{"slug": "mercator-equal-earth", "title": "Mercator ↔ Equal Earth", "summary": "Simon Willison used GPT-6 Astra (medium) in ChatGPT Work to build an animated transition between the Mercator and Equal Earth map projections using D3, after the Equal Earth projection was recently voted on at the UN. The tool is available at tools.simonwillison.net/equal-earth.", "body_md": "**Tool:** [Mercator ↔ Equal Earth](https://tools.simonwillison.net/equal-earth)\n\nI 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.\n\nTags: [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)", "url": "https://wpnews.pro/news/mercator-equal-earth", "canonical_source": "https://simonwillison.net/2026/Sep/7/equal-earth/", "published_at": "2026-09-07 16:24:16+00:00", "updated_at": "2026-09-07 22:00:56.759385+00:00", "lang": "en", "topics": ["generative-ai", "ai-tools"], "entities": ["Simon Willison", "GPT-6 Astra", "ChatGPT Work", "D3", "Equal Earth", "Mercator", "UN"], "alternates": {"html": "https://wpnews.pro/news/mercator-equal-earth", "markdown": "https://wpnews.pro/news/mercator-equal-earth.md", "text": "https://wpnews.pro/news/mercator-equal-earth.txt", "jsonld": "https://wpnews.pro/news/mercator-equal-earth.jsonld"}}