A universe explorer built from real astronomical data.
Travel from the solar system to nearby stars, deep-sky objects and the observed cosmic web. Space Time brings astronomical catalogs, telescope surveys and computed motion into one navigable view.
Orion Nebula
real survey imagery · navigable in 3D
2.5 millionmapped stars
32,000+deep-sky objects
9,000+tracked satellites
630,000+DESI galaxies
Search for an object, go there, and keep moving.
What Space Time does now
Move through every scale in the same view.
Distance determines which objects become visible. The same controls, selection and time system remain available from planets to large-scale structure.
Continuous scale
From the solar system to large-scale structure
Planets give way to nearby stars, the Milky Way, galaxy clusters and the observed cosmic web as the camera moves outward.
Sky cultures
The same stars, drawn by twenty-five cultures
Swap the constellation figures, names and stories to Boorong, Inca, Māori, Hawaiian, Chinese and more. Dark-cloud figures like the Emu are drawn in the Milky Way dust, and every culture shows its authors, source and license.
What comes next
Countdowns to the next big sky moments
The next lunar and solar eclipses, the Apophis 2029 flyby and the nearest meteor peak and opposition, with who on Earth can see each one, where the date comes from, and an email reminder before it happens.
Resolved destinations
Observed structure replaces anonymous glow
Andromeda includes 2,753 Hubble PHAT cluster positions. The Coma Cluster resolves into named catalog galaxies, while stellar clusters use measured Gaia members.
A moving star catalog
Stars change position when the clock moves
Measured Gaia and HYG proper motion moves 411,954 stars through the same three-dimensional scene. Radial velocity is included only for stars with a catalog measurement.
Catalog galaxies at physical distance
Go to galaxies beyond the curated landmarks
Catalog galaxies with usable redshift data now become physical destinations. Direction, distance, dimensions, position angle and morphology come from the catalog; generic close-range structure is identified as a reconstruction.
Dated observations
See which atmosphere was actually observed
Jupiter, Saturn, Uranus and Neptune can use archived Hubble OPAL maps. The observation epoch and filters are shown; the app does not pretend an old image is a live forecast.
Three-dimensional evidence
Enter a reconstructed supernova remnant
Cassiopeia A, the Crab Nebula and SN 1987A are physical destinations built from published three-dimensional evidence, with analytical context identified separately.
Survey imagery
Open real observations in context
DSS2, HiPS and selected observatory images are placed at their catalog coordinates. Open an observation, identify its target and continue moving through the scene.
Surface view
View the sky from other worlds
Land on a planet or moon, change the time and select objects in the local sky. Return to space without losing your place.
Relativistic travel
Compare the clocks during a journey
Choose a destination and see the travel time, the time elapsed at the departure point and the time experienced by the traveler. The calculation and its assumptions are shown.
Galaxy environments
Identify galaxies inside a cluster
The Coma Cluster includes its central giants and named spiral members at catalog positions, surrounded by a restrained statistical faint-member population.
Live data
Current Earth, Sun and observing conditions
Current satellite imagery, solar activity, aurora, weather and visible targets are available inside the main view.
Observing tools
Plan for the sky above you
Use your location, weather, equipment and the Moon to find worthwhile targets, then identify them in the live sky.
Evidence you can audit
Every number says where it came from
A source chip on each card names the engine or catalog and the snapshot age. Every bundled object also has a public evidence page listing what is measured, what is reconstructed and what is not documented yet.
In the field
Open it under the sky, with or without signal
Land straight in the live sky over your location with Identify, Tonight and Find one tap away. After one online visit the sky, planets, Tonight and station passes load offline, and sky alerts can reach the phone as push notifications.
Shareable tours
Record a journey, share it as a link
Record what you do in the app, save it as a script, and publish it as a tour link. Anyone who opens the link watches your flight in presentation mode, and nothing runs before they press Play.
