Exploring Our Solar System
Like Duolingo, but for Exploring Our Solar System. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
For the part of you with thirty open tabs that never became anything.
Free during early access · No credit card · iPhone & Android

Key ideas in Exploring Our Solar System
- The Sun contains over 99% of the solar system's mass
- Solar radiation provides the thermal energy for weather
- Massive objects exert the gravitational pull necessary to keep planets in orbit
- Plants require solar light for energy production
- Planets would fly off in straight lines without solar gravity
- Solar intensity decreases as distance from the Sun increases
- The Sun's mass makes it the center
- Temperatures would drop to near absolute zero without solar heat
- Distance determines the amount of light and heat a planet receives
- How solar energy drives specific planetary processes
- The Sun is the source of nearly all energy in the solar system
- Why the Sun's mass makes it the center of the solar system
- Solar energy is the 'engine' for planetary systems
- The consequences of the Sun disappearing from the solar system
- The relationship between distance from the Sun and planetary temperature
- Gravitational pull increases as mass increases
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 Exploring Our Solar System 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.
If we put everything in space on a giant scale, which object would take up almost the whole side?
Get it right to open this lesson and 53 more in the app.
Where Exploring Our Solar System takes you
Take a trip through space to meet our sun and the planets that circle it. Learn what makes each world special and how we explore the stars from Earth.
- 1
Our Neighborhood in Space
- The Sun: Our Big Bright Star
- Gravity: The Invisible Glue
- Orbits and How Planets Move
- The Order of the Planets
- 2
The Inner Rocky Worlds
- Mercury: The Small Hot Planet
- Venus: The Brightest Neighbor
- Earth: Our Perfect Home
- The Moon: Earth's Best Friend
- Mars: The Dusty Red Planet
- The Asteroid Belt
- 3
The Giant Outer Planets
- Jupiter: The King of Planets
- Saturn: The One with Rings
- Uranus and Neptune: The Ice Giants
- 4
Beyond the Big Planets
- Pluto and the Dwarf Planets
- Comets: Snowy Space Rocks
- The Edge of Our System
- How We Use Telescopes
- Sending Robots to Space
4 sections · 18 units · 54 levels. Built to play, not to enroll.
You pick the voice
Exploring Our Solar System is taught in the Explain Like I'm 5 style: no big words. promise.. 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.
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Start Exploring Our Solar System today.
Download Tomo, search Exploring Our Solar System, and play your first lesson in under a minute.