Four things to take hold of
The Playground
Everything on this site that moves when you push it, arranged outward to inward — from seven hundred million light years out down to a map you can find your own street on. Nothing here is a video: every frame is drawn while you watch.
01
Our slice of the universe
From Neptune's orbit to the Great Attractor — a factor of about ten to the fifteen, navigable in one continuous move. Andromeda is 2.6 million light years away and closing; everything past it is a real catalogued galaxy.
- Dragturn the view
- Scroll or pinchmove in and out
- Click anythinggo and look at it
- The ladder belowjump between eleven scales
- ⬡draw the geometry — outlines and orbits
- F, then W A S Dfly it yourself
Building the galaxy
The Local Group
Every galaxy gravity still holds onto us with, at its measured distance. The turnable view of all of it needs WebGL 2.
Galaxies of the Local Group
Everything gravity still holds onto us with, at its measured distance.
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Sagittarius Dwarf Sgr dSph
26.0 kpc · dwarf spheroidal · a few hundred million stars
Falling through the disc of the Milky Way and being pulled apart by it. Its stars are strung right round our galaxy in a stream that wraps the sky, and it has been through the disc at least twice.
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Large Magellanic Cloud LMC
50.0 kpc · barred irregular · 20 billion stars
The fourth largest galaxy in the Local Group and the brightest thing in the southern sky that is not in our own. It has one lopsided bar, one arm, and the Tarantula — the most violent star-forming region known anywhere nearby.
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Small Magellanic Cloud SMC
62.4 kpc · dwarf irregular · 3 billion stars
Being drawn out by the Large Cloud and by us — the Magellanic Stream of hydrogen behind both of them is gas that has already been pulled off. Henrietta Leavitt found the period–luminosity law in its Cepheids, which is how anything further than this is measured at all.
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Barnard's Galaxy NGC 6822
459 kpc · dwarf irregular · a few billion stars
A small barred irregular out on its own, no satellite of anything. Hubble used its Cepheids in 1925 to show it lay outside the Milky Way, which was part of settling whether other galaxies existed.
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IC 10 IC 10
794 kpc · dwarf irregular starburst · a few billion stars
The only starburst galaxy in the Local Group, and awkward to observe because it sits three degrees off the plane of the Milky Way and everything we see of it is through our own dust.
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Messier 32 M32
805 kpc · compact elliptical · 3 billion stars
A satellite of Andromeda and the nearest compact elliptical to us. Probably the stripped core of something once much larger that Andromeda has eaten most of.
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Messier 110 NGC 205
824 kpc · dwarf elliptical · 10 billion stars
Andromeda's other bright satellite, and unusually for an elliptical it still has dust and a little recent star formation in its middle.
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Triangulum M33
840 kpc · spiral · 40 billion stars
The third largest galaxy in the Local Group and the furthest thing visible to the naked eye from a properly dark site. No bar, no real bulge, and arms that are flocculent rather than cleanly two-armed.
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Andromeda M31
785 kpc · barred spiral · 1 trillion stars
The big one — half again across as the Milky Way, and closing at a hundred and ten kilometres a second. In about four and a half billion years the two discs will pass through each other and end up as one elliptical. Every star will survive it; almost none will collide.
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Wolf–Lundmark–Melotte WLM
933 kpc · dwarf irregular · a few hundred million stars
Right out at the edge of the Local Group and isolated enough that it has probably never interacted with anything, which makes it a useful control: a galaxy that has been left alone.
Landmarks inside our own galaxy
The clusters and nebulae near enough to have a place in the model rather than a position on a chart.
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Hyades
153 light years · cluster
The nearest open cluster, and the face of Taurus. Six hundred million years old and slowly coming apart.
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Pleiades
444 light years · cluster
Hot blue stars a hundred million years old, ploughing through an unrelated dust cloud that scatters their light back at us.
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Orion Nebula
1344 light years · nebula
The nearest big star factory, and the middle of it is four stars lighting a cavity they have blown in the cloud that made them.
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Rosette Nebula
1.6 kpc · nebula
A cluster in the middle of the flower it has cleared out of the cloud around it.
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North America Nebula
2593 light years · nebula
Hydrogen glowing in Cygnus, with the Gulf of Mexico a dust lane in front of it rather than a hole in the gas.
