🕹️ How to play

• 🚀 Flyby missions: the Sun pulls you faster. Tap FLYBY when the ring around a planet turns green. Hold BRAKE to use the blue engines (it uses fuel).
• The pink dot on the speed gauge shows your speed when you reach Mercury. Get it into the green, and Mercury catches you!
• 🛰️ Orbit missions: hold ▲ Up or ▼ Down. Fly over a glowing spot, below its yellow line, and tap 📷 SNAP!
• Low over the sunny side gets too hot. Fly high there, and low on the cold night side.

Keyboard: Space = FLYBY / SNAP, ↓ or B = BRAKE, ↑ ↓ = up and down in orbit.

🔬 Is it real?

Falling toward the Sun really makes a spacecraft faster, so going into orbit around Mercury needs lots of braking. BepiColombo really used gentle ion engines and 9 flybys of Earth, Venus and Mercury, and its engines really lost power in 2024. Bepi's orbit really goes over Mercury's poles, Mio really separates and flies a bigger orbit, and there may really be ice in dark polar craters.

Game note: everything is much faster and closer together than real, the planets wait for you on their orbits, and the speeds are pretend numbers. Real flybys can speed a spacecraft up or slow it down; here they always help you slow down. Bepi and Mio's faces are pretend.

🪐 Read the story

Why does it take 8 years to reach the closest planet to the Sun? Read Bepi and Mio's Long Trip to Mercury first.