ORBITAL
We are small.
The universe is not.
Let’s go further.
A slowly rotating Earth seen from orbit, with the day side lit by the Sun and city lights on the night side. Drag to rotate the planet; click or press Begin journey to travel outward to the Solar System.
An interactive model of the Sun and eight planets moving on their orbits. Use the planet buttons to read each planet's distance from the Sun, orbital period and speed. The time control speeds the simulation from 1 to 1,000 simulated days per second. The scale toggle switches between a compressed view and true proportions.
Twisted magnetic fields snap and reconnect, releasing a burst of energy and light.
A rendering of the Sun's visible surface: granulation cells, darker sunspots, a dimmer edge from limb darkening, and red prominences at the rim. Scrolling moves closer to the Sun; near the end a solar flare erupts from the edge and fills the view with light. The Sun is about 1.39 million km across; its surface is about 5,500 °C and its core about 15 million °C.
Light crosses 299,792 km every second — the fastest anything can travel. Distance in space is so large that even light has to wait.
8 min 19 sec.
The sunlight on your skin right now left the Sun about eight minutes ago.
The smallest planet races around the Sun in just 88 days. Its orbit is stretched, so it speeds up as it swings close and slows as it climbs away — watch the speed change.
Mercury racing around the Sun on a stretched orbit, inside Earth's much larger and slower orbit. Mercury moves about 59 km/s at its closest point to the Sun and about 39 km/s at its farthest, completing four laps for every one of Earth's.
Venus is almost Earth's twin in size. Its air is 96% carbon dioxide — and it is the hottest planet in the Solar System, even though Mercury is closer to the Sun.
~70 km up. Clouds of sulfuric acid droplets cover the whole planet.
~50 km up, pressure is about the same as at sea level on Earth.
464°C — hot enough to melt lead. Pressure is about 92 times Earth's.
Sunlight gets through the clouds and warms the ground. The thick carbon dioxide traps that heat and won't let it escape — so the surface stays scorching, day and night.
Venus seen from space as a pale yellow disc, then a descent through thick yellow-orange clouds that grow darker and redder with depth, ending above a dim, hot, rocky plain. Readouts note the cloud tops at about 70 km, Earth-like pressure at about 50 km, and a surface of 464 °C at about 92 times Earth's pressure.
Slow solar wind. Aurora stays faint, close to the poles.
A simplified simulation. Particles stream from the Sun on the left toward Earth on the right. Earth's magnetic field, drawn as looping lines, deflects most of them around a boundary called the magnetopause. A fraction are guided down toward the north and south poles, where the aurora glows. Stronger solar wind squeezes the field closer to Earth and sends more particles to the poles.
Charged particles guided by Earth's magnetic field strike gases high in the atmosphere, and the gases glow. Oxygen gives the common green; nitrogen adds blues and purples.
Slowly moving curtains of green, cyan and violet light above a dark horizon. Moving the pointer makes the curtains lean gently toward it.
A cutaway of Earth with one eighth removed. As you scroll, the removed slice separates into its layers, which drift outward and then rejoin. From the outside in: a thin rocky crust, a thick mantle of hot slowly flowing rock, a liquid iron outer core, and a solid iron inner core.
The Sun always lights half of the Moon. What changes is how much of that lit half faces us. Drag the Moon around its orbit, or use the slider.
First quarter
The Moon's gravity stretches Earth's oceans into two bulges — one facing the Moon, one opposite. As Earth turns beneath them, coastlines see two high tides a day. The phase cycle is longer than the orbit because Earth moves around the Sun meanwhile.
crosses Earth.
Only people inside the narrow path of the Moon's darkest shadow see totality. Everyone nearby sees a partial eclipse.
NASA Science — EclipsesA view of the sky from the ground during a total solar eclipse. As you scroll, the Moon slides across the Sun and the daylight sky darkens. At totality the Moon covers the Sun completely, revealing the faint white corona and small red prominences, while the horizon glows like sunset. A small diagram shows the Sun, Moon and Earth in a line, with the tip of the Moon's dark shadow touching Earth.
A cold desert of iron-rich dust. Drag to drive.
Leftovers from the birth of the planets, mostly between Mars and Jupiter. Scroll to fly through; select a named asteroid.
A flight through a field of tumbling grey rocks. Six real asteroids are marked and selectable: 4 Vesta, 2 Pallas, 10 Hygiea, 16 Psyche, 433 Eros, 101955 Bennu.