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Carina Nebula
2.3 kpc · nebula
Far bigger and more violent than Orion, and containing Eta Carinae, which nearly blew itself apart in 1843 and is still there.
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Omega Centauri
5.2 kpc · globular
Ten million stars, and almost certainly not a cluster at all — the stripped nucleus of a dwarf galaxy the Milky Way pulled apart.
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Messier 13
6.8 kpc · globular
The great globular in Hercules, and the target of the 1974 Arecibo message, which will arrive in about twenty-three thousand years.
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Sagittarius A*
8.2 kpc · centre
Four and a third million solar masses inside a horizon about the width of Mercury's orbit. Watching stars whip round it is how the distance to the centre of the galaxy is now measured. Drawn magnified — it would be far smaller than a pixel at true size — but every proportion inside it is real: the shadow is 2.6 times the horizon because that is what the bending produces, and the disc starts at the innermost orbit anything can hold.
The structure above us
The groups, clusters and superclusters our galaxy is a part of, out to the largest thing anybody has named.
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Local Group
400 kpc · group
Us, Andromeda, Triangulum and about eighty dwarfs, most of them faint enough that we are still finding them. Two big spirals falling toward each other and everything else falling toward one or the other.
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M81 Group
3.63 Mpc · group
The nearest group of comparable size to ours. M81 and M82 passed close a few hundred million years ago and the bridge of hydrogen between them is still there — M82 is a starburst because of it.
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Centaurus A Group
3.80 Mpc · group
The nearest giant elliptical, with a dust lane across it from a spiral it swallowed and a jet coming out of the black hole at the middle. The closest active galactic nucleus to Earth.
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Sculptor Group
3.90 Mpc · group
Strung out along a filament rather than bound into a ball — one of the nearest places you can see that galaxies are arranged in threads.
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Canes Venatici I
4.50 Mpc · group
A loose cloud of mostly small, gas-rich galaxies around M94. Barely bound, and probably still collapsing.
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Virgo Cluster
16.50 Mpc · cluster
Thirteen hundred galaxies and the mass at the middle of our supercluster. Everything nearby, us included, is falling toward it at a few hundred kilometres a second. M87 sits at its centre, and the first photograph ever taken of a black hole is of the one inside M87.
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Virgo Supercluster
16.50 Mpc · supercluster
The flattened sheet of a hundred or so galaxy groups that our own Local Group sits at the edge of, about a hundred and ten million light years across and only a fifth of that thick. Virgo is the mass at the middle and everything here, us included, is falling toward it. Its plane is the supergalactic plane, which is why so much of the nearby sky lines up along one great circle.
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Fornax Cluster
19.30 Mpc · cluster
Smaller than Virgo and much tidier — a compact, evolved cluster that is one of the best places to study what happens to a galaxy when it falls into one.
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Local Void
23.00 Mpc · void
Forty-five megaparsecs of almost nothing, starting right next door. The Local Group sits on its edge and is being pushed away from it at about two hundred and sixty kilometres a second — a void repels by having nothing in it to pull back.
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Centaurus Cluster
52.00 Mpc · cluster
Abell 3526, and one of the nearer rich clusters. Two separate groups of galaxies inside it are still moving through each other.
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Laniakea
55.00 Mpc · supercluster
Our supercluster, and a definition rather than a discovery: in 2014 Tully and colleagues mapped the peculiar velocities of a hundred thousand galaxies and drew the boundary where the flows stop converging on us and start converging on something else. Everything inside is falling toward the Great Attractor. It is five hundred million light years across, it contains the Virgo Supercluster as one of four lobes, and we are near its outer edge — which means Laniakea is not bound and will be pulled apart by the expansion long before it ever collapses.
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Hydra Cluster
58.00 Mpc · cluster
Abell 1060 — small, regular, and unusually undisturbed, which makes it a control case for everything the messier clusters do.
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The Great Attractor
65.00 Mpc · attractor
The gravitational focus our whole corner of the universe is drifting toward at six hundred kilometres a second, and it sits almost exactly behind the plane of the Milky Way — which is why it took until the 1980s to notice and why the map is empty in front of it. The Norma Cluster is the part of it we can see.
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Perseus–Pisces
74.00 Mpc · cluster
One of the longest structures known — a chain of clusters running about three hundred million light years, on the far side of the sky from the Great Attractor.
