Rubies on Mars?
Why it matters
Gem minerals like corundum only form under specific high-temperature conditions, so finding them on Mars helps decode how rocky planets forge and reshape their crusts.
Ask or build with AIDescribe a world and it gets built, or name a real exoplanet. You can also ask about a planet once you have one open.
TerraForge: build your own planet online
Forge a world. Build a system. Share the galaxy.Every world simulated on a real physics engine.
New here? Read the guideWorlds forgedplanets built by the community — and counting
Planet of the Week
Every week we spotlight the most intriguing world the community has forged. Think you can build something rarer, stranger, more alive? Create your planet — the most unique one could be featured next.
A Ringed Ocean World Basking Beside a Blazing O-Star
Keplar - 1239 e3.453a b.c.a (aka Badpun)Earth Like
98 / 100Habitability
301 KO-type blue giant301.2 AURing systemLife possible
A living, ocean-blue super-Earth 4.8 times our planet's mass, wrapped in broad bright rings. It orbits 301 AU from a scorching O-type star — far enough that the glare mellows to a comfortable 301 K, giving it a 98% habitability score.Build with AI
Say what you want. The physics does the rest.
Describe a world in plain language and the assistant sets its elements, orbit, star and spin — then checks the result against the same simulation that runs everything else here. Ask it about a planet and it answers from that world’s own numbers. It can also build any of 5,900 real exoplanetsstraight from astronomers’ measurements.
The real ones
5,900 real exoplanets, run through our physics
Every confirmed planet astronomers have measured well enough to build — its real mass, orbit and star, fed into the same simulation that runs everything else here. It decides what each one becomes. 10 come out Earth-like.
Earth Like10 planets
Rocky Terrestrial458 planets
Ice World15 planets
Water-Rich4 planets
Gas Giant2,155 planets
Sub-Neptune2,239 planets
Lava World550 planets
Ice Giant237 planets
Brown Dwarf218 planets
Barren14 planets
In the news
Build a Rocky
Mars' Molten Heart is Long Gone, but Some Magma Chambers May Persist
Why it matters
If Mars still harbors active magma chambers, the 'dead' planet isn't fully cold inside — reshaping how we think rocky planets cool and stay geologically alive over billions of years.
New simulations watch a young Jupiter-mass planet grow by gobbling disk gas
Why it matters
Watching a simulated gas giant feed and drift shows why Jupiter-like planets end up where they do — and why some spiral inward to become scorching 'hot Jupiters.'
Rocky exoplanets are built from the same stuff as their stars — and lose volatiles like Earth did
Why it matters
If rocky worlds shed their lightest elements the same way Earth did, then Earth's recipe may be the galaxy's default — encouraging news for finding more planets like home.
Proxima b: a closer look at the nearest exoplanet to Earth
Why it matters
The nearest exoplanet sits just four light-years away, circling our closest stellar neighbor inside its habitable zone — the very first place we'd look for life beyond the Solar System.
Further reading
How these worlds are found, what the measurements honestly tell us, and what might live on them.
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New here
How to use TerraForge
A short guide for a first visit. It covers what you can build, what every button on the scene does, and what happens to a world once you save it. No prior experience with space or 3D software needed.
Building your first planet
Elements, star, orbit and moons — and what the six-second formation is showing you.
What the icons do
The globe, the orrery, the mountains, the magnet and the camera, one by one.
Saving and sharing
You get a link without signing in. Here is what an account changes.
Star systems
Put your worlds around one star, and let orbital physics decide what fits.