Meteoroid — a small piece of rock or dust drifting in space. (Large ones are asteroids.)
Meteors can appear anywhere in the sky, but trace them backwards and they all point to one spot — the radiant. Earth is ploughing through a stream of debris left by the comet 109P/Swift–Tuttle.
A giant storm, wider than Earth, observed for well over 150 years. It has been slowly shrinking.
Its four largest moons, first seen by Galileo in 1610, line up along its equator — the inner three keep a precise 1 : 2 : 4 rhythm.
Jupiter, a banded gas giant with the Great Red Spot storm in its southern half. Scrolling brings it closer until it fills the view, then pulls back to show Earth beside it to scale: Jupiter is about 11 times wider. Its moons Io, Europa and Ganymede appear as points along its equator.
Scroll to fly down into them.
Ice, in orbit.
Countless pieces of water ice — from dust grains to chunks the size of a house — each circling Saturn on its own orbit.
Wide, and astonishingly thin.
The main rings span about 280,000 km, yet in most places are only around 10 metres thick.
Gaps carved by moons.
The Cassini Division, a 4,800-km gap, and the narrow Encke Gap are kept clear by the gravity of Saturn's moons.
Saturn and its rings seen from above, then a flight down into the ring plane between countless icy particles, with the planet's shadow falling across the rings. The rings show their real structure: the faint C ring, the dense B ring, the dark Cassini Division gap and the A ring with the narrow Encke Gap.
Uranus is tipped over by about 98° — its spin axis lies almost flat against its orbit. It rolls around the Sun on its side, probably knocked over by a giant collision long ago.
North pole faces the Sun — northern summer.
Because the axis keeps pointing the same way in space, each pole gets roughly 42 years of continuous sunlight, then 42 years of darkness.
Uranus drawn spinning on its side, its axis tilted about 98 degrees from upright, beside Earth tilted 23 degrees for comparison. Below, a diagram of Uranus going around the Sun: as the year advances, first one pole, then the equator, then the other pole faces the Sun.
Sunlight here is about 900 times fainter than on Earth, and 4 h 10 min old. Yet Neptune has the fastest winds measured in the Solar System — over 2,000 km/h. Its moon Triton orbits backwards, against the planet's spin.
Neptune, a deep blue planet with white high clouds and a dark storm, far from a Sun that appears only as a bright star. Its moon Triton circles it in the opposite direction to the planet's rotation.
Past Neptune, the worlds get small, cold and far apart. These dwarf planets are round, orbit the Sun — but haven't cleared their paths of other debris.
Hover or select a dwarf planet.
A vast ring of icy bodies beyond Neptune, from 30 to about 50 AU. Pluto is one of them — its stretched orbit even dips inside Neptune's.
The edge.
Around 120 AU, the Sun's wind finally gives way to interstellar space. Voyager 1 crossed this boundary in 2012 — the first human-made object to do so.
A top-down map of the outer Solar System. Thousands of icy objects circle the Sun beyond Neptune's orbit, the farther ones moving more slowly. Pluto's elongated orbit crosses inside Neptune's. Zooming out reveals the heliopause at about 120 AU.
Follow a beam of sunlight.
It passes the planets in hours. Our farthest spacecraft, after nearly 50 years, is about a light-day out.
One light-year.
A light-year is a distance, not a time: how far light travels in a year — about 9.46 trillion km. The whole Solar System is now a dot at the start of the line.
4.24 years.
The light reaching us tonight from Proxima Centauri, the nearest star, set out over four years ago.
Toward the neighbours.
A beam of light leaves the Sun. As it travels, the view widens: it passes Earth after 8 minutes, Neptune after about 4 hours, the Voyager 1 spacecraft after nearly a day, and reaches one light-year after a year — by then the Solar System is a single point. Proxima Centauri, the nearest star, lies 4.24 light-years away.
Every star system within about 11 light-years, in its true position around the Sun. Most are red dwarfs — too faint to see without a telescope. Drag to turn the map.
Proxima Centauri
The closest star to the Sun. It has at least one known planet.
A 3D map of the stars nearest the Sun: Proxima Centauri, 4.24 light-years; Alpha Centauri A & B, 4.37 light-years; Barnard's Star, 5.96 light-years; Wolf 359, 7.86 light-years; Lalande 21185, 8.31 light-years; Sirius A & B, 8.6 light-years; Luyten 726-8, 8.73 light-years; Ross 154, 9.69 light-years; Ross 248, 10.3 light-years; Epsilon Eridani, 10.5 light-years; Lacaille 9352, 10.7 light-years; Ross 128, 11 light-years; 61 Cygni A & B, 11.4 light-years; Procyon A & B, 11.46 light-years.
