Getting started

Use the planet tabs at the top to switch between Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The entire console recolours to each planet's theme. The three buttons below the 3D view switch between Explore, Profile and Quiz modes.

The 3D view

The central sphere represents the planet. Each surrounding transparent shell is one atmospheric layer. Drag your finger (or mouse) to orbit the planet and see it from any angle. Pinch or scroll to zoom. The auto-rotate button (↻) toggles slow spinning; the reset button (☉) returns to the default viewpoint.

When you tap a layer card in Explore mode, that layer brightens in the 3D view and the others fade. This ties the label to the visual location in the atmosphere.

Explore mode

Shows a six-cell statistics panel, a brief planetary introduction, expandable layer cards and notable phenomena. Each layer card reveals altitude, temperature, pressure, composition and a notable fact. The coloured left border matches the 3D sphere colour for that layer.

Profile mode

Shows two scientific charts. The temperature profile plots temperature (horizontal axis) against altitude or pressure (vertical axis). Temperature inversions, where temperature rises with altitude instead of falling, mark boundaries between layers. The coloured background bands correspond to the same layer colours in the 3D view. The composition bar beneath shows what the atmosphere is made of, to scale by percentage.

For gas giants (Jupiter, Saturn, Uranus, Neptune) the vertical axis is pressure in bar on a log scale, because these planets have no solid surface. Depth increases downward (higher pressure). For terrestrial planets (Mercury, Venus, Earth, Mars) the axis is altitude in km above the surface.

Quiz mode

Tests knowledge of the current planet with six questions covering layer names, composition, temperature behaviour, magnetic protection and cross-planet comparisons. Select an answer to see immediate feedback and the correct explanation. When a layer question is answered, the correct layer highlights in the 3D view. Your best score per planet is saved between sessions (requires browser storage).

Key vocabulary

• Troposphere — lowest layer, where weather occurs; temperature usually falls with altitude.
• Stratosphere — above the troposphere; temperature rises with altitude due to ozone absorbing UV.
• Mesosphere — above the stratosphere; temperature falls again; meteors burn up here.
• Thermosphere — very high, very thin; temperature rises sharply due to solar radiation; aurora occurs here.
• Exosphere — outermost region, gas molecules barely interact; gradually merges with outer space.
• Temperature inversion — when temperature increases with altitude rather than decreasing.
• Scale height — the altitude over which pressure drops by a factor of about 2.7; a measure of how fast the atmosphere thins.
• Greenhouse effect — when atmospheric gases trap outgoing heat, raising surface temperature.

Atmospheric layer data is drawn from published mission results, planetary science literature, and NASA/ESA reference documents. The 3D visualisation uses schematic layer thicknesses, not true altitudes, because real atmospheric layers would be invisible at planetary scale. Temperature profiles use data from the sources listed below.

• Earth — US Standard Atmosphere 1976; NOAA/NASA/USAF; Stratospheric ozone profile from WMO.
• Venus — VEGA balloons 1985; Venera descent probes 1970-1982; Pioneer Venus 1978.
• Mars — Viking 1 and 2 landers; Curiosity/InSight meteorology; MAVEN upper atmosphere.
• Mercury — NASA MESSENGER exosphere observations 2008-2015; MASCS spectrometer data.
• Jupiter — Galileo atmospheric probe 1995; Juno mission 2016-present; Voyager 1 and 2.
• Saturn — Cassini CIRS and UVIS instruments 2004-2017; Voyager radio occultations.
• Uranus / Neptune — Voyager 2 radio and UV occultations 1986-1989; Hubble Space Telescope.

Uncertainty note: Gas giant interior compositions and deeper cloud structures are inferred from models; Uranus and Neptune deep atmospheres have not been directly sampled. Mercury's exosphere is variable over its solar day.