Do I need to download or install anything?

No. It runs in any modern browser with WebGL, on desktop, tablet and phone. Open the page and launch it.

Is Space Time scientifically accurate?

Positions come from the astronomy-engine library, which is built on JPL Development Ephemeris data, and they land within about an arcsecond of professional planetarium software. Satellites are tracked with real TLE + SGP4, and comet and asteroid data comes from JPL.

Does Space Time have an AI assistant?

Yes — the Sky Companion. Ask anything in plain language ('what's worth seeing tonight?', 'take me to Saturn', 'when does the ISS pass over me?') and it answers using the app's own astronomical computations for your exact location — never guessed numbers — while driving the 3D view: flying to objects, setting the time, staging eclipses and starting tours. It's free with an account, with a generous daily allowance.

Space Time

A working model of the universe, in your browser

Space Time is a free 3D universe explorer. Check where the planets are tonight, or stand on the Moon and look up. Then keep zooming out: past millions of stars, the Milky Way, and the cosmic web. Nothing to download, no account.

Launch Space Time Runs in any modern browser · Works on desktop, phone & VR Real 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

You are here, and here is everywhere

Start on Earth and pull back. The solar system shrinks to a dot, the Sun joins a field of neighbor stars, the stars gather into the Milky Way, and the galaxy becomes one speck among thousands in the cosmic web. It's all one place. There's no map screen and no scale picker to click through, and nothing reloads when you cross from a planet to the stars to the galaxies. You get there by moving, the way you actually would. Zoom back in and land on a moon. You never leave.

And any of it answers to a click. A crater on Mars, a comet passing tonight, a star 400 light-years off, a galaxy 200 million light-years off: same click, same instant card. Zoom out far enough and your whole solar system is a single point of light among the stars, and that point is still yours to fly back into.

One unbroken pull-back, from your backyard to the cosmic web. No cuts, no loading.

See it move

Screenshots only go so far for something built to fly through. A few more short clips: the August 2026 eclipse going to totality, a dive into the Milky Way's black hole, the flight through the Local Universe to the Great Attractor. Tap any to play.

Every clip was recorded live inside Space Time, in a browser, with the app's own clip recorder. No external footage.

The August 12, 2026 total solar eclipse, building to totality.

Into Sagittarius A*, the Milky Way's black hole, lensing the stars behind it.

Flying between worlds: Jupiter to Saturn to Earth.

The Sun up close: a seething surface, prominences and corona.

Through the Local Universe to the Great Attractor.

A real-time 3D model of the solar system

Every planet, moon, dwarf planet, asteroid and live comet rides its true orbit, rendered with real surface maps at 60fps. Positions come from the astronomy-engine library, which is built on JPL ephemeris data, so what you see on screen matches the actual sky.

All the planets & moons

Mercury through Neptune, plus Pluto, Ceres and Eris. The major moons are full 3D worlds you can fly to and stand on, and every named moon (all 187, down to the small irregular ones) is searchable, along with the full database of every known comet (about 4,000). The asteroid belt is in there too, pulled from JPL.

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.

Saturn and its rings rendered in 3D with the ring shadow on the planet — Saturn, rings and ring-shadow, tilted exactly as it is right now.

Jupiter with the Galilean moons Io, Europa, Ganymede and Callisto on their orbits — Jupiter with the Galilean moons on their true orbits and real surface maps.

The Sun rendered with a seething surface, prominences and corona — The Sun, with a seething surface, prominences and corona.

Earth in 3D with ocean sun-glint and relief shading from real elevation data — Earth with real relief and ocean sun-glint, lit by the actual Sun direction.

Click anything, and it answers

Click a planet, a nebula or a star and the same plain-language card opens. What is it? Can I see it tonight from where I am? Where is it in the sky right now? What would it look like in binoculars or a telescope? Then fly there, or share the exact view. The answers come first, in words, with the full observer's data, rise, transit and set times, brightness, apparent size, a tap below.

