iiinova — where your digital self keeps evolving

Alex Marshall @alxm.me · 03/09/2026

2/8 the orientation of your spacecraft or aircraft. The question is: relative to what? In an aircraft, the most important thing is knowing where the ground is so that you can safely fly with reference only to instruments. In space, there are many context-dependent choices. (Here's an original FDAI.)

An original Apollo space programme FDAI (Flight Director / Attitude Indicator) shown on its own on a white background.

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Alex Marshall @alxm.me · 03/09/2026

1/8 Which way is up? I replicated the Apollo program's FDAI (Flight Director / Attitude Indicator) instrument to help users orient themselves while exploring in Stellata. An attitude indicator (the other type of AI) tells you… 🔭 #Astronomy #SpaceSky #BuildInPublic #AstroCoding

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Alex Marshall @alxm.me · 22/08/2026

🧵 There's a partial lunar eclipse next week: see the entire ~6 hour event in just over a minute. It's not a coincidence that lunar eclipses follow solar eclipses a few weeks later. The Moon and Earth swap positions, and the alignment is often... 🔭 #Astronomy #SpaceSky #BuildInPublic #AstroCoding

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Alex Marshall @alxm.me · 21/08/2026

One month of lunar rotation in 2.5min (model clock sped up to 4.6hr/sec), with a guest appearance from Earth in early September. And what's up with that shadow in the middle? That's the next partial lunar eclipse happening next week on 28 August... 🔭 #Astronomy #SpaceSky #BuildInPublic #AstroCoding

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Alex Marshall @alxm.me · 18/08/2026

The 🌕 has some pretty wild craters on it! This shows the maps that are stored to render surface lighting for any ray direction. Red is the horizon map, shown summed for all directions simultaneously, and blue is the normal surface deviation map. 🔭 #Astronomy #SpaceSky #BuildInPublic #AstroCoding

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Alex Marshall @alxm.me · 17/08/2026

It turns out that rendering bumpy surfaces is tricky! This is the same view as yesterday's post, but notice that the terminator detail looks different. It's the same underlying photographic texture, but can you tell what I improved? Solution in 🧵👇 🔭 #Astronomy #SpaceSky #BuildInPublic #AstroCoding

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Alex Marshall @alxm.me · 17/08/2026

This is not a photograph, but it is the same moment that the famous "Earthrise" photo was captured by the Apollo 8 crew on 24 December, 1968. What you're seeing is a screenshot of an in-browser 3D model of our solar system, the galaxy, and eventually our universe that I'm building. Link in thread →

3D rendered view from space in an app called Stellata with the Earth's moon in the foreground, and the Earth in the distance, captured at exactly the time and orientation of the famous "Earthrise" photograph taken by the Apollo 8 crew that orbited the Moon for the first time in December 1968.

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