A few hundred billion stars in a barred spiral. The Sun takes about 230 million years to orbit the centre once.
Choose a destination, or drag to turn the galaxy.
A model of the Milky Way seen from outside: a glowing central bar and bulge with spiral arms winding outward. The Sun is marked about halfway out, in a small arm called the Orion Spur. The centre holds the black hole Sagittarius A*.
Our neighbourhood.
The Milky Way belongs to the Local Group — dozens of galaxies, mostly small dwarfs, bound together by gravity.
Andromeda is heading our way at about 110 km/s. A collision has long been predicted in about 4–5 billion years; newer studies say a merger is likely, but not certain.
Stars don't crash.
Stars are so far apart that almost none will collide. Gravity does the work instead — flinging stars out into long tidal tails.
One galaxy.
After repeated passes, the two could settle into a single, rounder giant galaxy.
A simulation of the Milky Way and Andromeda approaching each other. As you scroll, they swing close, gravity pulls long tails of stars out of both disks, they separate, fall back together and finally merge into one rounded galaxy.
Galaxies come in a handful of basic shapes, first sorted by Edwin Hubble in the 1920s.
Spiral
A flat, rotating disk with spiral arms where new stars form, around a bulge of older stars.
A rotating model of a spiral galaxy. A flat, rotating disk with spiral arms where new stars form, around a bulge of older stars.
Nebulae are vast clouds of gas and dust. Some are nurseries for new stars; others are what a star leaves behind when it dies.
Orion Nebula (M42)
The closest large region of star birth to Earth — visible to the naked eye as a fuzzy patch in Orion's sword.
See the real telescope image →A slow drift through glowing clouds of gas and dark dust, coloured to evoke the Orion Nebula (M42). The closest large region of star birth to Earth — visible to the naked eye as a fuzzy patch in Orion's sword.
A cold, dark cloud of hydrogen and dust drifts in space — light-years across.
A cloud of gas particles is drawn inward by gravity. As it shrinks it spins faster and flattens into a disk around a growing, glowing centre, which shoots jets from its poles and finally ignites as a star.
Birth
A protostar settles down as hydrogen fusion begins in its core.
A star drawn at each stage of its life. Sun-like stars swell into red giants and end as white dwarfs; massive stars become supergiants, explode as supernovae scattering newly made elements, and leave a neutron star or black hole.
Apart from hydrogen, almost every atom in your body was forged inside a star and scattered when it died.
Oxygen
Made mainly in massive stars and released when they explode. Most of your body's mass.
More mass than the Sun, crushed into a ball about 20 km across. A teaspoon of it would weigh about a billion tonnes. Its magnetic field funnels beams of radiation from its poles; as it spins, the beams sweep space like a lighthouse.
A spinning neutron star with magnetic field loops tilted from its spin axis. Two beams of light sweep around as it turns; each time a beam points toward the viewer, the screen flashes — a pulse.
A black hole's gravity is so strong it bends the paths of light. Stars behind it are smeared into arcs; the far side of its glowing disk is lifted into view above and below.
Beyond this point, light cannot return.
The event horizon is not a surface — it's a point of no return. The black disc is its shadow: the region from which light was captured. Nothing inside can be seen.
A ring of trapped light.
Just outside, light can loop around the black hole before escaping, forming a thin, bright ring. In 2019 and 2022 the Event Horizon Telescope imaged such rings around M87* and Sagittarius A*.
A black hole: a black disc surrounded by a thin bright ring of light and a glowing orange accretion disk whose far side appears bent up over the top and under the bottom. Background stars are smeared into arcs around it.
A massive galaxy or cluster between us and a more distant galaxy bends its light. Add mass, and watch the distant galaxy stretch into arcs — then, when perfectly lined up, a ring.
Arcs: the galaxy is stretched and split into multiple images.
Two dead stars, circling.
Two black holes orbit each other, losing energy as ripples in space itself — spiralling closer, faster and faster.
They merge. A burst of gravitational waves races outward at the speed of light, stretching and squeezing space as it passes.
Heard on Earth.
On 14 September 2015, LIGO caught such a signal from black holes that merged about 1.3 billion years ago — a change in its 4-km arms smaller than a ten-thousandth of a proton's width.
