What started as a small project to gain experience with Vibe coding has now grown into a small astrophysics simulator! Version 0.3 is on its way to the Microsoft Store and should be available there early next week.

I’ve primarily improved the graphics, but I’ve also added many new features.

Native Physics Engine
The biggest step under the hood: The entire gravity simulation now runs in a native C library with AVX2 vectorization. This enables significantly faster simulation speeds and opens the door to more sophisticated integration methods. Five backends are now available—from simple Euler to Barnes’ hat tree and a Hermite 4 integrator for high accuracy.

More Realistic Graphics
Planets and stars are now rendered with radial luminosity gradients, and stars have their own surface textures. Comets leave behind visible ion and dust tails, dynamically composed of thousands of particles.

Collisions and Fragmentation
Bodies can not only merge—at high relative velocities, they shatter into fragments. The native collision module calculates tidal forces and distributes mass and momentum to the debris with physical accuracy.

Date-Accurate Planetary Orbits
All eight planets and eleven moons are initialized to the current date using JPL Kepler elements—the starting configuration thus corresponds to the real solar system.

Trajectory Preview & Adding Bodies
When placing a new body, the simulation immediately displays a dashed preview of the expected trajectory. Mass, radius, color, and five presets (from asteroid to gas giant) are freely selectable.

Simulation Snapshots
Interesting constellations can now be saved, loaded, and named—so no more beautiful random situations are lost.