u/Maxijohndoe

Eyrgiafa system has four gas giants and a couple of small planets, one being a trojan escaped moon of Rehman.

Note that Mongoose has made a really weird system with a number of massive moons. And by massive I mean from Mars size up to a Super Earth.

To have enough gravity to hold such massive moons means gas giants far larger than Juptier. This gives those gas giants a large Jump Shadow.

To attempt to mitigate for the Canaveral part of the campaign I have that station orbiting outside of the moons, but given the low M-Drive ratings of trucks that still means a close to 24 hour trip from the jump in point to the station.

Edited to add: The space stations are screen shots from No Man's Sky of player space stations.

Once again I have created a seperate Eyrgiafa folder in my Drop Box.

Link to Dropbox post Drop Box for all my Planet Information and System Maps

As people always ask I created these using a software program called Universe Sandbox.

As always feedback and corrections are welcome.

I have made a major change to how I will be posting in that I will be posting individual systems instead of a number of different systems.

Note that the above isn't every planet and moon in the folder but I have hit the image limit. You can find all the files in my Drop Box.

This is because I have created a planet card for every rocky planet and moon, and all listed Starports and Space Stations.

Edited to add: I should note that I have created a number of moons because the system as shown on the map in Cluster Truck has five gas giants and two large size 9 planets but only one listed moon.

I will also have seperate system folders in my drop box as well.

Link to Dropbox post Drop Box for all my Planet Information and System Maps

Due to its low tech nature a lot of Cluster Trucker occurs inside solar systems rather than a lot of jumps between different systems.

In fact for anyone who wants to run a TL 8 game the Estuary Cluster and the Cluster Truck rules does the trick.

However the actual Cluster Truck campaign may be a bit to railroady for people who prefer a sandbox.

Given how much work a single system takes it is going to take a bit of time to finish the remaining eight systems.

As people always ask I created these using a software program called Universe Sandbox.

As always feedback and corrections are welcome.

For anyone running or planning to run Cluster Truck I'd like to check if the following works for you or if you can see how things could be improved or changed.

As in-system travel plays a major role I am creating planet cards for every planet and moons that has stats in the book.

The solar system map format remains unchanged as it is primarily used for jumping between systems.

The major difference is that I am creating Starport cards. These are stations built in the game No Man's Sky put through some filters in GIMP.

There is a lot of free space for information on the Starport card so what if anything could be added?

This is the fourth and final group of seven planet and system cards for the Glisten Subsector.

Also I am adding all new and updated planets and systems to my Dropbox as they are finished.

Link to Dropbox post Drop Box for all my Planet Information and System Maps

As people always ask I created these using a software program called Universe Sandbox.

As always feedback and corrections are welcome.

THIS represents a milestone for me personally.

1 Sector

16 Subsectors

439 Systems

Innumerable solar systems and planets

2,508 hours in Universe Sandbox (to be fair some of this was letting the simulation run to get the results I wanted. I am not completely insane).

This project started back in October 2024 when I decided to use a program called Universe Sandbox I had bought off a STEAM sale to make homeworld planets for the Travellers in my new campaigns.

Nearly two years later I have detailed a few systems in Foreven, a small strip of Gvurrdon, half of the Trojan Reach, and today the whole of the Spinward Marches.

Why?

For my own education and entertainment, and because I know from decades of DMing, GMing and Refereeing TTRPGs just how much work goes into running a successful game of Traveller.

I'm just happy to help.

Going forward I am reworking my Drop Box post to make things clearer for people trying to use it.

I also plan to complete Gazulin Subsector in the Trojan Reach. That will provide nine complete subsectors along with a few other systems that are part of Pirates of Drinax.

Edited to add: I should also thank the community. It has been your feedback, criticism and support that helped to turn a half-baked idea into something useful. Cheers!

After that.......

This is the third group of eight planet and system cards for the Glisten Subsector.

I have detailed Lydia and Mithras in previous posts.

Note that I have lightened the planet image of Mithras to make the details more visible. A realistically dark red version exists in the Mithras Prison Planet post.

New Rome is also a S-type binary with a Primary and Secondary System.

It also has a second world Bellion with a population in the millions. Bellion was once the main world and the capital of a pocket empire, until the Imperium imposed its will, and eventually the more industrial planet of New Rome became the main world.

Romar is a major producer of Dustspice and as a result is of great interest to the Aslan of the Trojan Reach.

Also I am adding all new and updated planets and systems to my Dropbox as they are finished.

Link to Dropbox post Drop Box for all my Planet Information and System Maps

I plan to eventually finish the whole Spinward Marches. I am down to Glisten as the final Subsector but it will still take a bit of time to finish.

As people always ask I created these using a software program called Universe Sandbox.

As always feedback and corrections are welcome.

Interesting how the Traveller lore manages to align with the reality of a weird Solar System.

Mithras Primary was a Red Giant Star somewhere around 8.8 Solar Masses. Thirty million years ago it was in the final stage of its life, on the verge of going Supernova and collapsing into a Neutron star, when a chance stellar encounter saw a Red Dwarf Star performing a close fly by.

