Authors: Dr. Megan, Sean, and Jonathan

Hey folks~

The next batch of updates and fixes is now available for public testing. This includes some future-proofing work for system builders and ship modelers, as well as adjustments made from community Catalog Notes and the addition of the first-of-its-kind exosatellite CD-35 2722 B b. Some of these changes are more involved than simple patch notes can provide, so we've written up extra details for your perusal below.

To opt in to the Beta branch, go to your Steam library, right-click SpaceEngine, then go to Properties> Game Versions & Betas, and select beta (public beta branch) from the list. To report any issues that arise, go to the Troubleshooting and Bug Reports section of the Steam forums, or the #bug-reports channel in our official Discord.

New Spacecraft Material Config Options

Spacecraft material definitions now support two new features: texture gamma correction and green channel inversion for DirectX normal maps.

SpaceEngine expects all input textures and colors to be in linear values (albedo). Most modern PBR textures are authored to this standard, but almost all older/non-PBR textures are not, and need to be converted to linear values for use in SpaceEngine. Otherwise, they will look too light/washed out. SE now supports this via the DiffGamma and EmisGamma parameters for diffuse and emissive textures, respectively. Assigning them a negative number, like -1, will cause sRGB->linear conversion to be used (this is what you want most of the time). Positive values will use a simple fixed power gamma correction, using the provided value as the exponent.

Comparison of textures without and with gamma correction. Note how the solar panels are realistically dark after gamma correction is applied.

For spacecraft normal maps, it's important to ensure they're using the OpenGL standard. DirectX normal maps have an inverted green channel compared to OpenGL, so if you're using a normal map authored for DirectX rendering (which will usually be the case), you need to invert the green channel for it to render correctly in SpaceEngine. SE can now take care of that for you with the new DirectXNormMap parameter, a simple boolean that will invert the green channel of your assigned normal map when set to "true".

Comparison of a DirectX normal map without and with green channel inversion. Note how before conversion, the geometry is illuminated from the upper right while the normals are illuminated from the bottom right. After conversion, the lighting is consistent and correct.

Here are a few examples of how to use the new parameters. Make sure you're working in the correct Material tags for the texture you want to change to avoid any unwanted washout or shadow inversion!

Above: Example of how to use the new parameters in your ship's .sml material config file. DiffGamma will apply the sRGB > linear conversion, EmisGamma will apply a 1.8 power gamma correction, and DirectXNormMap will flip the green values of the assigned normal map.

New Catalog Addition: The First Exosatellite

An object discovered in the CD-35 2722 system by Hoy et al. (2026) has been deemed the first “planetary-mass exosatellite.” The 0.92 Jupiter mass object orbits a 31 Jupiter mass L4-type brown dwarf, which itself orbits a 0.4 solar mass M1V dwarf star. Since the planetary-mass object orbits a brown dwarf, which is neither a star nor a planet, whether this object should be labelled a planet or a moon is subject to some debate. The object has astronomers questioning taxonomy and classification in this low-mass regime. For now, the team that made this discovery labeled it an “exosatellite,” the first of its kind. While moons are a common occurrence in our own solar system, astronomers have yet to discover a true 'exomoon' in another star system. The CD-35 2722 exosatellite feels like a big step forward in the hunt for true exomoons!

CD-35 2722 B b, as it appears in SpaceEngine, with its brown dwarf host in the background.

The CD-35 2722 exosatellite is exciting for other reasons too; planetary-mass objects orbiting brown dwarfs, like this one, are rare. Systems where brown dwarfs host exoplanets invoke questions about formation history, with labels depending on whether the smaller object formed from a protoplanetary disk (making it a planet) or from the gravitational collapse of a giant molecular cloud (making it a very low-mass brown dwarf).

For further reading, the original article is at https://www.nature.com/articles/s41586-026-10751-w (paywall), or you can read this press release: https://www.space.com/astronomy/exoplanets/astronomers-may-have-discovered-the-1st-moon-outside-of-our-solar-system-or-is-it-something-weirder.

Star Browser Gas Giant Fix

Of final note is a fix related to gas giants in the Star Browser. Previously, searching for pressure ranges that included 1.0 atm would return every gas giant in range. While this presented as a technical bug, this was actually its correct behavior! In SpaceEngine, we use the conventional astrophysics definition for the 'surface' of a gas giant: the layer where atmospheric pressure equals 1.0 atm. So the surface pressure of gas giants is always 1.0 atm, by definition. But this isn't very helpful for the Star Browser's purposes, so we fixed the interaction. The Star Browser will now ignore gas giants when searching for worlds with a surface pressure range including 1.0 atm.

Changelog

• M-type brown dwarfs and L-type main sequence stars now have correct labels
• Planetary mass “star” objects with spectral type M and later will now be labeled as planemos
• Spacecraft materials now support gamma adjustment for Diff/Emis maps and green channel inversion for DirectX normal maps. The following parameters have been added for use in .sml files:
  • DiffGamma/EmisGamma: values greater than 0 behave as a simple power gamma adjustment, while values below 0 instead use a fixed piecewise sRGB to linear conversion
  • DirectXNormMap: a boolean that inverts the green channel if set to “true”
• Fixed a bug where searching for a planet in the Star Browser with a pressure range that included 1.0 atm returned every gas giant in the search radius
• Updated the CD-35 2722 system and added the newly discovered exosatellite CD-35 2722 B b
• Updated Jupiter’s size and shape with the latest Juno data
• Corrected Titan’s mass
• Updated distance to M 99
• Fixed distance, size, and orientation of Ring Nebula
• Added Ring Nebula’s central star as a catalog object
• Fixed distance, size, and orientation of California Nebula
• Reduced luminosity of Pleiades Nebula for increased realism
• Updated distance to Puppis A
• Added newly published properties for The Garnet Star
• Corrected orbital parameters of Mu Ara’s planets
• Removed liquid ocean from Wolf 1061 c
• Updated Gliese 777 system (removed extra planets, added missing d planet, updated properties for b and c planets)
• Updated the exoplanet catalogs with 27 new host stars, 30 new planets, and five new brown dwarf candidates
• Added 12 new binary asteroid systems, updated some binary system names
  • Added newly assigned name to 1999 JB80: Karolinadziadura

Catalog Additions

Binary Asteroids:

• Nysa
• Nash
• Korankei
• Tippett
• 2002 TC302
• 2014 GX53
• 1999 SY8
• 2013 HU156
• 2000 AO1
• 2003 SD106
• Harwood
• 1999 BG2

Brown Dwarf Candidates:

• HD 16760 b
• KMT-2023-BLG-0332L b
• TIC 52059926 b
• TIC 9344899 b
• TOI-6884 b

Exoplanets:

• Gliese 3378 b
• HD 5388 b
• TOI-3457 b
• TOI-707 b
• GJ 777 A d
• HD 125136 b
• HD 126105 b
• HD 127195 b
• HD 127195 c
• HD 190360 d
• HIP 10090 b
• HIP 10090 c
• HIP 39330 b
• HIP 8923 b
• HIP 98599 b
• KMT-2023-BLG-1592L b
• NGTS-38 b
• OGLE-2023-BLG-0766L b
• TIC 150070085 b
• TOI-1533 b
• TOI-1533 c
• TOI-2147 b
• TOI-3664 b
• TOI-4034 b
• TOI-6019 b
• TOI-6564 b
• TOI-791 b
• TOI-791 c
• BET Pic d
• CD-35 2722 B b