Terra

Earth, to scale.

Terra shows facts about our planet the way they really are: on an interactive 3D globe, at true proportions, with real data behind every number. Put any scene in your room with AR at a scale you choose.

Download on the App StoreFour scenes free, no account
All of Earth’s water gathered into one ball 860 miles across, sitting on the globe

Chapter 1 · True Size

Greenland is not the size of Africa.

The Mercator map stretches everything near the poles. Drag Greenland down to the equator and it shrinks to what it is: smaller than DR Congo. Then put the USA, China, India and Europe inside Africa and see that there is room to spare.

Greenland dragged onto central Africa, covering less than DR Congo
838,000 mi²Greenland. DR Congo is 7% bigger.
The outlines of the USA, China, India and Europe fitted inside Africa
11.5M vs 10.8M mi²Africa against the four of them together.

22 scenes in four chapters

One globe, and a new question every time you turn it.

A cutaway of the Earth with a straight tunnel from London to Sydney through its layers
Chapter 1

Size & Shape

  • True Size
  • Bigger Than You Think
  • How Round Is It
  • Shrink the Earth
  • Shortest Routes
  • How Far Can You See
  • Moving Plates
  • Through the Earth
Europe with the sea raised by 23 feet and the flooded coast marked
Chapter 2

Water

  • All the Water
  • Ice
  • Sea Level
  • Lakes
  • Rain and Rivers
Population drawn as columns rising from India, with Delhi and Dhaka labelled
Chapter 3

People

  • Population Columns
  • Half of Humanity
  • If Everyone Lived Like…
  • Night Lights
  • Your Share of the Planet
The Earth’s orbit seen from above with the solstices and equinoxes marked
Chapter 4

Time & Seasons

  • Live Earth
  • Why Seasons
  • Day Length
  • Time Zones
A cutaway Earth standing on a wooden table in AR, with its core and mantle labelled

AR

Stand the planet on your table.

Every scene can leave the screen. Pick a scale, put the Earth in your room and walk around it: the tunnel through its layers, the ball of all its water, your own square of land at true size.

  • Earth = a 30 cm ball
  • Earth = 1 m across

Sources

Every number has a source.

Tap ⓘ in any scene and see where its figures come from. The data ships with the app, so every scene works offline, and the full list of datasets and licences is in Settings.

  • NASAImagery, night lights
  • NOAARelief and sea floor
  • USGSWater volumes
  • UNCountry populations
  • JRCPopulation grid
  • Natural EarthBorders and coasts

Price

Start free. Pay once for the rest.

One scene in every chapter is free. A single purchase opens all 22 and AR in every one of them. No subscription, no account, no analytics.

  • iPhone and iPad
  • 14 languages
  • Metric or imperial
  • Works offline
FreeFour scenes, one per chapter$0
Full versionAll 22 scenes and AR, pay once. US price.$6.99
Download on the App Store