This text edition preserves every field-guide feature when WebGL, pointer input, or motion is unavailable. Evidence status distinguishes direct observation, processed imagery, scientific inference, and explanatory illustration.
Central star · G-type main-sequence starSun
The Sun contains almost all the mass in the Solar System. Its visible surface is a turbulent plasma, while ultraviolet observatories reveal loops, active regions, and the million-degree corona above it.
695,700 km mean radius- Active region — Sunspots are cooler than the surrounding photosphere but still intensely hot. Their twisted magnetic fields can store energy later released in flares and coronal mass ejections. (observed)
- Coronal loop — Extreme-ultraviolet wavelengths isolate plasma at different temperatures, revealing bright material constrained by magnetic fields rather than a solid atmospheric structure. (processed)
- Convection zone — Helioseismology uses oscillations at the visible surface to infer motions and boundaries inside the Sun. The convection zone occupies roughly the outer thirty percent by radius. (inferred)
1st planet · Rocky worldMercury
MESSENGER revealed a cratered planet with enormous impact basins, long contractional cliffs, polar ice in permanent shadow, and an iron core unusually large for its size.
2,439.7 km mean radius- Caloris Basin — The Caloris impact excavated a vast multi-ring basin. Later volcanic plains flooded parts of the floor, while jumbled terrain formed near the antipode. (observed)
- Polar cold traps — MESSENGER measurements support water ice and dark organic-rich material in permanently shadowed northern polar craters despite Mercury's proximity to the Sun. (inferred)
- MESSENGER orbit — MESSENGER measured composition, topography, gravity, magnetic field, and exosphere before ending with a planned surface impact. (observed)
2nd planet · Cloud-covered rocky worldVenus
Venus hides beneath sulfuric-acid clouds. Radar mapping reveals volcanic plains, tessera highlands, and great shield volcanoes beneath an atmosphere hot enough to melt lead at the surface.
6,051.8 km mean radius- Maat Mons — Magellan radar images reveal lava flows and a complex summit. Changes between radar observations have been interpreted as possible evidence of recent volcanic activity. (inferred)
- Maxwell Montes — Maxwell Montes stands within Ishtar Terra. Radar-bright high elevations may be coated by minerals stable only in the cooler conditions found at altitude. (processed)
- Venera 13 — Venera 13 survived for 127 minutes under about ninety times Earth's sea-level pressure, analysing basaltic soil and transmitting panoramic images. (observed)
3rd planet · Ocean worldEarth
Earth's visible surface is a changing combination of rock, water, ice, clouds, and life. Satellite composites make global patterns legible while night imagery reveals the uneven geography of human settlement.
6,371 km mean radius- Himalaya — The Indian plate continues to converge with Eurasia, thickening the crust and raising the Himalaya. Mount Everest reaches 8,849 metres above sea level. (observed)
- Mariana Trench — At Challenger Deep, the Pacific plate bends and descends beneath the Mariana plate. Pressure exceeds one thousand times that at sea level. (observed)
- Nile at night — Black Marble composites show settlement concentrated along the Nile and its delta, making water and population geography visible from orbit. (processed)
Earth's satellite · Airless rocky worldMoon
The Moon's craters, dark basaltic maria, bright highlands, and enormous far-side basin record the early Solar System. LRO imagery and laser altimetry turn that record into a measurable globe.
1,737.4 km mean radius- Apollo 11 — Neil Armstrong and Buzz Aldrin landed Eagle after taking partial manual control beyond a boulder field. Their surface stay returned samples and direct observations from a basaltic plain. (observed)
- Chandrayaan-3 — The lander and Pragyan rover measured the local plasma and thermal environment and confirmed several elements in the regolith at high southern latitude. (observed)
- South Pole ice — With almost no direct sunlight, polar cold traps remain cold enough to retain volatile material. Spectral, radar, neutron, and impact observations provide complementary evidence. (inferred)
- Tycho crater — Tycho's sharp rim, central peak, terraced walls, and long ray system make it an unusually legible complex impact crater on the lunar surface. (observed)
4th planet · Cold desert worldMars
Mars preserves channels, deltas, sedimentary rocks, glaciers, lava plains, and the largest volcano in the Solar System. Orbiters and rovers read this archive at scales from global topography to mineral grains.
3,389.5 km mean radius- Olympus Mons — Olympus Mons is a broad shield volcano built by repeated low-viscosity lava flows. Its gentle flanks end in a high basal escarpment. (observed)
- Jezero crater delta — Perseverance landed in Jezero to investigate layered sedimentary rocks, collect samples, and test whether its ancient environments could have preserved signs of microbial life. (observed)
- Valles Marineris — Tectonic extension opened deep troughs later modified by landslides, erosion, and possible water-related processes. The system dwarfs Earth's Grand Canyon. (observed)
Mars deep-time states
Observed terrain is preserved beneath a constrained reconstruction of water, ice, haze, and atmospheric density.
- Early record — 4.1 billion years ago. The oldest surviving crust records intense impacts and rapid resurfacing on a planet whose global appearance remains difficult to reconstruct. Evidence: Ancient crust, impact record, and global geologic mapping. Constrained reconstruction: Substantial atmosphere and limited topography-guided lowland water. Confidence: Terrain is observed; water extent and atmospheric density are low-confidence hypotheses.