Works offline, with push alertsTelescope mount controlYour sky photo, plate-solvedChanging stars and transitsDome projection and a phone remotePublic evidence pagesSpanish interfaceTwenty-five sky culturesShareable recorded toursCountdowns with email remindersGalactic dust and gas in 3DComplete exoplanet systemsBinary stars and pulsarsReal cluster membersHubble-dated giant planetsClock-driven planetary seasonsMeasured spatial stellar motionRedshift-resolved catalog galaxiesResolved supernova remnantsSurface terrain and skyMission trajectories
Recorded in the app
Recordings from the live model.
These are screen recordings from Space Time itself. No stock footage and no rendered cutaways.
Measured stellar motionLinear propagation of Gaia and HYG catalog velocities from 2026 to 7026 in exact 60 fps engine frames.Earth to the Coma Cluster323 million light-years in one continuous journey.Saturn and its ringsExact 60 fps engine frames from the live 3D scene.Sagittarius A*Gravitational lensing at the galactic center.
Made in the app
Featured tours.
Recorded flights through the real universe, scripted by people using Space Time. Press Play and watch.
From the Rosette’s glowing clouds to the Penguin and Egg galaxies: explore a larger collection of telescope-based destinations, with source observations and clear explanations of their reconstructed depth.
Explore nearby stellar nurseries, the shells of dying stars, and distant interacting galaxies. Every destination includes a telescope-based view, its original observation, and guidance on what to look for.
A ring galaxy, nested dust shells and two remarkable nebulae. Explore telescope-derived light fields, then inspect the source observations. The added depth is illustrative.
Look closer, check the evidence and keep the discoveries that interest you. These screenshots come directly from the explorer.
Collect story steps, put them in your own order and add notes. Export a collection to keep or share it, then use its destinations and captions in Journey Studio.
Inspect source maps, credits and coverage limits beside the world. Explore and Evidence use the same appearance descriptions as the public evidence pages.
Follow a story, inspect the evidence, plan time under the sky, or turn your route into a movie. These views were captured in the app.
Resume an unfinished story at the right destination, revisit saved discoveries, and choose an unstarted story. Your place is saved on this browser without an account.
Compare source imagery with your current 3D view. Registered Bullet Cluster layers offer an optical comparison wipe; source credits and limitations stay visible.
Build a 15-, 30- or 60-minute session for your location and gear. Use finder guidance, replace a target, add notes and log only what you actually observed.
Choose destination packs with visible download sizes, progress, resume and removal. Saved assets and controls work offline; live services and remote terrain still need a connection.
Every image below comes from the running app. Select one to inspect it at full size.
More from the model
Selected views.
Where it comes from
Sources and limitations are shown in the app.
Space Time combines catalogs, survey images and physics-based calculations. Reconstructions and visual exaggerations are identified in the interface instead of being passed off as observations.
Solar system
JPL-derived ephemerides and Horizons trajectories
Stars
Tycho-2, HYG and Gaia positions and measured motion
Yes. There is nothing to install, subscribe to or register for. The daily sky email is free too; it needs an account so it knows where you are.
Can I really fly from a planet to a galaxy?+
Yes. Planets, stars, survey-backed deep-sky objects, galaxies and large-scale structure share one navigable environment.
Is every part a direct observation?+
No. Positions and images come from real sources where available. Some paths, surfaces and invisible structures need reconstruction or visual scaling, and the app says so.
Can it tell me what is visible tonight?+
Yes. Set your location to see rise and set times, weather, lunar interference, telescope framing and a ranked list of targets.
Does it work on a phone?+
Yes. The interface adapts to phones and tablets and includes a device-orientation sky compass.
Does it work offline?+
For the essentials, yes. After one online visit the sky, planets, Tonight and ISS passes work without signal. Deep catalogs, survey imagery and live feeds need a connection, and the app says which is which.
Can it control my telescope?+
Yes, over ASCOM Alpaca, the plain-HTTP telescope standard. Run an Alpaca server such as ASCOM Remote on the machine you browse from, connect in the Mount panel, and slew to any selected object. Safety checks refuse targets below the horizon or near the Sun.
Is it available in other languages?+
The interface is available in Spanish: menus, Tonight, the selection card, the time bar and sign-in. Help and object descriptions are still English. Switch under Help, Language, or open the Spanish page.
