ORBITAL/ATLAS العربية

A scroll-driven voyage · 0 → 4.5 billion km

THE
PLANETARY
SYSTEM

Eight planets. One star. Trillions of wandering rocks and frozen worlds. Scroll to fall outward from the Sun — every world below is rendered live, from math, in your browser.

8planets
99.86%of all mass
is the Sun
4.568 Gyrof history
~2,100km/h peak winds
on Neptune
Begin the fall

00 · THE STAR

Sun

A G-type main-sequence star holding the entire system together with its gravity.

Diameter
1.3927 M km
Share of system mass
99.86 %
Core temperature
15.7 M °C
Surface temperature
5,505 °C
Age
4.6 Gyr
Light travel to Earth
8 min 20 s

Every second, the Sun fuses roughly 600 million tonnes of hydrogen into helium, converting 4 million tonnes of matter directly into energy. That energy takes over 100,000 years to random-walk from the core to the surface — then just 8 minutes to reach your eyes.

1.3 million Earths could fit inside the Sun.

01 · THE SWIFT PLANET

Mercury

The smallest planet — a cratered iron heart wrapped in a whisper of rock.

Distance from Sun
57.9 M km · 0.39 AU
Diameter
4,879 km
Orbital period
88 days
Day length
59 Earth days
Moons
0
Temperature
−173 → 427 °C

Mercury is locked in a 3:2 spin–orbit resonance: it rotates exactly three times for every two trips around the Sun, so a single solar day there lasts 176 Earth days. Despite the scorching dayside, permanently shadowed polar craters harbor water ice.

Mercury is shrinking — its cooling iron core has contracted the planet by ~7 km, wrinkling the crust into cliffs called lobate scarps.

02 · THE MORNING STAR

Venus

A runaway greenhouse turned Earth’s twin into the hottest world in the system.

Distance from Sun
108.2 M km · 0.72 AU
Diameter
12,104 km
Orbital period
225 days
Day length
243 days · retrograde
Moons
0
Surface temperature
465 °C

Venus spins backwards — and so slowly that its day outlasts its year. Beneath sulfuric-acid clouds, CO₂ at 92 atmospheres of pressure traps heat fiercely enough to melt lead. It is the brightest natural object in our sky after the Moon.

On Venus, the Sun rises in the west and sets in the east.

03 · THE BLUE MARBLE

Earth

The only world known to harbor life — a pale blue oasis in an enormous dark.

Distance from Sun
149.6 M km · 1.00 AU
Diameter
12,742 km
Orbital period
365.25 days
Day length
23 h 56 m
Moons
1
Mean temperature
15 °C

Liquid water covers 71% of the surface. A magnetic field deflects the solar wind; an oxygen-rich atmosphere shields and breathes; a large Moon steadies the axial tilt. Earth sits squarely in the narrow habitable zone where water can persist as a liquid.

Earth is the densest planet in the system — 5.51 g/cm³.

04 · THE RED PLANET

Mars

A cold desert that once ran with rivers — and the most explored world beyond Earth.

Distance from Sun
227.9 M km · 1.52 AU
Diameter
6,779 km
Orbital period
687 days
Day length
24 h 37 m
Moons
2 · Phobos & Deimos
Mean temperature
−63 °C

Olympus Mons, ~22 km high, is the tallest volcano known — nearly three Everests. Valles Marineris stretches 4,000 km, a canyon that would span the United States. Dried deltas and lakebeds show Mars was once warm and wet; rovers now hunt for traces of ancient life.

Phobos is spiraling inward and will either crash into Mars or shatter into a ring within ~50 million years.

INTERLUDE · THE GREAT DIVIDE

Asteroid Belt

Millions of rocky leftovers between Mars and Jupiter — a planet that never formed.

Span
2.2 → 3.2 AU
Largest body
Ceres · 940 km (dwarf planet)
Total mass
≈ 3 % of the Moon
Estimated asteroids
> 1.3 million (>1 km)

Jupiter’s gravity stirred this region so violently that the debris could never assemble into a planet. Kirkwood gaps — empty lanes you can see in the belt — mark orbits that resonate with Jupiter and get flung clear. The 1,600 tumbling rocks drifting past your view are drawn live, each with its own orbit.

