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.

SIZE & SHAPE
- True Size: drag Greenland onto Africa and see how far the Mercator map misleads
- Bigger Than You Think: Africa outsizes the USA, China, India and Europe (without Russia) put together; your country next to others its size
- How round is Earth, really — the spheroid and the relief, exaggerated or not
- Shortest routes, the horizon from any height and how much the curve hides, moving tectonic plates and the Ring of Fire
- Through the Earth: your antipode, and a straight tunnel from London to Sydney through the planet's layers

WATER
- All of Earth's water gathered into one sphere — and the fresh water, and the lakes and rivers
- Ice sheets as slabs over the land
- Sea level: raise the ocean and watch real coastlines flood — or lower it to the last ice age, when Britain was joined to Europe
- How many days all the world's rivers would take to fill Lake Baikal
- Fourteen lakes, each with a ball of its true volume — and the world's rivers and yearly rainfall on the globe

PEOPLE
- Population as columns on the globe
- Half of humanity lives inside a surprisingly small circle
- If everyone lived like Manhattan, Paris or Houston
- Earth at night: city lights from space
- Your share of the planet: your square of land and cube of water, at true size in AR

TIME & SEASONS
- Live Earth with the real day/night line and the Moon's phase
- Why seasons happen: the orbit, the tilt, and the same sunlight spread over more ground
- Day length at every latitude, and why noon isn't at 12:00
- Time zones and how far they are from the Sun

Every figure is traceable: tap ⓘ in any scene for its sources (NASA, NOAA, USGS, UN, Natural Earth and others).

Four scenes are free, one per chapter. A single one-time purchase opens the other eighteen and AR in every scene. No subscription, no ads, no account, no tracking — the only thing that goes online is the purchase.

In 14 languages. Metric or imperial units. iPhone, iPhone Duo and iPad.