- Valley networks — 3.8 billion years ago. Widespread branching valleys and altered minerals record repeated surface runoff and water-rock interaction across the ancient highlands. Evidence: Mapped valley networks, lake basins, and water-altered minerals. Constrained reconstruction: Peak hydrology signal with a denser modelled atmosphere and hazier limb. Confidence: Landforms are observed; global climate and connected water extent remain model-dependent.
- Lake worlds — 3.5 billion years ago. Deltas, crater lakes, and enormous outflow channels preserve a complex history of standing water, river deposition, and episodic floods. Evidence: Jezero delta and lake deposits, channels, and sedimentary rocks. Constrained reconstruction: Regional lowland water with a declining carbon-dioxide atmosphere. Confidence: Lake and delta evidence is strong; simultaneous global water coverage is not established.
- Drying world — 3 billion years ago. Long-lived surface water became less stable as atmospheric loss, cooling, volcanism, and episodic floods reshaped an increasingly arid planet. Evidence: Younger volcanic plains, outflow channels, and declining resurfacing rates. Constrained reconstruction: Retreating surface water, thinner haze, and increasingly oxidised terrain. Confidence: The transition is well supported, but its absolute timing varies by crater chronology model.
- Ice cycles — 1 billion years ago. A cold desert persisted while orbital cycles repeatedly shifted ice between the poles and middle latitudes. Evidence: Polar layered deposits, glacial landforms, and near-surface ice. Constrained reconstruction: Present-like desert colour with a stronger modelled ice signal. Confidence: Ice migration is supported; this global frame compresses many separate climate cycles.
- Present day — Present day. Modern Mars is a cold, oxidised desert with a thin carbon-dioxide atmosphere, polar caps, buried ice, and only transient brines considered possible. Evidence: Orbital mapping, landers, rovers, and present atmospheric measurements. Constrained reconstruction: No reconstructed surface water; the delivered Viking/MOLA world remains visible. Confidence: Observed and processed present-day products provide the highest-confidence global state.
5th planet · Gas giantJupiter
Jupiter has no solid surface to stand on. Its visible belts and zones are cloud tops shaped by fast rotation, deep atmospheric circulation, chemistry, and storms that can outlive generations of observers.
69,911 km mean radius- Great Red Spot — The Great Red Spot rotates counter-clockwise in Jupiter's southern hemisphere. It is shrinking over long timescales but remains wider than Earth. (observed)
- North polar aurora — Particles accelerated through Jupiter's magnetosphere collide with the upper atmosphere. Volcanic material from Io helps feed the system. (processed)
- Io flux tube — Io's volcanoes supply sulfur and oxygen ions to a plasma torus. Its motion through Jupiter's field creates a current system with auroral footprints. (inferred)
6th planet · Ringed gas giantSaturn
Saturn's muted atmosphere conceals fierce winds and a polar hexagon. Its rings are thin, structured, and temporary on geological timescales, sculpted by resonances and small moons.
58,232 km mean radius- North polar hexagon — The hexagon is a persistent atmospheric wave embedded in an eastward jet. Cassini observed changes in its colour and surrounding haze with Saturn's seasons. (observed)
- Cassini Division — The division is not empty; it contains sparse ring material. Orbital resonances remove particles from some paths and concentrate complex wave patterns elsewhere. (observed)
- Enceladus plume source — Cassini flew through plumes venting from fractures near Enceladus's south pole, sampling salts, organics, silica, and water sourced from a subsurface ocean. (observed)
7th planet · Ice giantUranus
Uranus's blue-green methane haze hides a dynamic atmosphere. Its extreme axial tilt creates decades-long seasons, while its magnetic field is strongly tilted and offset from the planet's centre.
25,362 km mean radius- Extreme seasons — Uranus's rotation axis lies close to its orbital plane. Near solstice, one hemisphere points toward the Sun while the other experiences a long polar night. (observed)
- Epsilon ring — Uranus's rings contain larger, darker particles than Saturn's bright ice-rich rings. The epsilon ring varies in width and is constrained by Cordelia and Ophelia. (observed)
- Offset magnetic axis — Voyager 2 measurements revealed a highly asymmetric magnetosphere. Rotation causes the magnetic tail to twist into a corkscrew-like configuration. (inferred)
8th planet · Ice giantNeptune
Neptune radiates more energy than it receives from the Sun. That internal heat helps drive bright methane-ice clouds, dark vortices, and the fastest measured winds on any planet.
24,622 km mean radius- Great Dark Spot — Unlike Jupiter's long-lived Great Red Spot, Neptune's dark vortices can emerge and dissipate over years. Bright companion clouds form as air rises and condenses methane ice. (observed)
- Supersonic winds — Cloud tracking reveals strong east-west jets. The energy source and momentum transport remain active research questions so far from weak sunlight. (inferred)
- Triton's retrograde orbit — Triton's retrograde, inclined orbit indicates capture from the outer Solar System. Voyager 2 observed young terrain and nitrogen geyser-like plumes. (inferred)