Despite the movies, the belt is mostly empty space — spacecraft pass through it without ever seeing a rock up close.

05 · THE GIANT

Jupiter

Two and a half times the mass of every other planet combined — a failed star.

Distance from Sun
778.5 M km · 5.20 AU
Diameter
139,820 km
Orbital period
11.86 years
Day length
9 h 56 m · fastest
Moons
95 confirmed
Cloud-top temperature
−110 °C

The Great Red Spot is an anticyclone wider than Earth that has raged for at least 190 years. Jupiter’s magnetosphere is the largest structure in the system, and its gravity shields the inner planets by deflecting comets. Its moon Europa hides a global ocean beneath the ice.

Jupiter spins so fast that it bulges — its equator is 9,275 km wider than its poles.

06 · THE RINGED JEWEL

Saturn

Its rings span 280,000 km — yet in places they are only about ten metres thick.

Distance from Sun
1.43 B km · 9.54 AU
Diameter
116,460 km
Orbital period
29.4 years
Day length
10 h 42 m
Moons
146 confirmed
Mean density
0.687 g/cm³

The rings are 99% water ice, sculpted by shepherd moons into thousands of ringlets with gaps like the Cassini Division. Moon Titan has a nitrogen atmosphere thicker than Earth’s and lakes of liquid methane. At Saturn’s north pole, a bizarre hexagonal jet stream wider than two Earths has persisted for decades.

Saturn is the only planet less dense than water — in a big enough ocean, it would float.

07 · THE SIDEWAYS PLANET

Uranus

Knocked onto its side by an ancient collision, it rolls around the Sun like a barrel.

Distance from Sun
2.87 B km · 19.2 AU
Diameter
50,724 km
Orbital period
84 years
Day length
17 h 14 m · retrograde
Moons
28 confirmed
Atmosphere temperature
−224 °C · coldest

Uranus is tilted 97.8°, so each pole gets 21 years of sunlight followed by 21 years of darkness. Methane high in the atmosphere absorbs red light, giving the planet its pale cyan glow. Its 13 faint rings orbit vertically, like a ferris wheel around a rolling world.

All 28 moons are named after characters from Shakespeare and Alexander Pope — Titania, Oberon, Ariel, Umbriel…

08 · THE WINDY WORLD

Neptune

The most distant planet — found with a pencil before a telescope.

Distance from Sun
4.50 B km · 30.1 AU
Diameter
49,244 km
Orbital period
164.8 years
Day length
16 h 6 m
Moons
16 confirmed
Peak wind speed
~2,100 km/h

Neptune was predicted mathematically from wobbles in Uranus’ orbit by Adams and Le Verrier, then spotted in 1846. Its supersonic winds are the fastest in the system. Moon Triton orbits backwards — a captured Kuiper Belt object with geysers of nitrogen ice.

Neptune radiates 2.6× more heat than it receives from the Sun. It has completed just one orbit since its discovery.

EDGE · THE FROZEN FRONTIER

Kuiper Belt

A vast ring of frozen worlds beyond Neptune — the system’s deep freezer.

Span
30 → 55 AU
Dwarf planets
Pluto · Eris · Haumea · Makemake
Known objects
> 2,000 (millions estimated)
Famous visitor
New Horizons · 2015 / 2019

Short-period comets are born here. Pluto — smaller than our Moon, with a nitrogen glacier the size of Texas — is just the closest citizen of this realm. In 2019, New Horizons flew past Arrokoth, a pristine 4.5-billion-year-old contact binary: the most distant object ever visited. The 1,200 icy bodies glinting around you are rendered live.

Light from the Sun takes 4+ hours to reach the Kuiper Belt. From here, the Sun is merely the brightest star.

PERSPECTIVE · TRUE RELATIVE DIAMETERS

A Question of Scale

Every circle below is drawn at true relative size. The Sun is cropped — at this scale it would not fit on your screen. You could line up 109 Earths across its face.

Now imagine distance: if the Sun were a 60 cm beach ball, Earth would be a pea 65 metres away, Jupiter a grapefruit at 335 m — and Neptune a marble 1.8 kilometres down the road. Space is mostly… space.