The Saturn answer card in Space Time: a plain-language summary of when it rises, where it is in the sky, its brightness and apparent size, and how its rings look in a telescope, beside the 3D ringed planet — 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 answer card in Space Time, showing whether it is visible tonight, where it is in Sagittarius, and a real DSS2 survey image of what the nebula looks like through a telescope — 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

Drop to the surface of Earth, the Moon or Mars. The Sun, Moon, planets, constellations and the Milky Way appear exactly as they would from that spot at any date and time, so it doubles as a what's-up-tonight view. You can trace the Sun's analemma figure-8 onto the sky, or a planet's retrograde loop. Deep Time goes further: scrub through 28 millennia of axial precession and watch the pole star pass from Thuban, the pyramid builders' north star, to Polaris and on toward Vega.

First-person planetarium view of the night sky from the surface of the Moon — Standing on the Moon. The sky above is the accurate one.

Tonight's Best observing planner ranking visible planets and deep-sky objects — “Tonight's Best”: ranked targets for your location, right now.

The Sun's analemma figure-8 traced across the daytime sky over New York — The analemma, the Sun's year-long figure-8, traced in your sky.

Deep Time view of the sky in 2601 BCE with Thuban in Draco as the pole star — Deep Time: the sky of 2601 BCE, when Thuban marked the celestial pole.

First-person view of the Martian sky from the surface of Mars at dusk — Dusk on Mars, with the sky computed for that spot and moment.

The night sky from a dark site filled with stars, the Milky Way and constellations — A dark-site sky: 2.5 million stars, the Milky Way and the constellation lines.

Watch eclipses & sky events

The eclipse view predicts solar and lunar eclipses for any date and place, then plays them out: totality with the Sun's corona, or Earth's shadow turning the Moon blood-red, viewed from the ground or from space. There's a full sky events calendar too. Lunar occultations are computed for your location, and Jupiter's moons transit and cast shadows at the real times, including the rare double shadow transits. Every event opens in 3D with one click and exports to your calendar. When a major solar eclipse is coming, a local eclipse companion answers the questions that actually matter for your spot: whether it's visible from where you stand, your exact first-contact, maximum and last-contact times in local time, the obscuration percentage, a live countdown, and — in the final week — a cloud-forecast go/no-go for eclipse hour.

Total solar eclipse with the Sun's corona visible at totality — Totality. The sky darkens and the corona appears.

Apollo 11 mission trajectory from Earth to the Moon recreated in 3D — Replay the Apollo 11 mission in accurate 3D.

Voyager 2 at Neptune in 1989 during the Grand Tour mission replay — Voyager 2's Grand Tour, Jupiter to Neptune, on the real trajectory.

Europa's shadow crossing Jupiter's cloud tops during a shadow transit — A Galilean moon's shadow crawling across Jupiter, at the real times.

Sky events calendar listing Jupiter moon transits, shadow transits and lunar occultations — The sky events almanac. Every entry opens in 3D and exports to your calendar.

A total lunar eclipse turning the Moon deep red during totality — A total lunar eclipse, Earth's shadow turning the Moon blood-red.

The Moon's shadow crossing Earth during a solar eclipse, seen from space — The August 12, 2026 eclipse from space: the Moon's shadow sweeping across Earth.

The local eclipse companion showing the August 12 2026 total solar eclipse from Reykjavík: 100% obscuration, first contact, maximum and last contact in local time, a live countdown and eye-safety guidance — The local eclipse companion: your own contact times, obscuration and countdown — here Reykjavík at 100%.

The real sky, right now

Space Time isn't only a model — much of it is live. The 3D Sun is re-skinned with today's real imagery from NASA's Solar Dynamics Observatory, so you see the actual sunspots and coronal loops on the Sun right now, switchable between the visible photosphere and the extreme-ultraviolet corona. The brightest supernovae and novae flaring in the real sky are listed brightest-first, each with its type and host galaxy, whether you can catch it from your location tonight, and a push-to guide to point you straight at it. The comet forecasts are corrected with the real magnitudes observers are reporting right now, and you can see what the James Webb Space Telescope is pointed at this very minute. The live auroral oval and Kp index, near-Earth asteroid close approaches and the full ~9,000-satellite swarm are all driven by real-time data too. You can watch any of those near-Earth asteroids — or famous close approaches like Apophis threading inside the geostationary satellites in 2029 — skim past Earth along its exact JPL Horizons trajectory, with the real miss distance ticking down in lunar distances, and see precisely where every active deep-space mission (Voyager, Parker Solar Probe, JWST, New Horizons, Lucy and more) is flying at this moment, then fly out to it or ride along at its real speed. And you don't have to go looking: a curated "Happening now" feed watches all of it for you — a nova flaring into binocular range, a comet in outburst, an asteroid about to thread inside the Moon's orbit, a geomagnetic storm watch — and tells you, for each one, whether you can see it from your own backyard tonight.