Space Time renders the universe from real catalogs and computed ephemerides. Move through one continuous model from a planetary surface to the cosmic web, set any epoch and reference frame, replay missions, and plan what you can observe from where you stand.
Every object is searchable, and its position is computed for whatever date you set.
01 One continuous environment
From the local sky to large-scale structure.
Space Time unifies an orrery, a planetarium, an observing planner and a cosmic atlas. You investigate the same modeled environment at every spatial scale, epoch and observing location.
↗ Select any image to explore it full screen
02 Working modes
Three ways to use the model.
Navigate across astronomical scales, prepare an observing session for your own site, or reconstruct missions and historic events in their spatial and temporal context.
01
Navigate astronomical scales
Move between planetary surfaces, spacecraft, stellar neighborhoods and large-scale cosmic structure within one spatial model.
Every clip was generated and captured inside Space Time. No external astronomical footage or compositing was used.
Earth to the Coma Cluster323 million light-years in one continuous journey.Saturn and its ringsRing geometry, lighting and shadows in one scene.Sagittarius A*Gravitational lensing near the galactic center.
04 Selected views from the model
Plates.
From the archive · 20 additional plates
05 Scientific foundations
Built on real data and real physics.
Nothing here is keyframed. Change the date and everything moves to where it should be, from satellite passes to the precession of the equinoxes. It runs on desktop, mobile and WebXR headsets.
Yes. Explore without an account, subscription or download. It runs directly in a modern browser.
Can I travel from a planet to a galaxy in one view?+
Yes. Planets, stars, galaxies and the cosmic web live in one continuous 3D model, so you cross scales by moving through space rather than changing maps.
Is the simulation scientifically accurate?+
Positions come from Astronomy Engine's JPL-based ephemerides. Satellite tracking uses real TLE data and SGP4, while small-body data comes from JPL.
Can it help me observe the real sky tonight?+
Yes. Set your location to see visible planets and deep-sky objects, rise and set times, observing conditions, telescope framing and satellite passes.
Does it work on mobile and in VR?+
Yes. The interface adapts to phones and tablets, includes an AR sky compass, and supports WebXR headsets.
Space Time combines a navigable model of the universe with practical tools for exploring the real sky. Fly through the solar system, land on other worlds, follow spacecraft, and travel through millions of stars and thousands of galaxies. Then check what is visible tonight, plan an observing session, watch an eclipse, or frame a target for your telescope. Free in your browser, with no download or account required.
Launch Space TimeRuns in any modern browser · Works on desktop, phone & VRReal data, every object searchable and clickable
2.5Mstars
32,000+deep-sky objects
43,500galaxies
4,000+comets
7,700asteroids
187moons
5,600+planetary features
9,000live satellites
4,500quasars
Start with Earth. Keep zooming out.
Pull back from Earth and the planets come into view. Keep going and you pass nearby stars, the Milky Way, and thousands of galaxies in the local universe. There is no separate map for each scale. You move through the same 3D scene, then turn around and head back to a planet or moon.
Click a crater, comet, star, or galaxy to identify it. Its card shows the useful details for that kind of object, including distance, visibility, orbit, or observing information.
A continuous journey from Earth to the Coma Cluster, 323 million light-years away.
See it move
These short recordings show the 3D view in motion: Sagittarius A*, Saturn's ring system, the Sun, and mapped structure around the Great Attractor.
Every clip uses Space Time's own engine frames. No stock footage, generated astronomy or external cutaways.
Into Sagittarius A*, the Milky Way's black hole, lensing the stars behind it.Saturn and its rings in a deterministic 60 fps engine render.The Sun up close: a seething surface, prominences and corona.Through the Local Universe to the Great Attractor.
The solar system at any date
Planets, moons, dwarf planets, asteroids, and comets follow computed orbits and use real surface maps. Their positions come from Astronomy Engine, which uses JPL ephemeris data. Set the clock to now or choose another date.