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Coma Cluster
99.00 Mpc · cluster
A thousand large galaxies in a ball, nearly all of them ellipticals that have had their gas stripped. In 1933 Zwicky measured how fast they were moving, found it was far too fast for the visible mass to hold them together, and inferred dark matter from it.
Press Esc to release the mouse
02
Everything we have out there
All 28 working spacecraft beyond Earth, drawn where they actually are today, on a logarithmic map of the solar system.
- Dragturn the system
- Scroll or pinchzoom
- Click a bodymake it the middle
- The row belowgo to a planet
Press Esc to release mouse
The full list of what each one is doing is on the missions page.
03
The sky over your head
Every star down to magnitude 5, where it is right now, from wherever you happen to be standing. Say where that is and the chart turns to match.
- Use my locationor type a coordinate
- The sliderrun the sky forward or back
- Hover a starread its name and height
Say where you are — the panel below, or the button here — and the sky over that spot is drawn.
The rim is your horizon and the middle is straight up; east is on the left, because you are looking up at this rather than down at a map. More of what is overhead, including station passes and tonight's darkness, is on the Overhead page.
04
The ground underneath
161 places where space is a thing that actually happens — pads, observatories, landing zones, craters, and whatever is erupting this week.
- Dragpan the world
- Click into itthen scroll to zoom · Esc to leave
- Click a markerread what it is
- Searcha town, or paste a coordinate
Search for a town or paste a coordinate, or press ◎ for where you are. Coastlines, borders, states and roads sharpen as you go in.
Search an address or press ◎ to put yourself in the middle. The crosshair reads the zone under it, and the detail sharpens four-fold as you go in.
Press Esc to release mouse
The nine zones · Bortle-equivalent, estimated from satellite data
- 1 Pristine Bortle 1–2 · naked eye to mag 7.2–8.0 The Milky Way casts a shadow. Airglow is visible, the zodiacal light reaches across the sky, and the darkest places on Earth look like this.
- 2 Rural Bortle 2–3 · naked eye to mag 6.7–7.5 The Milky Way is structured and obvious. Light domes sit low on the horizon over distant towns, and the rest of the sky is genuinely dark.
- 3 Rural transition Bortle 3–4 · naked eye to mag 6.2–7.0 The Milky Way is clearly there but loses its detail near the horizon. Light domes are obvious in several directions.
- 4 Suburban edge Bortle 4–5 · naked eye to mag 5.7–6.5 The Milky Way is a faint band overhead and gone lower down. The sky is noticeably grey rather than black.
- 5 Suburban Bortle 5–6 · naked eye to mag 5.2–6.0 The Milky Way is invisible or nearly so. Clouds are lit from below. You can read a newspaper outside on a clear night.
- 6 Bright suburban Bortle 6–7 · naked eye to mag 4.7–5.5 The sky within thirty degrees of the horizon glows greyish white. Only the brighter constellations survive.
- 7 Urban Bortle 7–8 · naked eye to mag 4.2–5.0 The whole sky is greyish. Stars beyond the fourth magnitude are gone, and the Pleiades are a smudge if they show at all.
- 8 Inner city Bortle 8–9 · naked eye to mag 4.0–4.5 A few dozen stars, the Moon and the planets. The sky has a colour, and it is not black.
- 9 Core Bortle 9 · naked eye to mag under 4.0 The brightest handful of stars, and nothing else. Orion is recognisable only by its belt.
Zone 1 is not painted: it is nine tenths of the planet, and leaving it clear is what makes the rest readable.
Switch the light-pollution layer on and press ◎ to put your own address in the middle. The whole map, with every place listed underneath it, is on the map page.
What is real here, and what is not
Every position is real. The spacecraft are at their computed distances, the stars are catalogued, and each galaxy is at its measured distance in its measured direction, turned to the angle it actually presents to us.
The Milky Way's own stars are generated — there are two hundred billion and no catalogue of them exists. The shape is its measured shape, with stars put back into it. Nobody has ever photographed the Milky Way from outside.
Outlines are shapes, not walls, and start off. A cluster has no edge; what it has is a measured extent. Laniakea is marked as the exception, because its boundary is a velocity field rather than a surface.
The Sun sits 26.7 thousand light years out, in the Local Arm. The whole of the second figure would fit inside a full stop printed on the first.