The Sun in Space Time rendered from today's real NASA Solar Dynamics Observatory imagery, showing the actual current sunspot groups, in the solar-system view — The 3D Sun, re-skinned with today's real NASA SDO imagery — the actual sunspots on the Sun right now.

A live list of the brightest supernovae and novae currently flaring in the sky, each with its type, host galaxy, magnitude, constellation and tonight's visibility from the observer's location — The brightest supernovae and novae in the real sky right now, with whether you can catch each one tonight.

The Sun shown in NASA SDO's 171-ångström extreme-ultraviolet channel, revealing today's golden coronal loops and active regions — Switch the Sun to the 171Å extreme-ultraviolet view: today's real coronal loops, glowing over the active regions.

What the James Webb Space Telescope is observing right now from the live STScI schedule — the globular cluster NGC 2808 — with infrared (WISE) and optical (DSS2) cutouts of that patch of sky — What JWST is pointed at this very minute — here NGC 2808 — with the patch of sky it's framing, in infrared and optical.

The comet brightness forecast with live observed magnitudes from COBS, each comet flagged 'live' with its real recent magnitude — Comet brightness, corrected with the real magnitudes observers are reporting now (the “live” comets, from COBS).

A near-Earth asteroid, 2026 MC2, shown at its closest approach to Earth on its real JPL Horizons trajectory, with a live readout of the miss distance in lunar distances, closing speed and size — Watch a near-Earth asteroid skim past Earth on its real trajectory, with the true miss distance ticking down live.

Asteroid 99942 Apophis at its April 13 2029 closest approach, passing about 38,000 km from Earth's centre — inside the ring of geostationary satellites, drawn to scale — on its exact JPL Horizons trajectory, flagged as a potentially hazardous asteroid — Ride along with famous close approaches — like Apophis in 2029, threading inside the geostationary-satellite ring at 38,000 km.

Asteroid 2001 WN5 at its 2028 closest approach, 0.65 lunar distances from Earth — shown to scale between the geostationary-satellite ring and the ring of the Moon's orbit — Every flyby is a true-scale diagram: 2001 WN5 in 2028 passes inside the Moon's orbit but well beyond the satellites.

The Asteroid Flybys panel listing famous and upcoming close approaches — Apophis 2029, 2001 WN5 2028, 2023 BU, 2012 DA14, Toutatis — each with its story and a Watch the flyby button — A menu of famous and upcoming close approaches — Apophis, 2023 BU, Toutatis and more — each one watchable in a tap.

A live list of active deep-space missions — Parker Solar Probe, Solar Orbiter, BepiColombo, Juno, Lucy, Psyche and more — each showing its real current distance from the Sun and Earth, light-travel time and speed from JPL Horizons — Where every active deep-space mission is right now, live from JPL Horizons — fly out to any of them, or ride along.

The Happening now feed listing live sky alerts — a geomagnetic storm watch, a bright nova and a close asteroid flyby — each with a personal visibility verdict for the observer's location — "Happening now": novae, comet outbursts, close flybys and aurora watches, each with a can-I-see-it verdict for your spot.

From the solar system to the edge of the universe

Out past the planets you reach the real universe, and it's all really out there: 95,000 nearby stars at their true Gaia distances, the full sweep of the Milky Way, then 43,500 real galaxies from the 2MASS Redshift Survey drawn where they actually sit, forming the cosmic web out to the microwave background at the edge of the observable universe. Fly into any of it.

3D view of the Milky Way galaxy with the Sun's position marked — Fly out to the Milky Way, with 95,000 real nearby stars you can click.

