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Eight planets, one dwarf planet and the belt of rubble between them — in the order they go round the sun. Every picture here is drawn from the real thing: real features at their real coordinates, real sizes against each other, and for Saturn the ring opening solved for today rather than assumed.
Below: every planet in orbital order, with the asteroid belt where it actually sits — between Mars and Jupiter — and Pluto at the end, labelled for what it is. Each one links to its own page, where that world is drawn turning on its axis with its moons going round it.
Watch them all move — the solar system simulator → The inner planets The outer planets Launch windows
Planet · 1st from the sun
The smallest planet, the fastest, and the one with almost no sky.
Mercury is the smallest planet and the closest to the sun: 4,879 km across, which makes it smaller than Ganymede and smaller than Titan, both of which are moons. It is mostly iron. The core takes up about 85% of the radius, a proportion nothing else here comes close to, and the leading explanation is that a young Mercury lost most of its rock in a collision.
It goes round the sun in 88 days and turns exactly three times for every two of those orbits, so a day from one sunrise to the next lasts 176 Earth days — two of its years. With almost no atmosphere to move heat around, the ground reaches about 430 °C in that long noon and falls to −180 °C at night. Radar and MESSENGER found water ice in craters at the poles that the sun has never reached.
Planet · 2nd from the sun
Earth's twin in size and mass, and in nothing else at all.
Venus is very nearly Earth's size — 12,104 km across against Earth's 12,742 — and is the least Earth-like place in the solar system. The atmosphere is carbon dioxide at 92 times Earth's surface pressure, the equivalent of being 900 m underwater, and it holds the surface at about 465 °C everywhere: at the poles, at the equator, and right through the night. That is hotter than Mercury, which is twice as close to the sun.
It also turns backwards, and slowly: one rotation takes 243 Earth days while one orbit takes 225, so Venus's day is longer than its year. The cloud deck is sulfuric acid and completely unbroken, which is why no telescope has ever seen the ground through it in visible light and why the globe here is drawn blank. Everything known about the surface underneath comes from radar and from a handful of Soviet landers that survived minutes.
Planet · 3rd from the sun
The only planet where the interesting question is not geology.
Earth is the only place known where water sits liquid on the surface, and the only place known with life. It is the largest and densest of the four rocky planets, the only one with plate tectonics running today, and the only one with a large moon — Ganymede and Titan are bigger than our moon, but they orbit planets hundreds of times heavier than the worlds they circle.
That moon is a quarter of Earth's width, which makes the pair closer to a double planet than anything else in the inner solar system, and it holds the tilt of Earth's axis steady at about 23.4°. The tilt is what gives the year seasons; without the moon it would wander, and the climate with it. The oceans' tides are the moon's doing too, and the drag of them is pushing it about 3.8 cm further away every year.
Planet · 4th from the sun
The planet we have looked at hardest, and still cannot answer the main question about.
Mars is half Earth's width and about a tenth of its mass, with a day of 24 hours 37 minutes and a tilt of 25° — so it has seasons that run on a two-year calendar. The atmosphere is carbon dioxide at about 0.6% of Earth's surface pressure, thin enough that liquid water on the surface boils and freezes at the same time, and thick enough to raise dust storms that can cover the planet for weeks.
It holds the extremes of the solar system's geography: Olympus Mons stands about 22 km high, and Valles Marineris runs 4,000 km along the equator, which on Earth would reach from California to New York. Riverbeds, deltas and lake floors are everywhere in the older terrain, so the water was there and stayed long enough to move rock. Where it went, and when, is the question every rover on the ground is there to answer.
Not a planet · between Mars and Jupiter
Not a hazard, not a shattered planet — a place where a planet was never allowed to finish.
Between Mars and Jupiter, from roughly 2.1 to 3.3 times Earth's distance from the sun, is a broad ring of rock and metal that never became a planet. Jupiter is the reason: its gravity stirred the region hard enough that the material there kept colliding at speeds that broke bodies apart rather than building them up. What is left is not the wreckage of an exploded world — the pieces have different compositions and never formed one.
There is far less of it than the pictures suggest. Everything in the belt put together comes to about 3% of the mass of the Moon, and Ceres alone — a dwarf planet 940 km across — is roughly a third of that. The typical gap between two named objects runs to millions of kilometres, which is why every spacecraft sent to the outer planets has flown straight through without steering around anything.
Planet · 5th from the sun
Two and a half times the mass of everything else in the solar system put together.
Jupiter is two and a half times the mass of every other planet, moon, asteroid and comet in the solar system put together. It is hydrogen and helium in roughly the sun's proportions, with no surface at all: the gas simply gets denser with depth until it behaves like a liquid metal. It turns once in under ten hours, faster than anything else here, and that spin visibly squashes it — the equator is about 7% wider than the poles.
The Great Red Spot has been watched for at least 190 years and is still shrinking; it was more than twice Earth's width in the 1800s and is now about one Earth across. Four of its moons are worlds in their own right, and Io, Europa and Ganymede are locked in a resonance that keeps flexing them: Io is the most volcanically active body known, and Europa holds a salt-water ocean under its ice with more water in it than every ocean on Earth.
Planet · 6th from the sun
The rings are the famous part. The moons are where the questions are.
Saturn is the second-largest planet and the least dense object in the solar system — mean density about 0.69 that of water. The rings are its own signature: 280,000 km across and in most places only tens of metres thick, made of water ice from dust grains up to boulders. Drawn to scale they are a sheet of paper the width of a football pitch, which is why they vanish to a line when Earth passes through their plane, as it last did in March 2025.