Two glowing objects circle each other ever faster at the centre of a grid. Ripples spread outward, stretching the grid in one direction and squeezing it in the other. The objects merge, the ripples ring briefly and fade. A trace below rises into a short chirp.
More than 6,000 planets have been confirmed around other stars. Most are far too small and dim to photograph — we find them by the tiny effects they have on their stars.
The transit method
When a planet passes in front of its star, the star dims very slightly. Repeated dips reveal the planet's size and orbit.
Pull back.
A dot.
Everything we know exists on that dot.
The camera pulls away from Earth until it is a single pale blue pixel in darkness, about 6 billion kilometres away — roughly where the Voyager 1 spacecraft was in 1990 when it turned to look back. Everything we know exists on that dot.
About 380,000 years after the Big Bang, the universe cooled enough for light to travel freely. That light is still arriving from every direction — stretched by 13.8 billion years of cosmic expansion into faint microwaves.
The spots differ by only about one part in 100,000 — the seeds that later grew into galaxies. Slide back in time and the same light glows orange-hot. Expansion has since stretched its wavelength about 1,100-fold — a redshift that turned visible glow into microwaves.
On the largest scales, galaxies aren't scattered evenly. They gather in clusters, strung along vast filaments around enormous, nearly empty voids.
Scaffolding we can't see.
Most of the web's mass is dark matter — invisible, detected only by its gravity. Galaxies formed where it pooled, like dew along threads.
The observable universe.
About 93 billion light-years across: the region from which light has had time to reach us since the Big Bang. We sit at its centre — as would any observer.
And beyond?
The entire universe is not the same as the observable one. It may be far larger, perhaps infinite. Its full extent is unknown.
A flight through a three-dimensional network of glowing threads and knots — galaxy clusters joined by filaments, with dark empty voids between. The view pulls back to show the whole web inside a faint boundary marking the edge of the observable universe; beyond it, a ghostly continuation suggests the universe goes on.
Our eyes see a thin slice of light. Telescopes tuned to other wavelengths — many of them in space, above the atmosphere that blocks most of it — reveal entirely different universes. Drag across the spectrum.
Visible
Starlight and glowing gas — what our eyes see.
Sound is a pressure wave passed from molecule to molecule. Space is very nearly empty, so ordinary sound can't travel through it — the universe is silent to our ears.
What we can do is turn data into sound. Here, each planet plays a note once per orbit — faster orbits sing higher. Mercury chirps every ~0.6 s; Neptune once every ~6.5 minutes.
Drag through time. Switch to the true scale to feel how late we arrived.
Space age
1957: Sputnik 1, the first artificial satellite.
Dec 31, 11:59:59 pm
He saw mountains on the Moon and four moons circling Jupiter.
A 2.5-second flight that pointed the way to every modern launcher.
The Space Age begins.
One orbit of Earth in 108 minutes.
Nearly three days in orbit.
About 12 minutes outside the spacecraft.
Twelve people walked on the Moon between 1969 and 1972.
The start of living and working in orbit.
The first long-lived lander on Mars, sending back the first clear surface images.
A grand tour of the outer planets — still sending data from interstellar space.
A telescope above the blur of the atmosphere.
Someone has been living in orbit ever since.
Found that ancient Mars could have supported microbial life.
The first close look at Pluto and its icy heart.
The first orbital-class booster to land upright — reusable launchers begin.
The shadow of M87*, 55 million light-years away.
An infrared telescope seeing the first galaxies.
The first test of deflecting an asteroid — it shortened Dimorphos's orbit.
Cassini–Huygens
Swinging close behind a moving planet, a spacecraft is bent by its gravity and dragged along — leaving faster than it arrived, without burning fuel. The planet slows by an immeasurably tiny amount.
Closer passes bend the path more. Relative to Jupiter the speed never changes — only the direction does. Relative to the Sun, that new direction adds Jupiter's motion.
Drag to turn it, scroll the view to zoom. Select a system to see what it does.
The real positions of the brightest stars, the planets and the Moon above any place on Earth. Lie on your back with your head to the north — this is what you would see.
Orion
Eclipses, meteor showers, bright planets and spacecraft arrivals over the next year and a half.
Aurora chance: High latitudes only — northern Scandinavia, Iceland, Alaska, southern New Zealand.
You.
One human, about 1.7 metres tall.
After all that distance…
We are still here.