The Andromeda Galaxy shown with real deep-sky survey photography — The full NGC/IC catalog, with real survey imagery on the showpieces.

The NGC/IC catalog drawn as color-coded chart symbols over the Virgo Cluster, with Messier galaxies labeled — The Virgo Cluster of galaxies, every catalogued object drawn as a chart symbol you can click to identify.

The Sun's stellar neighborhood in 3D with the nearest stars at their real distances — The solar neighborhood: 95,000 nearby stars at their real Gaia distances.

43,500 real galaxies from the 2MASS Redshift Survey forming the cosmic web — 43,500 real galaxies (2MASS Redshift Survey), the cosmic web at its true shape.

The Laniakea supercluster flow lines converging toward the Great Attractor — Laniakea's infall streams, every galaxy drifting toward the Great Attractor.

The supermassive black hole Sagittarius A-star gravitationally lensing the stars behind it — Sagittarius A*, the Milky Way's black hole, lensing the starlight behind it.

An observer's toolkit

Tools for people who actually haul a telescope outside. There's an ephemeris generator with almanac tables, brightness and distance graphs, and CSV export for any planet. A Moon phase calendar flags supermoons, and the clickable Moon atlas puts 277 named craters, maria and landing sites on the 3D globe.

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

A live planisphere of your whole sky — the classic circular all-sky chart, drawn for your location and any moment you pick. Scrub the date and time, zoom in and fainter stars keep appearing, and click any star or planet to identify it or jump to it in the planetarium view. Live alerts appear right on the chart.

Happening now: live sky alerts

The sky changes, and Space Time watches it for you. Bright novae and supernovae, comets in outburst, asteroids about to skim past Earth and geomagnetic storm watches surface automatically as a curated feed — each one with a personal verdict: how bright, what you need to see it, and how high it climbs over your horizon tonight.

A daily email about tonight's sky

One free email before sunset, written for your exact location: tonight's worth-going-out verdict, which planets are up and when, visible ISS passes, the Moon's phase and interference, comets and anything unusual happening overhead. Global — it works for Sydney and São Paulo just as well as for London. Unsubscribe in one click.

Your real horizon

Not the idealised flat horizon — yours. Space Time reads the actual terrain around your location from elevation data and builds the true skyline: the ridge to the southeast, the hill that blocks low planets. Every rise time and "can I see it" verdict respects it, and you can drag-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 fly 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 scope, eyepiece or camera sensor before you set up — pick straight from your saved gear. The field-of-view overlay is drawn to scale on real sky 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 fly 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 fly 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

Every confirmed planetary system from the NASA Exoplanet Archive — 4,684 systems, 6,200+ planets — searchable by host star or planet and filterable by habitable-zone worlds, multi-planet systems and more. Fly into any one: the planets ride their true eccentric orbits, driven by the same time controls as the solar system, with the habitable zone shaded and a Solar System comparison overlay. A "How we found it" animation replays each planet's discovery — the transit dip or the radial-velocity wobble — and if the host star is above your horizon tonight, it 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.

The interactive whole-sky chart: a circular planisphere of the entire sky for the observer's location and time, with constellations, planets and clickable stars — The interactive sky chart — your whole sky as a live planisphere. Zoom in and fainter stars keep coming.

The daily tonight's-sky email showing the night's observing verdict, a sky chart, planet visibility times, ISS passes and Moon details for the reader's location — The daily email: tonight's verdict, planets, ISS passes and highlights for your exact spot, before sunset.

The My Gear equipment locker holding a saved telescope, eyepiece and camera, each with its specs and the magnitude it reaches — Save your gear once — it drives the simulator's field of view, the planner's limits, and the log.

About 9,000 live Celestrak satellites rendered as a shell orbiting Earth in real time — The full live satellite catalog, about 9,000 objects, wrapping Earth in real time.

Thousands of real numbered asteroids drawing the true main belt between Mars and Jupiter — The brightest numbered asteroids at their real positions, drawing the true main belt.

Jupiter with the Great Red Spot marked at its true position by Planet Watch — Planet Watch marks the Great Red Spot at its true position, computed from the rotation model.

