Alex Marshall
@alxm.me
Visual artist, humanist, and creator of things. Science and engineering educated in California, raised in Europe. Based in London, UK.
Creator of Stellata: https://stellata.xyz
Other stuff, including artwork: https://alxm.me
Creator of Stellata: https://stellata.xyz
Other stuff, including artwork: https://alxm.me
8/8 So that's how you know which way is "up"! And if you want to define your own up, you can always enable the REF flag, which allows you to set your own reference datum. Try it yourself, and find an orientation that you want around the Moon: stellata.xyz/v/BIXAgSUHlX...
Stellata — Explore the Universe in 3D
A 3D model of the real universe in your browser: planets, stars, dust and galaxies in true colour, exactly as your eyes would see them. Nothing invented.
stellata.xyz
September 3, 2026 at 1:17 PM
8/8 So that's how you know which way is "up"! And if you want to define your own up, you can always enable the REF flag, which allows you to set your own reference datum. Try it yourself, and find an orientation that you want around the Moon: stellata.xyz/v/BIXAgSUHlX...
7/8 Lastly, the galactic plane is aligned to the Milky Way's orientation. The 0 latitude plane is coincident with the galactic disc, and 0 longitude points to the centre of our galaxy. Coordinate spheres suit the needs of the context and help you know which way you're pointing.
September 3, 2026 at 1:17 PM
7/8 Lastly, the galactic plane is aligned to the Milky Way's orientation. The 0 latitude plane is coincident with the galactic disc, and 0 longitude points to the centre of our galaxy. Coordinate spheres suit the needs of the context and help you know which way you're pointing.
6/8 The ecliptic is the plane that the sun traces through our sky. The planets' orbits are roughly aligned to this datum; it's a useful plane to orient on in our Solar System. 0 longitude is aligned with Earth's vernal equinox where the ecliptic and equatorial planes intersect.
September 3, 2026 at 1:17 PM
6/8 The ecliptic is the plane that the sun traces through our sky. The planets' orbits are roughly aligned to this datum; it's a useful plane to orient on in our Solar System. 0 longitude is aligned with Earth's vernal equinox where the ecliptic and equatorial planes intersect.
5/8 Orbital is available for any object (planet, moon, or star) with an orbit. 0 latitude is coincident with the orbital plane, and 0 longitude always orients towards the object being orbited. This is the only mode where the AI moves in sync with the object's current position.
September 3, 2026 at 1:17 PM
5/8 Orbital is available for any object (planet, moon, or star) with an orbit. 0 latitude is coincident with the orbital plane, and 0 longitude always orients towards the object being orbited. This is the only mode where the AI moves in sync with the object's current position.
4/8 Stellata covers such a wide range of domains that a few different reference plains are available: equatorial, orbital, ecliptic and galactic. Equatorial is Earth-only and the 0 latitude is referenced to the equator's plane. This makes it easy to orient around and near Earth.
September 3, 2026 at 1:17 PM
4/8 Stellata covers such a wide range of domains that a few different reference plains are available: equatorial, orbital, ecliptic and galactic. Equatorial is Earth-only and the 0 latitude is referenced to the equator's plane. This makes it easy to orient around and near Earth.
3/8 In orbit, the (0,0) reference on the AI is the desired orbital path. This is why this is so clearly marked on Apollo's FDAI with extra clarity on the 0 longitudinal marker. In transit between orbits (0,0) is re-oriented to the desired course so the crew can stay on track.
September 3, 2026 at 1:17 PM
3/8 In orbit, the (0,0) reference on the AI is the desired orbital path. This is why this is so clearly marked on Apollo's FDAI with extra clarity on the 0 longitudinal marker. In transit between orbits (0,0) is re-oriented to the desired course so the crew can stay on track.
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.)
September 3, 2026 at 1:17 PM
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.)
8/8 So that's how you know which way is "up"! And if you want to define your own up, you can always enable the REF flag, which allows you to set your own reference datum.
Try it yourself, and find an orientation that you want around the Moon: stellata.xyz/v/BIXAgSUHlX...