Planets, moons, and smaller bodies
Visit Mercury through Neptune, plus Pluto, Ceres, and Eris. The major moons are rendered as 3D worlds, and all 187 named moons are searchable. You can also search roughly 4,000 comets and thousands of asteroids from JPL data.
Apollo & spacecraft
Replay the Apollo missions on their historical trajectories. You can also ride along with the ISS, Hubble, JWST and the Parker Solar Probe.
Travel through time
The clock scrubs forward and back through any date. Speed it up and alignments, conjunctions and retrograde loops play out in front of you.
Inspect real orbits and mission paths
Open Orbit for a planet or satellite, or Trajectory for an ephemeris-backed probe. See the actual sampled path without fake closed ellipses; JWST gets a one-circuit, co-rotating view centered on computed Sun–Earth L2.
Compare relative motion
Choose a compatible second object to inspect separation, relative velocity, opening or closing rate, and the next closest approach within the providers' disclosed model horizon.
Film an inertial flyby
Cinematic Coast preserves the camera's velocity while you look anywhere, giving smooth filming passes without pretending the camera is a spacecraft. Stop coast is always visible.
Saturn's current ring tilt and the shadow cast on the planet.Jupiter with the Galilean moons on their true orbits and real surface maps.The Sun, with a seething surface, prominences and corona.Earth with real relief and ocean sun-glint, lit by the actual Sun direction.Computed orbital directions over Mars's real ephemeris path, with the active reference frame disclosed.A real deep-space mission path: source coverage and interpolation are disclosed, while open trajectories remain open.JWST around computed Sun–Earth L2: one real sampled circuit in the frame that makes the halo motion understandable.Mars versus Earth in one shared frame and epoch, with the closest-approach search horizon disclosed.Cinematic Coast carries the camera on a fixed inertial vector while you compose the shot independently.
Click an object to learn more
Select a planet, nebula, or star to see what it is and whether you can observe it tonight. The card includes rise, transit, and set times, brightness, apparent size, and an equipment guide where those details apply. From there you can go to the object or share the view. Each card carries a short paragraph built from catalog facts, labelled as generated or authored, and a source chip that links to the object's public evidence page.
Click Saturn: when it rises, where it is, how big it looks, and that its rings show in any scope, with the full observer's readout below.The Lagoon Nebula, answered: well placed tonight, where to look, and a real survey image of what your telescope will show.
Stand on any world and look up
Choose a place on Earth, the Moon, or Mars and look at the sky from the surface. The Sun, planets, constellations, and Milky Way update for the place and time you select. You can also trace the Sun's analemma, follow a planet's retrograde loop, or run the clock across 28,000 years of axial precession.
Standing on the Moon. The sky above is the accurate one.“Tonight's Best”: ranked targets for your location, right now.The analemma, the Sun's year-long figure-8, traced in your sky.Deep Time: the sky of 2601 BCE, when Thuban marked the celestial pole.Dusk on Mars, with the sky computed for that spot and moment.A dark-site sky: 2.5 million stars, the Milky Way and the constellation lines.
Watch eclipses & sky events
Look up solar and lunar eclipses for a date and location, then watch from the ground or from space. The events calendar also covers lunar occultations and transits of Jupiter's moons. You can open an event in 3D or add it to your calendar. For major solar eclipses, the local companion shows contact times, obscuration, a countdown, and a cloud forecast during the final week. A Changing stars tab adds variable-star minima and maxima, exoplanet transits and nova alerts for your location.
Totality. The sky darkens and the corona appears.Replay the Apollo 11 mission in accurate 3D.Voyager 2's Grand Tour, Jupiter to Neptune, on the real trajectory.Mission instruments distinguish reconstructed Apollo and Artemis paths from ephemeris-derived Voyager and New Horizons states.A Galilean moon's shadow crawling across Jupiter, at the real times.The sky events almanac. Every entry opens in 3D and exports to your calendar.A total lunar eclipse, Earth's shadow turning the Moon blood-red.The August 12, 2026 eclipse from space: the Moon's shadow sweeping across Earth.The local eclipse companion shows contact times, obscuration, and a countdown. This example is for Reykjavík at 100%.
