About FlatAtlas
Updated
FlatAtlas is a free 3D flat Earth map and simulator, launched in October 2026. It places the Sun, the Moon and the planets at the heights published by flat-Earth authors, above Alexander Gleason’s 1892 map, and shows next to them where astronomy puts the same bodies for your place and time. You compare both with the real sky and make up your own mind.
How FlatAtlas calculates
- The real sky. Positions of the Sun, the Moon and the planets come from Astronomy Engine, with parallax and standard refraction, so you can check them against any almanac.
- The flat map. A north-polar azimuthal equidistant projection, 40,000 km across, as on Gleason’s map. Each body stands above the point on Earth where it is directly overhead.
- The flat Earth models. Only the heights set by each model change; FlatAtlas never moves the bodies. The angle at which you would see a body is the arctangent of its height divided by its distance from you across the flat map.
- Each model’s own explanation. Where a model explains something the geometry alone does not, such as sunset by perspective or the unchanged size of the Sun by magnification, FlatAtlas states that explanation with its source.
Sources
- The Flat Earth Wiki (Flat Earth Society): Sun and Moon about 3,000 miles up and 32 miles across.
- Samuel Rowbotham, Zetetic Astronomy (1881 edition): Sun under 700 miles up, the perspective rule for sunset.
- Gleason’s New Standard Map of the World (1892), Leventhal Map & Education Center.
- Astronomy Engine by Don Cross, for the real positions.
Neutrality
Astronomy and geodesy describe the Earth as a slightly flattened sphere about 12,742 km across, with the Sun about 150 million km away; FlatAtlas states this as a fact with its source, the same way it states each flat-Earth claim. FlatAtlas describes each model with its author’s name, its published figures and its own explanations, and shows the astronomical prediction for the same moment. It does not declare a winner and does not mock anyone. The point is the comparison you can make yourself, outside, with the real sky.
Corrections
If a figure, a source or a calculation is wrong, or a model is described in a way its authors would not recognise, write to support@flatatlas.app. Corrections are made on the page and the date at the top is updated.
Free and Pro
The 3D map with the Sun and the Moon, “Check it in the sky”, the height models, the map layers, the guides and the calculator are free. FlatAtlas Pro adds astronomy features: every planet, the sky dome, the realistic Earth surface, a time machine and saved observations. See Pricing.