockets wait 26 months for a green light

5 minThe "dark side" of the moon — tidal locking, and why the far side isn't dark

5 minWhat a supermoon actually is — and who gets to decide — the threshold is on the page

5 minWhy Mars rovers drive themselves — radio takes 3 to 22 minutes each way — no joystick crosses that

5 minThe year is not a whole number — 365.2422 days, and everything the calendar does about it

Using AI to build your five minutes — the honest way

An AI assistant is genuinely good at turning a topic into a five-minute plan — if you feed it the right ingredients and check what comes back. The recipe:

Tell it exactly who and what: “I'm a 5th grader teaching my class a 5-minute lesson about why the moon rises later each night. Build me: a one-sentence hook question, two minutes of showing using this link, one surprising fact, and one question to ask the class at the end.”
Paste the link you'll project (any lesson step or list entry above) so the plan is built around what the class will actually see.
Verify every fact before you say it — against this site or NASA. If the AI said it and you can't find it anywhere else, it doesn't go in your lesson. That rule is not a formality; it is the lesson behind the lesson.
The AI writes the plan; you do the learning. If you can answer one unexpected question from the class, you learned it. If you only read it aloud, you didn't.
Show the teacher first. Every performer has an editor.

Coming next — help us pick

Four more topics are planned, each on tools the site already has. The feedback form below is the vote:

Day and night — the Earth's turn, the terminator line, and who on the world map is asleep right now.
How big and how empty space is — the to-scale Earth and Moon, the corridor scale model, and the peppercorn walk.
Measuring time itself — the one-minute calibration game, repeated trials, and how far a browser timer can be trusted.
Tides — the sun–moon angle over a month beside a real NOAA station's predictions (US coastal classes).

Teachers: make these lessons better

You are the one standing in front of the class, so you will see what we cannot: a task that runs long, a question that lands better another way, a grade level pitched wrong, a topic we should build next. Tell us — improvements go into the page, and if we use yours, your class gets the credit on it, the same promise the classroom request form makes.

Lesson plan FAQ

Do the lesson links work on any school computer? Yes — everything runs in the browser with nothing installed and no sign-up. Each link carries the whole view (place, date, zoom, speed) in the address, so the same link puts the projector and every student machine on the same screen.

Are the simulators real, or animations? The positions are computed from the real orbits when the page loads — the same standard methods observatories teach from — and every page says exactly what the drawing exaggerates. The one honest exception: where a moon sits along its orbit is illustrative, and the simulator says so on the page.

How are the grade bands different? Every band re-asks the same driving question one level deeper: K–2 observe it, 3–4 describe the pattern, 5–6 measure it, 7–8 explain the mechanism, high school quantifies it and questions the model itself.

Can students use these without a teacher? Yes — every lesson lists questions to chase alone, every step is time-boxed so one step can become a student's own five-minute lesson, and the tools work as well at a kitchen table as on a projector.

Can I print or adapt the plans? Yes — free to use, adapt and share for teaching. Each page has a feedback form at the bottom; improvements that get used credit your class on the page.

💡 Question, problem or idea? Tell us →