Stars, Planets, and the Cosmic Void
Journey from the familiar glow of our Moon to the crushing gravity of black holes. Master the life cycles of stars and discover the strange worlds orbiting distant suns.
Like Duolingo, but for Stars, Planets, and the Cosmic Void. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
77 levels across 8 sections, about 154 minutes end to end, roughly 31 days at five minutes a day. It moves through Our Local Wonders, The Secret Life of Stars, The End of the Road, The Gravity Extremes, Worlds Beyond Our Sun, Visitors from the Deep, Reading the Night Sky, and The Big Picture. It starts from scratch.
Free forever · No credit card · iPhone & Android
Key ideas in Stars, Planets, and the Cosmic Void
- The Moon's source of light
- The effect of tidal locking on our view of the Moon
- Half of the Moon is always lit by the Sun regardless of its phase
- Phases change based on how much of that lit half is angled toward Earth
- A Full Moon occurs when the entire sunlit side faces us
- Eclipses only happen when the Sun, Earth, and Moon form a straight line
- A solar eclipse blocks the Sun from our view
- A lunar eclipse involves the Moon falling into Earth's shadow
- The progression of Moon phases based on sunlit perspective
- Distinguishing between solar and lunar eclipse alignments
- The Moon's gravitational pull 'tugs' on Earth's water
- Tides rise and fall as different parts of Earth rotate under the Moon's pull
- The Moon is the primary cause of high and low tides
- The Moon's influence on Earth's oceans
- Moons formed from local debris disks follow stable, circular paths
- Jupiter's massive gravity pulls and squeezes Io's interior
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives Stars, Planets, and the Cosmic Void the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
How does the Moon's rotation speed compare to the time it takes to complete one orbit around Earth?
Get it right to open this lesson and 76 more in the app.
How to learn Stars, Planets, and the Cosmic Void, step by step
Go in order. 77 short levels across 8 sections, about 2 hours 34 minutes in all, five minutes a day.
- 1
Our Local Wonders
- The Moon and its Secrets
- Moons of the Solar System
- 2
The Secret Life of Stars
- Stellar Nurseries
- The Main Sequence
- Stellar Classification
- 3
The End of the Road
- Red Giants and White Dwarfs
- Supernovae: The Great Explosion
- Neutron Stars and Pulsars
- 4
The Gravity Extremes
- Black Holes: The Point of No Return
- Time and Space Near a Black Hole
- White Holes and Wormholes
- 5
Worlds Beyond Our Sun
- Hunting for Exoplanets
- Strange New Worlds
- The Search for Life
- 6
Visitors from the Deep
- Comets: The Dirty Snowballs
- Asteroids and Meteors
- 7
Reading the Night Sky
- Constellations and Navigation
- Measuring the Universe
- 8
The Big Picture
- The Milky Way and Beyond
- Dark Matter and Dark Energy
8 sections · 20 units · 77 levels. Built to play, not to enroll.
Questions about Stars, Planets, and the Cosmic Void
How do I learn Stars, Planets, and the Cosmic Void?
Go in order: start with Our Local Wonders, then The Secret Life of Stars, then The End of the Road, then The Gravity Extremes, and 4 more sections after that. On Tomo that's 77 short levels, about 2 hours 34 minutes in all, played five minutes a day. Start free and play the first level in under a minute.
Is there a Duolingo-style app for Stars, Planets, and the Cosmic Void?
Yes. Tomo works like Duolingo: short daily lessons, streaks and quick quizzes. Stars, Planets, and the Cosmic Void is one of its free courses, and you can type any other topic to get a course of your own.
Is the Stars, Planets, and the Cosmic Void course free?
Yes. Stars, Planets, and the Cosmic Void is playable on Tomo's free plan, which doesn't expire. No credit card, no waitlist. Download the app and start your first lesson.
How long does it take to learn Stars, Planets, and the Cosmic Void?
77 levels across 8 sections, about 2 hours 34 minutes of play in total. It's built for five minutes a day, so you finish it a little at a time instead of all at once.
Do I need any background to start Stars, Planets, and the Cosmic Void?
No. It's pitched at a beginner level, so it starts where you are and builds up. If you can tap a phone, you can start.
Tomo is in ChatGPT
Tomo is also a ChatGPT plugin: the same playable courses, built and played inside your chat.
Add Tomo to ChatGPT- What to ask
- “Make me a Tomo course on black holes.” “Turn this chat into a Tomo course.”
- What you get
- Quick questions with instant feedback, hearts and stars, ready to play in about a minute.
- Where it goes
- No sign-up to start. Connect your Tomo account and your streak carries on in the app.
You pick the voice
Stars, Planets, and the Cosmic Void is taught in the Professor style: clear, structured, thorough. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
More Science on Tomo
The Night Sky and Beyond
Journey from your backyard to the edge of the observable universe. Learn to navigate the constellations, understand the lives of stars, and explore the mysteries of black holes and dark energy.
The Universe Above Us
Journey from your own backyard to the edge of the observable universe. Discover how stars are born, why time slows down near black holes, and how we are searching for life among the billions of galaxies.
Astronomy: Reading the Night Sky
Learn to read the sky like an astronomer, from locating planets with the naked eye to decoding the lifecycles of stars and distant galaxies. This course equips you with a solid working knowledge of how our solar system moves, how cosmic matter evolves, and how light reveals the shape of our expanding universe.
Navigating the Cosmos
Move beyond the names of planets and dive into the mechanics of space travel, the life cycles of stars, and the strange behavior of time and gravity in the deep universe.
The Cosmos and Beyond
Go beyond the basics of the solar system to master the mechanics of orbital motion, stellar evolution, and the deep-space structures that define our universe.
Astrophysics and the Cosmos
Move beyond basic stargazing to understand the physical laws governing the birth of stars, the warping of spacetime, and the ultimate fate of the universe.
Start Stars, Planets, and the Cosmic Void today.
Download Tomo, search Stars, Planets, and the Cosmic Void, and play your first lesson in under a minute.