Tretris Oakutarui has 7 moons orbiting above its surface, 2 of which are habitable. Tretris being with its massive gravitational pull being similar to that of a gas giant, has captured 4 of the moons, 3 of which were natural. The most famous of these moons is Meridum.

Meridum: Named after the Intelonian Scientist that proposed the Terraforming Plan, Xyryn Meridum

A captured moon and the habitable moon of the planet. Dating back since the Intelonians, Meridum is one of the 4 captured moons that orbit above. Originally a dead moon, the Intelonians started a secret project that not even the Dragon Guard had any word, since they started to fear the Dragon Guard was starting to gain sentient so they kept the project secret, but keeping the Dragon Guard in distance, they feared that other smaller empires may infiltrate the city and steal the project. This secret project became later was is known as Terraforming. They transformed the dead moon into a tropical moon, this great achievement however didn't get to celebrate its fullest as by then the Intelonian Empire collapsed. Meridum became popular again when the System Wars happened, When the Oltanians forcibly captured Tretris Oakutarui and razed its cities, Meridum became the temporarily Capital of the Republic since Tretris was occupied by the Oltanians. They transformed the tropical moon into an ecumenopolis, however after the System Wars the Republic realized the damage they done to the moon, the ecumenopolis that made the moon became a disaster, so the Republic slowly removed the Cityscape and replaced it with its original landscape or what many thought its original landscape the tropical jungle. The only remnants of this cityscape is found in the cities of Meridum, the most famous is Meridum City. However Meridum will once again become famous again, during the First Intergalactic War. Meridum became the target of an morale effect, the Oltanians had the opportunity to raze Tretris to the ground, however they targeted the moon of Meridum. Oltanians appeared above the moon's surface and began to bombard its surface, its citizens caught off guard failed to evacuate the moon in time. The bombardment not only razed the surface, its atmosphere turned acidic and evaporated, any life that survived the bombardment eventually died without an atmosphere to live under.
Eventually after the war, Meridum became the center of Terraforming Tech, it became the stepping grounds of the Terraforming Era. They believed if they can rebuild Meridum than they can rebuild entire planets that were devastated in the First Intergalactic War. Meridum's reconstruction became a success! After 30 years, the Moon was rebuilt, however to its former tropical status was impossible, it was restored to a temperate climate. Its cities were rebuilt already, but due to the destruction of the landscape, many cities weren't rebuilt and became ruins or slowly faded into the rebuilt landscape. Most of the cities of Meridum are later centered in Meridum Maas, a massive caldera located in the Northern Hemisphere of the moon. Here farmlands scretch for miles, wtih a mild touch of cities.

Trisun: Named after the Three Suns

The other Habitable moon and one of the 4 captured moons, Trisun is only mentioned due to holding the Velevettrone Maximum Security Prison, the most heavily guarded prison in the galaxy. It was built after the First Intergalactic War to keep the POW's in a place to watch over, Its surface is very rocky and semi arid.

Delomos: Named after the ancient Intelonian City that was once occupied the Rilgar System
-Delomos is a rocky planet its orbit brings it a near vertical orbit. Its part of the many dummy moons to the Defensive Network of the Capital City.

Selski: Named after the tallest peak in the solar system, Mount Selski.
This moon is famous cause it holds the tallest mountain in the entire Three Suns System, Mount Selski, here its home to a tourist attraction, where Gravity Ski-ing is very famous. Skiing down Selski's slopes is a fun challenge to experience the actual Gravity Skiing.

Intelus: Named after the Intelonians, believed to be the dwelling of the Intelus the Galactic Dragon. Due to its dragon shaped canyon that cuts its surface.
As mentioned, this small moon is famous for its Dragon Shaped Canyon that cuts its surface, its believed by the Intelonians that Intelus the Galactic Dragon resides in the moon.

Crakertus: Named after the massive crater that makes it surface.
Many years before it was cataloged, a large meteor struck the small moon almost breaking it, this created a large crater, the impact began raining debris onto Tretris Oakutarui. This event according to the Intelonians was known as the "Day when the Sky Fell". Despite what many scientist, Crakertus actually has a thin atmosphere, but it only happens when it gets too close that the atmosphere of Tretris actually engulfs the moon created a similar thread.

Un-named Moon: Its name is still unknown since it was recently discovered, the science wing is still deciding on what name it should be called.
As implied above, this moon was recently discovered the small moon is said to believed captured, this un-named moon is still being decided a name, it also believed that this moon may also be habitable due to a very faint tint showing an atmosphere.