The gravitational effect tore open Mithras Primaries Chronosphere, briefly exposing its Photosphere, leading to a massive erruption of gas that reduced the star's mass and extended its life.

The gravitional drag from this event slowed the passing Red Dwarf star sufficiently for it to enter a decaying S-type binary orbit as Mithras Secondary. It slowly drifts in closer to Mithras Primary over time, and will eventually settle into a close orbit with the future White Dwarf Mithras Primary.

But that is millions of years into the future.

The planet Mithras is a core remnant of a small Neptune like Gas Giant whose atmosphere was erroded away by Mithras Primaries flares and solar wind. While roughly Earth sized, the planet is far denser with a strong magnetic field, allowing it to retain some water and atmosphere.

When Mithras Secondary tore open Mithras Primary a huge amount of hydrogen, Helium and Oxygen was expelled from the star. Some of these gases where captured by Mithras, restoring the oceans and supercharging the atmosphere with oxygen. The current concentration is 35% and lethally corrosive. This oxygen combined with gases escaping from Mithras's core has supersaturated the oceans, with disolved gas held by the high atmospheric pressure at sea level. If this pressure is reduced the water explodes like a shaken soda can.

All of these weird circumstances made Mithras attractive to the Third Imperium as a prison planet. Mithras is an oubliette, a place the Imperium sends its political exiles and the criminals it wants to forget ever existed.

And it is the Solar System itself that makes Mithras an inescapable prison.

Mithras Secondary and all the planets fall well within Mithras Primaries massive 120.034 AU Jump Shadow. A starship entering the system faces a journey of a month to two weeks in system to reach Mithras directly.

Imperial starships bring in prisoners instead first travel to an orbital base located at the Gas Giant Attis that orbits Mithras Secondary, a journey that takes twenty two days days to ten days depending on the M-drive.

Here prisoners and any cargo are transferred to a in-system ship for a ten day trip to a base located on Mithras's moon Petra. Finally the prisoners and any cargo are loaded onto specially protected transports for the trip down to the planet itself.

The prison is a series of underground facilities built into the tops of the highest mountains. Here the atmospheric pressure is more survivable. No Imperial personnel ever venture beyond the docks or enter the prison itself.

Instead it is the prisoners who are tasked with running and maintain their own prison, growing their food in hydroponic bays and performing all necessary maintenance.

As a result escape is near impossible. Even in a Hostile Environment Suit survival time on the planet's surface is measured in hours. Hijacking a transport would only get the prisoners as far as the base on Petra where they would face armed resistance. If the prisoners somehow managed to hijack an in-system transport that would only get them as far as Mithras Secondary, with the authorities having many days to prepare for their arrival.

Any starship coming in to attempt a rescue faces weeks in transit time in and out from the edge of the Jump Shadow. There is no uncontested refueling at either of the gas giants, and any crew that attempts it faces great risk refuelling on Mithras itself.

Just my head canon based on the Traveller lore for this system.

Oh and I decided to use the actual light provided by Mithras Primary to show just how dark and creepy Mithras actually is.

One of the issues with Science Fiction Space TTRPGs is a lack of imagery.

What does a orbital space station look like?

How does the surface of an alien planet differ from say Earth or Mars?

I made a series of images using screenshots from the video game No Man's Sky that I then processed a bit in GIMP.

The idea was to provide framing images so the players had a visual understanding of what I was describing in text.

I created a ship in NMS that represents a generic small FTL capable starship I call the Argo.

The city is a community project built by players within NMS.

Like my planet images I have saved these images in a free to access Drop Box folder that you can access via your browser: you DO NOT NEED A DROP BOX account to copy them.

NMS vibe images

As these were made using No Man's Sky assets these images are for personal use only. All rights belong to Hello Games.

I will add more images over time.

I cleared this with the mods.

I should add that the above images are just a sample and there are currently 48 images in the folder.

This is the second group of eight planet and system cards for the Glisten Subsector.

Crout is a S-type binary systems with two seperate solar systems Primary and Secondary.

The Crout system has a M7 III Giant star. This is where parts of Traveller shows it age. This Star is too large for it listed mass, to the point where the star loses its outer layers to space. While this does match the final stage of a dying Red Giant Star Crout M7 III's mass means that it would supernova, effectively destroying the system as well as impacting nearby star systems.

So I adjusted the stars parameter to fit the system info as per the Wiki.

The planet Egypt is interesting because it is on the verge of becoming what we would now term a mini Neptune. You have a rocky super Earth with enough gravity to hold onto a very dense atmosphere. It is also cold enough to retain a lot of free Hydrogen gas.

This makes Egypt's insidious atmosphere unique among all the planets I have detailed to date. Hydrogen is a difficult gas to store because its atoms are so small diffusion occurs as the Hydrogen passes through the container material.

Egypt's atmosphere poses the reverse problem - keeping Hydrogen out. With the atmosphere being around -50 degrees and 8 x atmospheric pressure Hydrogen will seep into Vacc Suits and habitats before warming up and becoming a combustion hazard.

Also I am adding all new and updated planets and systems to my Dropbox as they are finished.

