NearLight

New: A more realistic night sky with a true telescope mode, Bortle simulation, seeing, and Messier objects. Save the date: August 12, 2026 — total solar eclipse!

NearLight is a 3D space simulator for exploring nearby star systems, visualising interstellar distances in our galaxy and calculating travel times using both classical and relativistic physics. Explore massive black holes, fly through a living star map, inspect real stars and see how space travel changes when the Lorentz factor and relativity come into play.

Calculate time dilation and see its effects visually.

Is your favourite sci-fi film physically accurate?

Built for astronomy fans, sci-fi lovers and physics enthusiasts, NearLight turns nearby space into an interactive experience. Search star systems, inspect stellar data and exoplanets, compare travel times across different speed and acceleration models, and see the relativistic effects of black holes with your own eyes.

From our Solar System, represented with accurate orbital data, to realistic star maps and journeys through the Milky Way with relativistic calculations, NearLight makes space travel feel tangible.

Calculate acceleration and deceleration with different g values, including coast phases, and see where your spacecraft has to turn. Get relativistic onboard travel times quickly with just a slider. Find out how much time has passed on Earth.

Features:

• Tour our Solar System in a Kepler-accurate 3D scene: the Sun, all 8 planets and 8 major moons, with a day/night Earth, Saturn's rings and a textured sky.
• Full observatory in Telescope Mode with 8 eyepieces and realistic atmospheric seeing.
• Explore 1,000 light-years of nearby star systems in a cinematic 3D space view.
• Search and inspect 8,000+ real stars, including known names, distances and stellar data.
• Discover red-highlighted neighbouring stars within 10 light-years of your selected destination.
• Plan trips through the Milky Way and see the real travel time and distance.
• Switch between three onboard cameras during a trip: free view, side chase cam and locked first-person cockpit view.
• Experience relativistic optics from the cockpit near light speed: stellar aberration, the forward "headlight" cone, Doppler colour shift and relativistic beaming.
• Explore over 70 detailed known black holes, including the massive TON 618 and Gargantua from Interstellar.
• Compare Earth travel time with onboard travel time using relativistic calculations.
• View the full relativistic picture: Earth distance, length-contracted distance, peak speed as a fraction of c and the estimated energy required. Switch units between joules, TWh, PWh and "Sun-output time".
• Navigate with 6 degrees of freedom: rotate the map, pinch to zoom, and move the axis in all directions with two fingers.
• Reset your view back to your target, turn labels on or off, or enable Auto Rotation around your selected object.
• Switch between constant-speed and constant-acceleration space travel models.
• In Constant c mode, define an instant and constant travel speed as a fraction of light speed.
• In Constant g mode, set g values for acceleration and deceleration phases to simulate a real spacecraft.
• Classical Spaceflight calculates journeys through the Solar System with a departure burn, real-time transfer arc, flip manoeuvre and capture burn into orbit at the destination.
• Simulate approaching the event horizon, change the spin of the black hole disc and watch two different clocks run at different rates.
• See the effects of time dilation, the Lorentz factor and near-light-speed travel, where weeks, months or even years pass faster on Earth than on your ship.
• View exoplanet host stars and relevant stellar metadata.
• Turn on ambient space music, relax and watch the universe unfold.

NearLight currently has an English app interface and runs natively on Mac, iPad and iPhone — fully offline, with no account and no tracking.