Live data from the sky
Space Time brings several live feeds into the model. The Sun uses current NASA Solar Dynamics Observatory imagery. Supernova and nova listings include visibility from your location, while comet forecasts use recent observer reports. You can also check the auroral oval and Kp index, follow near-Earth asteroid approaches, see what JWST is observing, and locate active deep-space missions. The "Happening now" feed collects the notable items and tells you which ones are visible from your location.
Today's sunspots mapped onto the 3D Sun with NASA SDO imagery.The brightest supernovae and novae in the real sky right now, with whether you can catch each one tonight.Switch the Sun to the 171Å extreme-ultraviolet view: today's real coronal loops, glowing over the active regions.JWST's current target, shown here for NGC 2808, with infrared and optical views of the field.Comet brightness, corrected with the real magnitudes observers are reporting now (the “live” comets, from COBS).Watch a near-Earth asteroid skim past Earth on its real trajectory, with the true miss distance ticking down live.Apophis passes inside the geostationary satellite ring in 2029.2001 WN5 passes inside the Moon's orbit in 2028 but remains well beyond the satellites.Open a past or upcoming close approach and watch it in 3D.Current positions for active deep-space missions, using JPL Horizons data.The "Happening now" feed covers novae, comet outbursts, close flybys, and aurora watches.
Beyond the solar system
The larger map includes 95,000 nearby stars placed with Gaia distances and 43,500 galaxies from the 2MASS Redshift Survey. Pull back far enough to see the local cosmic web and the microwave background.
Fly out to the Milky Way, with 95,000 real nearby stars you can click.The full NGC/IC catalog, with real survey imagery on the showpieces.The Virgo Cluster of galaxies, every catalogued object drawn as a chart symbol you can click to identify.The solar neighborhood: 95,000 nearby stars at their real Gaia distances.43,500 real galaxies (2MASS Redshift Survey), the cosmic web at its true shape.Laniakea's infall streams, every galaxy drifting toward the Great Attractor.Sagittarius A*, the Milky Way's black hole, lensing the starlight behind it.
An observer's toolkit
Plan an observing session with weather, visibility, ephemeris, equipment, and field-of-view tools. There is also a Moon calendar and an atlas with 277 named craters, maria, and landing sites.
Is it worth going out tonight?
A one-glance verdict for your location, scored from the real weather forecast: cloud cover, seeing (the jet stream), transparency, rain, the Moon and your light pollution (estimated automatically from your location). See the night hour by hour, how many hours are actually usable, and a seven-night outlook so you can pick the best evening to set up.
Interactive sky chart
The circular sky chart is drawn for your location and chosen time. Move the clock, zoom to bring in fainter stars, or select an object to identify it and open it in the planetarium.
Happening now
See current novae and supernovae, comet outbursts, close asteroid approaches, and geomagnetic storm watches. Each item includes brightness, equipment guidance, and visibility from your location.
A daily email about tonight's sky
Get an email before sunset with your observing forecast, visible planets, ISS passes, Moon conditions, comets, and other timely events. It is available worldwide and takes one click to unsubscribe.
Your local horizon
Space Time builds a horizon profile from elevation data around your location, so a nearby ridge can affect rise times and visibility. You can edit the profile to add trees and buildings.
Planet Watch
What each planet has turned toward Earth right now: when the Great Red Spot next crosses Jupiter's central meridian, which classic feature faces us on Mars, how open Saturn's rings are. Hit "Watch it" to set the clock and go to the Earth-facing side, with the spot marked on the globe.
My gear
Save your telescopes, eyepieces, binoculars and cameras once, and they drive everything: the simulator's field of view, the planner's "what can my scope actually reach tonight?" (the limiting magnitude comes from your aperture automatically), and the observation log records which gear you used. Works without an account; syncs when you sign in.
Telescope & eyepiece simulator
Check how a target fits your telescope, eyepiece, or camera sensor before setting up. The field-of-view overlay is drawn to scale on sky survey imagery.
Ephemeris generator
Generate almanac tables for any body: position, brightness, apparent size, over whatever date range you want. Export to CSV. Oppositions and best nights get flagged automatically.
