Explore a universe
you can fly through.

Help with Cosmic Journey Into Space for iPhone and iPad.

Start where you are

Tap Use my location to place your departure on Earth. Location access is optional: Choose on map lets you tap a launch site or enter its latitude and longitude. The app remembers your last launch site on your device, so next time it opens on your launch pad. The sky above you is drawn for this moment: blue by day, stars coming out through twilight, the Moon in its real phase. The strip Above you right now lists the planets and bright stars that are up; tap one to turn and face it.

Choose something and go

Point your phone at the sky, or drag to look around. Keep a landmark inside the circle for about a second, or tap it, and it is chosen; then press Go. The choice stays until you clear it or choose something else. Bright landmarks are offered as you look around; faint ones only when you look straight at them. You can turn this off under aim assist in the three-dot menu.

Or tap Choose a body to search more than 400,000 offline destinations by name or catalogue number: stars, 6,344 exoplanets, 53,914 galaxies and the Solar System. Select 200 field guides for featured objects. Try Moon, Saturn, Sirius, TRAPPIST-1 e or Messier 87. If what you chose is below your horizon, the flight sets off from the side of Earth that faces it, and a notice says so. To fly with no destination, tap Aim straight up or look where you like and tap Launch.

In flight

Every flight is a straight line. The app sets the pace so that a flight takes seconds: about six to the Moon, never more than fourteen to a chosen destination. Lift-off and arrival are gentle and the middle is as fast as it needs to be, so the speed shown can be millions of light-years a second. Travelling faster than light is fiction, and the screen says so while you do it.

The flight screen shows one line of progress and Pause. A line at the top names real distances as you pass them; all of them are kept in your journey log. The button beside Pause opens the other controls: a fixed speed for that one flight, Look back, Face course, Choose a body, What is near and Finish. Looking around never changes your course. Pause and Keep flying stop and resume the same journey. Backgrounding pauses flight. The globe button returns you to your original launch site.

The first catalog body on your path stops the flight, even if you chose a destination farther away. Most directions miss everything in the catalog, so an open flight can carry on to the observable horizon unless you pause.

When you arrive

A chosen destination stops with the whole object in view. Where next? opens the destination list, and a suggestion below it offers the nearest landmark from where you are. Look back faces where you came from, and a line says how old the light from home is where you are. Galaxies, nebulae and clusters are regions rather than solid surfaces; Fly through carries on into them.

Find it in your own sky

On arrival, a line says where that place is in the real sky over your launch site at that moment: how high it is and in which direction, whether you could see it with your own eyes, with binoculars or only with a telescope, whether daylight is hiding it and where it will be once the sky is dark, or how long until it rises. If it is above the horizon, See it stands you back on the ground facing it, with it chosen.

This is worked out on your device for the time on its clock. It cannot know about cloud, hills, buildings or city lights, and rising times are good to a few minutes. If you picked your launch site on the map, it describes the sky over that site, not the sky where you are.

Finish and see your route

Tap Finish, on arrival or in the three-dot menu, to see where you flew. The map is to scale: straight flights are straight lines, and the bar is the real length it says. Flights can differ in length by a factor of trillions, so the map opens on the first flight and pulls back through each in turn. A route through space is not flat, so the map looks straight down on each flight as it shows it. Drag to move the map, pinch to zoom, twist to turn it, or tap a stop in the list to see its flight. Journey log, in the three-dot menu, lists the places you have reached and the distances you have passed.

Speed streaks and cosmic scale

Streaks at speed are a film convention, not something a traveller would see, so they are off unless you switch them on in the three-dot menu. They stop when paused and respect the device’s Reduce Motion setting.

The menu’s Observable-universe horizon option offers a journey to about 46 billion light-years from Earth, which takes about twenty seconds. It still stops if a mapped body lies on the course. This horizon represents a present-day observable scale, not a wall or the end of space. The full universe may extend farther; its total size is unknown. Expansion and a cosmological light cone are not simulated. Read NASA’s explanation.

Plan your departure time

Tap the sky clock to pause time, change its speed, or choose a date between 1900 and 2100. A flight captures the sky at departure: positions stay fixed during travel so the course remains straight. Departure sky identifies this state. Changing time starts a new course plan.

If phone aiming is unavailable

True-north sky alignment from your own location needs optional location access, a compass and device motion. Phone look in flight or at a manually chosen launch site uses relative motion and does not require location access. Move the phone gently if calibration is requested, and avoid magnetic interference. Drag to aim if sensors are unavailable or access is denied. The modeled horizon is a spherical Earth surface with an atmosphere, without buildings or local terrain.

Find more objects

The bundled HYG, Gaia DR3, exoplanet and galaxy catalogs work offline. The Gaia data is a quality-filtered nearby sample; no single complete database of every celestial body is included. For other Solar System objects, enter a name and choose the NASA lookup. Use SIMBAD lookup for distant objects with a usable catalog distance. An internet connection is required for these lookups. If a name is ambiguous, choose a matching result or try a catalog identifier.

Downloaded NASA trajectories cover a limited time window. The app pauses at that boundary; refresh the trajectory for the date you want to explore. If a service is unavailable, try again later or choose a bundled destination.

How accurate is the universe?

Planet and Moon positions are calculated for the selected time. Stars use measured catalog positions and available space motion, and galaxies their catalogued distances. Earth, the Moon, Mercury, Mars, Jupiter, Saturn and Neptune use maps made from spacecraft images, turned the way they really face and lit from the Sun’s real direction; nothing is drawn larger than it is. Exoplanet orbits use catalog periods and separations when available; their phase, orientation and appearance are illustrative, as are star surfaces, fine ring detail and the shapes of most galaxies. The colours of the sky from the ground are a display model. This is an educational simulation, and faster-than-light travel is a viewing tool.

Open Destination details and About this universe for sources and modeling limits.

Find the original guided journeys

Open the three-dot menu, then choose Guided journeys. Both the launch experience and guided journeys can use optional location access to calculate your local sky. Manual launch-site selection works without it.

If something stops responding

Return to Earth using the globe button, or close and reopen the app. For a lookup problem, check your connection and try the object’s exact catalog name. Include your device model, iOS version, app version, destination and steps when reporting a problem.

Contact support

For help with Cosmic Journey or questions about your privacy, email 34_chess_claques@icloud.com. Include your device model, iOS version, app version and a description of the problem. Please do not send passwords or precise personal location details.