# Mercator ↔ Equal Earth

> Source: <https://simonwillison.net/2026/Sep/7/equal-earth/>
> Published: 2026-09-07 16:24:16+00:00

**Tool:** [Mercator ↔ Equal Earth](https://tools.simonwillison.net/equal-earth)

I got curious about the Equal Earth map projection that was recently [voted on at the UN](https://www.theguardian.com/world/2026/sep/04/un-vote-world-map-mercator-equal-earth-africa) so I had GPT-6 Astra (medium) in ChatGPT Work [build me](https://chatgpt.com/share/6a9ee520-c82c-83ea-8111-2f7050c08638) this animated transition between Mercator and Equal Earth using D3.

Tags: [geospatial](https://simonwillison.net/tags/geospatial), [d3](https://simonwillison.net/tags/d3), [vibe-coding](https://simonwillison.net/tags/vibe-coding), [gpt-6-astra](https://simonwillison.net/tags/gpt-6-astra)