Universe Sandbox 36.3.3 — Mac version

Dropping a thousand moons onto Jupiter

Tinkerers, space nerds, and anyone who ever wondered what would happen if you dropped a thousand moons onto Jupiter. It's not a game with levels or scores. You open the sandbox, add a few objects, and let things get messy.

What you do, step by step

1. Pick a starting point. Open a simulation like Earth and Moon, or start with an empty scene. The included exosatellite sim is a nice new toy to poke at.
2. Add or duplicate objects. Drop in a star, duplicate the Earth a dozen times, or spawn a black hole. Version 36 added a simple duplicate command which saves a lot of clicking.
3. Hit play. Gravity does the work. Orbits wobble, things collide, and the climate layer on rocky planets shifts in real time. Craters now form and merge in ways that look properly smashed together.
4. Poke things mid-flight. Fling an asteroid into a gas giant. Watch the atmosphere react. Crank up the mass of the Sun just to see the inner planets fry. Black holes even evaporate over time if you leave them alone.

The desktop version pairs with a VR mode if you have a headset, but it's completely at home on a Mac screen. You can spend ten minutes or an entire evening. There's no wrong way to muck about with a galaxy.

Follow a comet from its own orbit

Some of the best bits aren't obvious at first. Right-click any object and pick Follow — the camera locks on and rides along, which makes watching a comet's orbit far more dramatic. The Stabilize button in an object's orbit panel is a quick fix when your moons start wobbling off into deep space.

Holding Shift while adding an object drops it exactly at your camera's position. Useful for lining up a rogue planet right where you're looking instead of fiddling with coordinates. If your system gets too chaotic, tap Space to pause, then use the Undo arrow in the toolbar — it steps back one physics tick at a time.

The climate layer on rocky worlds updates in real time, but you can also toggle it with Ctrl+L to compare surface details underneath. A small thing, but handy when you're nudging a planet closer to its star to see where the oceans boil off.

Build a collision from scratch

You've got a black hole that evaporates — that's the new toy in 36.3.3. Here's a quick workflow to set up a proper smash-up.

1. Empty the scene. Open the menu, pick New, and choose Empty. No distractions.
2. Spawn a star. Add a Sun-mass star near the centre. Give it a name so you can find it later.
3. Dupe an Earth. Add one rocky planet, then use the duplicate command to make three or four copies, each nudged a few degrees off the last. They'll start too close — that's the point.
4. Add your black hole. Drop one in at the edge of the clump with a gentle nudge toward the star. Hit play and let gravity sort out the traffic jam. Craters stack and merge, orbits cross, and the black hole slowly evaporates as the chaos unfolds.

It's a five-minute setup that unfolds for half an hour. Save the sim halfway through — you'll want to replay the best collisions.

• Collision craters form and combine together more realistically
• Objects can be duplicated
• Black holes evaporate
• Simulation of a newly discovered exosatellite included
• Apple Silicon support only — Intel Macs no longer supported
• Requires macOS 11.0 or later

• macOS 11.0 or later
• Apple Silicon (M1 or newer)
• Metal graphics support