ISS & satellite passes
Visible-pass predictions for the ISS, Tiangong and Hubble, computed from live TLEs with SGP4. It tells you when to go outside.
The whole satellite swarm
Turn on the full live Celestrak catalog, about 9,000 satellites, and watch them orbit Earth in real time, the dense Starlink shells and all. Search any one by name or NORAD number to pin it.
Real asteroid orbits
The brightest several thousand numbered asteroids from JPL, placed where they actually are. The true main belt appears between Mars and Jupiter, with the Jupiter Trojans bunched ahead of and behind the planet. Search Ceres, Vesta or Pallas to go to one.
Double & variable stars
Click Albireo or Mizar and see the separation and position angle to split the pair, with each component's colour. Click Mira or Algol and see its type, range, period and a light curve. Search any of them by name.
Observing programs
Work the Messier, Caldwell and Herschel 400 checklists. Browse every object, center it, and tick off what you've seen; your progress is saved. Each deep-sky object shows which programs it belongs to.
Build your own observing lists
Make as many named lists as you like and add to them from anywhere: an object's info panel, the right-click menu, or straight from a catalog. Pick one as your active list and every target on it is circled and labeled in the live sky, so you can see at a glance what's up and what's still to come. Sort by brightness or rise time, track what you've already caught, and share the list or export it as CSV.
AR camera sky
Turn on your phone camera and the star chart overlays whatever the lens is pointed at. It labels what you're looking at, and it works in daylight too.
Moon calendar & atlas
Daily phases, exact full-moon times, supermoon flags. The atlas side lets you go to Tycho, the maria or any Apollo landing site on the 3D Moon.
Deep sky & 2.5M stars
Over 32,000 deep-sky objects, more than a paid Plus-tier atlas: the full NGC/IC plus Sharpless, Arp, Abell, globular and open clusters, planetary nebulae and PGC galaxies, marked with the classic chart symbol and color-coded by type, against a sky of 2.5 million stars. Click any object to identify it, or search by catalog designation or common name.
Exoplanet systems
Search 4,684 confirmed systems and more than 6,200 planets from the NASA Exoplanet Archive. Filter by system type or habitable zone, compare an orbit with our Solar System, and see how a planet was detected. If the host star is up tonight, the page tells you where to look.
Live space weather & aurora
What the Sun is doing right now, from NOAA: the Kp index and the three space-weather scales (radio blackout, radiation and geomagnetic storm), the latest solar flare, the real-time solar wind, official storm watches, and your aurora chance for the next hour. The 3D Earth's auroral oval is driven by the live nowcast, sitting over the real offset magnetic pole.
Telescope mount control
Connect to an ASCOM Alpaca mount server on your network and slew, sync and park from the Mount panel or straight from an object's card, with horizon and solar-cone safety checks. On the https site the server runs on the same machine as the browser; help explains why.
Your sky photo
Drop in a night-sky photo. Solve it with astrometry.net or frame it by hand, and the app labels stars, constellations, deep-sky objects and planets from its own catalogs. Export a captioned PNG, or pin the photo over the live sky at the moment and place you took it.
Changing stars
Variable-star minima and maxima this week, exoplanet transits tonight, and nova and supernova alerts, each checked for your location and included in the daily email. Predictions carry their source and their timing caveat.
Works offline, with push alerts
After one online visit the sky, planets, Tonight and station passes load without signal, and a chip says what is cached. Turn on push notifications from your account page to get sky alerts on that device.
Dome, classroom and phone remote
A fisheye projection for domes and a planisphere view, shareable by link, plus a phone remote for live sessions with play, pause, rate, chapters and pinned targets. Presentation mode hides the chrome for a projector.