Ephemeris generator graphing Mars brightness toward its 2027 opposition with CSV export — Mars brightening toward its 2027 opposition in the ephemeris generator. The data exports to CSV.

Moon atlas labeling maria, craters and Apollo landing sites on the 3D Moon — The Moon atlas: 277 named features and every landing site, clickable on the globe.

AR camera mode overlaying the star chart on the real night sky through the phone camera — AR camera mode, with the chart over the actual sky through your phone's lens.

The Crab supernova of 1054 blazing beside Tianguan in the simulated medieval sky — 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.

The exoplanet browser listing 4,684 real planetary systems from the NASA Exoplanet Archive, searchable and sortable by distance, planet count and habitable zone — Every confirmed exoplanet system — 4,684 of them, from the NASA archive. Open any one to fly into it.

The How we found it discovery animation for an exoplanet, replaying the transit method with the light curve dipping as the planet crosses its star — "How we found it": every exoplanet replays its own discovery — here the transit dip, live in the light curve.

An observing list highlighted in the night sky, with M13, Vega, M57, Deneb and Altair each circled and labeled — Your observing list, circled and labeled right on the sky, so you can see what's up tonight.

The double star Albireo identified with its separation, position angle and component colours — Click a double star like Albireo for the separation and position angle to split it.

The Caldwell observing program checklist with progress tracking — Work the Messier, Caldwell and Herschel 400 checklists, with progress saved.

The 2.5 million star Tycho-2 catalog filling the sky down to magnitude 13 — Zoom in and 2.5 million stars keep appearing, the way a bigger scope would show them.

A close-up of Betelgeuse showing its orange-red seething surface and glare — Fly to a named star and it becomes a seething disc, coloured by its real spectral type.

The Cassiopeia A supernova remnant as a 3D model of expanding debris — Fly into the Cassiopeia A supernova remnant, a 3D shell of expanding debris.

A coronal mass ejection racing from the Sun toward Earth in the solar storm theater — Watch a coronal mass ejection race from the Sun to Earth and light the aurora.

Earth's magnetosphere and Van Allen belts visualised with field lines — Earth's magnetosphere and Van Allen belts, drawn with their field lines.

The heliosphere bubble with the Voyager spacecraft crossing into interstellar space — The heliosphere, with the spots where the Voyagers crossed into interstellar space.

A pulsar with its sweeping radio beams, flashing at its real rotation rate — Pulsars sweep their beams at their real measured rates, down to the millisecond.

A detailed 3D model of the James Webb Space Telescope at the L2 point — Detailed spacecraft models: the James Webb Space Telescope out at L2.

Riding a beam of light outward from the Sun as a expanding wavefront — Ride a beam of light outward and watch it reach each planet in real time.

The bright Milky Way core rising over a dark horizon for astrophotography planning — The Milky-Way-core planner: when the galactic centre is high, dark and Moon-free.

The Space Weather card showing live Kp, the R S G storm scales, a G3 geomagnetic storm watch, the latest flare and solar wind, beside the aurora on the 3D Earth — Live space weather: the Kp index, the R/S/G storm scales, flares, solar wind and NOAA's storm watches.

The live auroral oval over Earth's night side, offset over the geomagnetic pole, driven by the NOAA OVATION nowcast — The live auroral oval, sitting over the offset magnetic pole and driven by NOAA's nowcast.

A Hertzsprung-Russell diagram plotting stars by temperature and luminosity — The Hertzsprung-Russell diagram, plotting real stars by colour and luminosity.

A simulation of Betelgeuse exploding as a supernova bright enough to see in daylight — What if Betelgeuse went supernova? Staged in your own sky at magnitude −11.

Comet Shoemaker-Levy 9 fragments striking Jupiter and leaving dark impact scars — 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.

Explore Space Time

Pick a starting point:

3D solar system What's in the sky tonight Solar & lunar eclipse simulator Stand on the Moon or Mars Apollo missions in 3D Deep-sky explorer Fly through the cosmic web Exoplanet systems Telescope field-of-view simulator Space Time vs Stellarium Space Time vs SkySafari ISS & satellite passes Relive historic skies

Frequently asked questions

Is Space Time free?

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.

Launch Space Time