Link to Dropbox post Drop Box for all my Planet Information and System Maps

I plan to eventually finish the whole Spinward Marches. I am down to Glisten as the final Subsector but it will still take a bit of time to finish.

As people always ask I created these using a software program called Universe Sandbox.

As always feedback and corrections are welcome.

This is the first group of six planet and system cards for the Glisten Subsector.

Aki, Bicornn and Caledonia are all S-type binary systems with two seperate solar systems Primary and Secondary.

I have also included three systems from Firgr Subsector in the Gvurrdon Sector. This is just over the Spinward Marches border into the Vargr Extents.

This fills in all the systems that sit just across the border from the Spinward Marches Regina and Aramis Subsectors.

It seems that the border systems have a mixture of old Imperial names with the Vargr renaming systems and worlds as each new groups move in.

When the mood takes me, and I have suitable alphabet soup names, I will slowly add more Vargr systems.

Also I am adding all new and updated planets and systems to my Dropbox as they are finished.

Link to Dropbox post Drop Box for all my Planet Information and System Maps

I plan to eventually finish the whole Spinward Marches. I am down to Glisten as the final Subsector but it will still take a bit of time to finish.

As people always ask I created these using a software program called Universe Sandbox.

As always feedback and corrections are welcome.

This is the fourth and final group of two planet and system cards for the Mora Subsector.

As a bonus I have include five systems from Uthe and Firgr subsectors in the Gvurrdon Sector. This is just over the Spinward Marches border into the Vargr Extents.

It seems that the border systems are a mixture of old Imperial names with the Vargr renaming systems and worlds as each new groups move in.

So I accepted the Vargr naming tradition of rolling your face across the keyboard (or I took system names from No Man's Sky) and just ran with it.

When the mood takes me I will slowly add more Vargr systems.

Also I am adding all new and updated planets and systems to my Dropbox as they are finished.

Link to Dropbox post Drop Box for all my Planet Information and System Maps

I plan to eventually finish the whole Spinward Marches but it will take quite some time.

As people always ask I created these using a software program called Universe Sandbox.

As always feedback and corrections are welcome.

This is the third group of eight planet and system cards for the Mora Subsector.

Moran, Nadrin and Nexine are S-type Binary systems with two seperate solar systems: Primary and Secondary.

Also I am adding all new and updated planets and systems to my Dropbox as they are finished.

Link to Dropbox post Drop Box for all my Planet Information and System Maps

I plan to eventually finish the whole Spinward Marches but it will take quite some time.

As people always ask I created these using a software program called Universe Sandbox.

As always feedback and corrections are welcome.

This is the first group of seven planet and system cards for the Vilis Subsector.

728-907, Asgard, Calit and Caloran are all S-type Binary systems so I have created two system maps Primary and Secondary.

Also I am adding all new and updated planets and systems to my Dropbox as they are finished.

Link to Dropbox post Drop Box for all my Planet Information and System Maps

I plan to eventually finish the whole Spinward Marches but it will take quite some time.

As people always ask I created these using a software program called Universe Sandbox.

As always feedback and corrections are welcome.

I have a confession to make ... I have been cheating on you all.

I have been flirting with the Stars Without Numbers Reddit,

But like all guilty cheaters I have come crawling back to you all with a gift. For the homebrewers I have combined all of my blank planet images into one location.

>This is the link to my Drop Box where I have a collection of blank planet images.

>Blank Planet Images

>Currently there are 622 individual images that covers a range of planets, gas giants and asteroids.

>You can access these files directly via your browser. You do not need a Drop Box account to download the files.

>I give permission for anyone to use these in their games, and to modify them if they so desire.

>If anyone wants to use these in a commercial product credit Maxijohndoe on Reddit.

>As people always ask these images were created using a software program called Universe Sandbox.

As I complete a Subsector I'll copy all the blank planet images to here as well.

Note that it is still easier to search for a Traveller planet in the Subsector folder as there are duplicate named systems so some will be overwritten in the blank planet folder.

I am slowly approaching the completion of the entire Spinward Marches, and when I do I'll reorganise my Drop Box post it make things a bit clearer.

A while ago someone was asking about a diagram or map of moons around a Gas Giant.

I was working on the Arkadia System when I realised this was a good example.

This is the small Gas Giant Psari, a mere 14.4 Earth masses.

Even so it has a whole host of moons.

Normally I only record the big moons but this time I have detailed them all.

You have an outer layer of irregular moons in highly eccentric orbits.

Closer in you have a second layer of irregular moons.

Finally you have a tight group of regular and shepard moons with a belt system.

A Gas Giant's moons are harder to show in 3D than a whole solar system as the orbits are far more chaotic.

If the person who asked is still around I hope this helped.

This is the link to my Drop Box where I have a collection of blank planet images.

Blank Planet Images

Currently there are 622 individual images that covers a range of planets, gas giants and asteroids.

You can access these files directly via your browser. You do not need a Drop Box account to download the files.

I give permission for anyone to use these in their games, and to modify them if they so desire.

If anyone wants to use these in a commercial product credit Maxijohndoe on Reddit.

As people always ask these images were created using a software program called Universe Sandbox.