It has more confirmed moons than every other planet put together, and two of them are among the most interesting places anywhere. Titan is bigger than Mercury and the only moon with a thick atmosphere, with rivers, rain and seas of liquid methane on a surface at −179 °C. Enceladus, 500 km across, sprays water from an ocean under its south pole through cracks in its ice — Cassini flew through those plumes and tasted salt and organic molecules in them.
The rings are drawn as they stand today, not at a convenient angle: Earth is 9.0° below Saturn’s ring plane, so the rings here are close to edge-on — a narrow ellipse, not the wide oval diagrams always draw. It shifts as the planet goes round the sun, and the picture shifts with it.
Planet · 7th from the sun
Tipped over on its side, visited once, and still mostly unexplained.
Uranus lies on its side. Its axis is tilted 98°, so instead of spinning like a top it rolls along its orbit, and each pole spends 42 years in continuous sunlight followed by 42 years of night. The most likely cause is an impact with something Earth-sized early on, though the moons orbit tidily around the tipped equator, which is hard to arrange with a single blow.
It is the coldest atmosphere measured anywhere in the solar system, −224 °C, colder than Neptune despite being closer to the sun — nobody has fully explained that. In visible light it is nearly featureless, a flat blue-green from methane absorbing red light, and it has been visited exactly once: Voyager 2 flew past in January 1986 and everything since has come from telescopes. Its 13 narrow, dark rings were found in 1977 when they blocked the light of a star.
The rings are drawn as they stand today, not at a convenient angle: Earth is 75.3° above Uranus’s ring plane, so the rings here are drawn as near-circles round the disc: we are looking almost straight down on them. It shifts as the planet goes round the sun, and the picture shifts with it.
Planet · 8th from the sun
Found with a pencil before anyone pointed a telescope at it.
Neptune is the farthest planet, 30 times Earth's distance from the sun, and it was found with mathematics before anyone looked: Uranus was not keeping to its predicted path, and in 1846 Neptune was located within a degree of where the calculations said the missing pull had to come from. One of its years lasts 165 of ours, so it has completed a single orbit since that night.
It has the fastest winds anywhere — measured near 2,000 km/h — on a planet that receives about a thousandth of Earth's sunlight, which means the weather is driven from inside rather than from above. Triton, its big moon, goes round backwards, which means it did not form there: it is a captured Kuiper belt object, and it has nitrogen geysers on a surface at −235 °C.
Dwarf planet · beyond Neptune, in the Kuiper belt
A dwarf planet, a double world, and the only one of these anybody has visited exactly once.
Pluto is a dwarf planet, and the label is a statement about its neighbourhood rather than about the world itself. The IAU's 2006 definition asks a planet to have cleared its orbital region; Pluto shares the Kuiper belt with a great many other bodies, one of which — Eris — turned out to be more massive. It is 2,377 km across, smaller than our moon, and its 248-year orbit is tilted and elliptical enough to bring it inside Neptune's for 20 years at a time.
It is also a double world. Charon is half Pluto's diameter, and the point the two of them orbit lies outside Pluto's surface — nothing else here does that. When New Horizons arrived in July 2015 and turned a fuzzy dot into a place, it found a 1,000 km glacier of nitrogen ice with no craters on it at all, mountains of water ice standing 3 km high, and a hazy blue atmosphere in dozens of layers. It has been visited once, for a single day.
Ten cards down a page put the planets a screen apart, evenly. They are not. Neptune is 78 times further from the sun than Mercury, and the four rocky planets together occupy the innermost tenth of the system — so any picture that shows all of them at once has either squashed the outside or lost the inside. The solar system simulator deals with that by climbing a ladder of views instead of pretending one frame can hold it, and the shape you see at the top of that ladder is the real one.
The same goes for size. Jupiter is 11.0 times Earth's width and Mercury 0.38 of it; one AU — the Earth's own distance from the sun — is 149,597,870 km, which is about 11,741 Earths laid end to end. Every figure on this page comes from the same orbital elements and masses the simulator draws with, not from a table typed beside them.
The belt is not the only thing between the planets. Comets come in on long ellipses from much further out, and launch windows are what it takes to actually reach any of these places — solved from the same orbits, not looked up.
Closer to home: the sun and moon from your own town · Earth and the Moon to scale · tonight's moon phase · sunrise and sunset by city · the classroom guide
How many planets are there? Eight. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Pluto was counted as a ninth from its discovery in 1930 until 2006, when the International Astronomical Union defined a planet as a body that orbits the sun, is round under its own gravity, and has cleared its orbital neighbourhood. Pluto meets the first two and not the third.
Is Pluto a planet? It is a dwarf planet — that is a real category, not a demotion to nothing. It shares the Kuiper belt with a great many other bodies, one of which, Eris, turned out to be more massive than Pluto. That discovery in 2005 is what forced the definition.
What is between Mars and Jupiter? The asteroid belt: rock and metal spread between roughly 2.1 and 3.3 AU that never formed into a planet, because Jupiter's gravity kept stirring it. All of it together comes to about 3% of the mass of the Moon.
Which planet is closest to Earth? On average, Mercury. It is a counter-intuitive answer, and it is right: Venus comes closer than anything else at its nearest, but it also spends long stretches on the far side of the sun, while Mercury never gets far from it. Averaged over time, Mercury is the nearest planet to Earth — and to every other planet.
Can I see them without a telescope? Five of them, yes — Mercury, Venus, Mars, Jupiter and Saturn are all naked-eye objects, and were known as planets thousands of years before telescopes existed. Uranus is borderline under a very dark sky; Neptune needs optics.