Try it yourself, and find an orientation that you want around the Moon: stellata.xyz/v/BIXAgSUHlX...
Stellata — Explore the Universe in 3D
A 3D model of the real universe in your browser: planets, stars, dust and galaxies in true colour, exactly as your eyes would see them. Nothing invented.
stellata.xyz
September 3, 2026 at 1:10 PM
8/8 So that's how you know which way is "up"! And if you want to define your own up, you can always enable the REF flag, which allows you to set your own reference datum.
Try it yourself, and find an orientation that you want around the Moon: stellata.xyz/v/BIXAgSUHlX...
Try it yourself, and find an orientation that you want around the Moon: stellata.xyz/v/BIXAgSUHlX...
7/8 Lastly, the galactic plane is aligned to the Milky Way's orientation. The 0 latitude plane is coincident with the galactic disc, and 0 longitude points to the centre of our galaxy.
Coordinate spheres suit the needs of the context and help you know which way you're pointing.
Coordinate spheres suit the needs of the context and help you know which way you're pointing.
September 3, 2026 at 1:10 PM
7/8 Lastly, the galactic plane is aligned to the Milky Way's orientation. The 0 latitude plane is coincident with the galactic disc, and 0 longitude points to the centre of our galaxy.
Coordinate spheres suit the needs of the context and help you know which way you're pointing.
Coordinate spheres suit the needs of the context and help you know which way you're pointing.
6/8 The ecliptic is the plane that the sun traces through our sky. The planets' orbits are roughly aligned to this datum; it's a useful plane to orient on in our Solar System. 0 longitude is aligned with Earth's vernal equinox where the ecliptic and equatorial planes intersect.
September 3, 2026 at 1:10 PM
6/8 The ecliptic is the plane that the sun traces through our sky. The planets' orbits are roughly aligned to this datum; it's a useful plane to orient on in our Solar System. 0 longitude is aligned with Earth's vernal equinox where the ecliptic and equatorial planes intersect.
5/8 Orbital is available for any object (planet, moon, or star) with an orbit. 0 latitude is coincident with the orbital plane, and 0 longitude always orients towards the object being orbited. This is the only mode where the AI moves in sync with the object's current position.
September 3, 2026 at 1:10 PM
5/8 Orbital is available for any object (planet, moon, or star) with an orbit. 0 latitude is coincident with the orbital plane, and 0 longitude always orients towards the object being orbited. This is the only mode where the AI moves in sync with the object's current position.
4/8 Stellata covers such a wide range of domains that a few different reference plains are available: equatorial, orbital, ecliptic and galactic.
Equatorial is Earth-only and the 0 latitude is referenced to the equator's plane. This makes it easy to orient around and near Earth.
Equatorial is Earth-only and the 0 latitude is referenced to the equator's plane. This makes it easy to orient around and near Earth.
September 3, 2026 at 1:10 PM
4/8 Stellata covers such a wide range of domains that a few different reference plains are available: equatorial, orbital, ecliptic and galactic.
Equatorial is Earth-only and the 0 latitude is referenced to the equator's plane. This makes it easy to orient around and near Earth.
Equatorial is Earth-only and the 0 latitude is referenced to the equator's plane. This makes it easy to orient around and near Earth.
3/8 In orbit, the (0,0) reference on the AI is the desired orbital path. This is why this is so clearly marked on Apollo's FDAI with extra clarity on the 0 longitudinal marker.
In transit between orbits (0,0) is re-oriented to the desired course so the crew can stay on track.
In transit between orbits (0,0) is re-oriented to the desired course so the crew can stay on track.
September 3, 2026 at 1:10 PM
3/8 In orbit, the (0,0) reference on the AI is the desired orbital path. This is why this is so clearly marked on Apollo's FDAI with extra clarity on the 0 longitudinal marker.
In transit between orbits (0,0) is re-oriented to the desired course so the crew can stay on track.
In transit between orbits (0,0) is re-oriented to the desired course so the crew can stay on track.
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.
September 3, 2026 at 1:10 PM
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.