The sky chart for your location and time.The daily email: tonight's verdict, planets, ISS passes and highlights for your exact spot, before sunset.Saved gear feeds into the field-of-view simulator, planner, and observing log.The full live satellite catalog, about 9,000 objects, wrapping Earth in real time.The brightest numbered asteroids at their real positions, drawing the true main belt.Planet Watch marks the Great Red Spot at its true position, computed from the rotation model.Mars brightening toward its 2027 opposition in the ephemeris generator. The data exports to CSV.The Moon atlas: 277 named features and every landing site, clickable on the globe.AR camera mode, with the chart over the actual sky through your phone's lens.July 1054. The Crab supernova ignites where Chinese astronomers logged it.
A closer look
A few more of the places Space Time can take you, right out to the edge of the heliosphere.
Browse 4,684 confirmed exoplanet systems from the NASA archive.A transit animation shows how this exoplanet was detected.Your observing list, circled and labeled right on the sky, so you can see what's up tonight.Click a double star like Albireo for the separation and position angle to split it.Work the Messier, Caldwell and Herschel 400 checklists, with progress saved.Zoom in and 2.5 million stars keep appearing, the way a bigger scope would show them.Go to a named star and it becomes a seething disc, coloured by its real spectral type.Go into the Cassiopeia A supernova remnant, a 3D shell of expanding debris.Watch a coronal mass ejection race from the Sun to Earth and light the aurora.Earth's magnetosphere and Van Allen belts, drawn with their field lines.The heliosphere, with the spots where the Voyagers crossed into interstellar space.Pulsars sweep their beams at their real measured rates, down to the millisecond.Detailed spacecraft models: the James Webb Space Telescope out at L2.Ride a beam of light outward and watch it reach each planet in real time.The Milky-Way-core planner: when the galactic centre is high, dark and Moon-free.Live space weather: the Kp index, the R/S/G storm scales, flares, solar wind and NOAA's storm watches.The live auroral oval, sitting over the offset magnetic pole and driven by NOAA's nowcast.The Hertzsprung-Russell diagram, plotting real stars by colour and luminosity.What if Betelgeuse went supernova? Staged in your own sky at magnitude −11.Replay Shoemaker-Levy 9 hitting Jupiter in 1994, scar by scar.
Who uses it
Teachers run it in class. Stargazers use the planner before a night out, astrophotographers use the framing tools, and plenty of people just like flying around the planets. I built it because I wanted the orrery and the planetarium in one place; it grew from there. Free for classrooms, museums and home.
Yes. Free, no account, nothing to install. It runs in your web browser.
Do I need to download anything?
No. It runs in any modern browser with WebGL, on desktop, tablet and phone.
Can I really travel from a planet to a galaxy without switching views?
Yes. The planets, the stars, the galaxies and the cosmic web are one model at true scale, so you cross between them by zooming, not by loading a different screen. Pull back from Earth and you keep going all the way to the cosmic web; zoom back in and land on a moon. Anything you pass is clickable at any distance.
What planets are visible tonight?
Set your location, then open the observing planner or the Sky view. You get rise, transit and set times for the planets, the Moon and deep-sky objects.
Can I watch a solar or lunar eclipse?
Yes, for any date and location. Solar eclipses show totality with the corona; lunar eclipses get the blood-red umbra. Before a major eclipse, the local companion gives you your own contact times, obscuration percentage and a cloud-forecast go/no-go.
Can I get tonight's sky by email?
Yes. The free daily email delivers tonight's observing verdict, visible planets, ISS passes and Moon details for your exact location, before sunset in your timezone. One click to unsubscribe.
Can I stand on the Moon or Mars?
You can. The Sky view is a first-person planetarium from Earth, the Moon or Mars, with the sky computed for that world and moment.
Is it scientifically accurate?
Positions come from the astronomy-engine library (JPL ephemerides) and land within about an arcsecond. Satellite tracking uses real SGP4, and small-body data comes from JPL.
Can I see the ISS and other satellites?
Yes. Passes of the ISS, Tiangong and Hubble are predicted from real TLE data with SGP4, and you can jump the clock straight to one. You can also turn on the full live Celestrak catalog, about 9,000 satellites, and watch them orbit Earth in real time, then search any one by name or NORAD number.
Does it work on mobile and in VR?
It does. The interface adapts to phones, there's an AR sky compass, and WebXR / VR headsets are supported.
Space Time
