Momoshiki's Planet

In Boruto: Naruto the Movie, the majority of the movie takes place on an unknown planet where Momoshiki and Kinshiki hailed from. The planet itself located in an unknown star system in a certain corner of the universe.

Known Access
There are some ways to access the planet from the Earth: Both of the techniques use the power of Rinnegan.
 * With a portal created through an unspecified Space–Time Ninjutsu utilised by Momoshiki and Kinshiki.
 * With a portal created through an unspecified Space–Time Ninjutsu utilised by Sasuke.

Environment
The planet itself from outside seems to have a thick and cloudy atmosphere. The clouds are very thick and fully engulfed all of the planet's body and made it very hard to be penetrated by the system's host star's sunlight, caused the planet sky to be in perpetual gloom in black - red tone colour as in twilight.

Underneath the planet's atmosphere, the planet's surface is harsh, barren, and lifeless environment with a dull reddish landscape consisting of many craters, canyons, highlands, and mountains without any remarkable features. It also seems to be the same as the Earth in real life, having Earth-like gravity and an oxygen-enriched atmosphere, but lack of any trace of water.

Despite its extreme environmental conditions, the planet is still capable of sustaining specific lifeforms. It hosted a Shinju which appears much older than Earth's, which was later destroyed due to Kinshiki's actions. Some Ōtsutsuki appear to having arrived there at some unspecified time, and able to have descendants for generations, and eventually only Momoshiki and Kinshiki survived.

Trivia

 * Being able to host a Shinju in there, its unknown if this planet in the past also hosted a certain sentient being and also shared the same dark past like the Earth, where countless battles also plaguing here and the blood of deceased spilled there, leading to the planet's Shinju creation.