View the scene for yourself here: stellata.xyz/v/BI2AgQUHPt...
The camera is paused at the start of the eclipse: use the arrow keys to scrub time or the UI controls at bottom right.
The camera is paused at the start of the eclipse: use the arrow keys to scrub time or the UI controls at bottom right.
Stellata — Explore the Universe in 3D
A 3D model of the real universe in your browser: planets, stars, dust and galaxies in true colour, exactly as your eyes would see them. Nothing invented.
stellata.xyz
August 22, 2026 at 11:20 AM
View the scene for yourself here: stellata.xyz/v/BI2AgQUHPt...
The camera is paused at the start of the eclipse: use the arrow keys to scrub time or the UI controls at bottom right.
The camera is paused at the start of the eclipse: use the arrow keys to scrub time or the UI controls at bottom right.
Stellata's HDR lighting model is perceptual: it automatically adapts to what your eye would actually see. Note the background stars that appear at the peak of the eclipse and the burst of brightness at the exact angle that the Moon's regolith reflects the Sun's light directly back to the camera.
August 22, 2026 at 11:20 AM
Stellata's HDR lighting model is perceptual: it automatically adapts to what your eye would actually see. Note the background stars that appear at the peak of the eclipse and the burst of brightness at the exact angle that the Moon's regolith reflects the Sun's light directly back to the camera.
...followed by absorption dominated by ozone as sunlight is filtered through the upper atmosphere, then the much darker umbra, the true shadow of Earth. The deep red colour you see is sunlight refracted through the atmosphere: the light of every sunset on Earth simultaneously.
August 22, 2026 at 11:20 AM
...followed by absorption dominated by ozone as sunlight is filtered through the upper atmosphere, then the much darker umbra, the true shadow of Earth. The deep red colour you see is sunlight refracted through the atmosphere: the light of every sunset on Earth simultaneously.
...just right to produce another eclipse event. Next week's partial eclipse is most easily visible from the Americas.
Note the colour changes as different components in Earth's atmosphere influence light absorption at different frequencies. The penumbra starts imperceptibly around 1.25am UTC...
Note the colour changes as different components in Earth's atmosphere influence light absorption at different frequencies. The penumbra starts imperceptibly around 1.25am UTC...
August 22, 2026 at 11:20 AM
...just right to produce another eclipse event. Next week's partial eclipse is most easily visible from the Americas.
Note the colour changes as different components in Earth's atmosphere influence light absorption at different frequencies. The penumbra starts imperceptibly around 1.25am UTC...
Note the colour changes as different components in Earth's atmosphere influence light absorption at different frequencies. The penumbra starts imperceptibly around 1.25am UTC...
See this view for yourself in Stellata: stellata.xyz/v/BI2AgQQH5-...
You can change the model clock by hitting 'T' or clicking on the time at bottom right.
You can change the model clock by hitting 'T' or clicking on the time at bottom right.
Stellata — Explore the Universe in 3D
A 3D model of the real universe in your browser: planets, stars, dust and galaxies in true colour, exactly as your eyes would see them. Nothing invented.
stellata.xyz
August 21, 2026 at 4:54 PM
See this view for yourself in Stellata: stellata.xyz/v/BI2AgQQH5-...
You can change the model clock by hitting 'T' or clicking on the time at bottom right.
You can change the model clock by hitting 'T' or clicking on the time at bottom right.
... the pipeline itself, but I need to get to a common baseline across browsers regardless. WebGL on Chrome translates through ANGLE, whereas Safari on macOS goes straight to Metal, which makes a massive difference. Turns out _almost_ native is a pretty big compromise.
August 20, 2026 at 3:39 PM
... the pipeline itself, but I need to get to a common baseline across browsers regardless. WebGL on Chrome translates through ANGLE, whereas Safari on macOS goes straight to Metal, which makes a massive difference. Turns out _almost_ native is a pretty big compromise.
This is a view that shows (mostly) the side of the Moon that faces away from Earth.
August 18, 2026 at 11:31 AM
This is a view that shows (mostly) the side of the Moon that faces away from Earth.