Yes it is fairly possible. I'll add a little more information as you can't ignore or skip over the hows and whys when discussing anything.
As a cullular manipulator the breathern moons/Necromorphs would have capabilitys we see in nature, like deep sleep hibernation stasis, cellular regeneration and surviving without need for food.
There is bacteria that was discovered outside of earths atmosphere on a satelite. Bacteria that can survive in the void/vaccum of space, as well as viruses(more specifically pyrons and a little dabbling with crispr to create a super virus) that can potentially forgoe alot of what we know about biology.
Plus the way these moons are created and develop are fascinating. Development Points that shouldn't be ignored when discussing things beyond ourselves in the limited perception we have of our place in the universe.
People are missing many of the realistic aspects of what necromorphs and the markers are. The breathern moons are just a product of the assimilation process caused by their energy source.
The real cause of how they begin is there are two distinct sets of Markers. A black one and many red ones produced by intelligent life that just so happened to be unfortunate enough to come across the black markers, or lead to reproduce them. The black one acts as a radio beacon or a relay thats connected to the other breathern moons.
For awnsers to some of your questions about how they move and their energy source, as well as how they are created. See the background information and where the developers have pulled their inspirations. They tended to get too imaginitive with the reality of science though.
black markers are sent out by these giant masses of infected living flesh and dead flesh. Creates a signal that draws intelligent life to it or creates lesser intelligent life to evolve to a higher conciousness. We are after all discussing entitys that are practically gods compared to us humans.
Every breathern moon is another previously assimilated intelligent species thats been cultivated and usually evolutionarily forced to a higher consciousness through the frequencys abilities to alter brain function. Consider the game to be in itself a darker horrifying theory on the theory of life in the universe. Its much more of a self exploratory look at cosmic horror.
Its unknown as to how it creates these black markers but my best educated guess is probably from iron and some other things to create an aloy from the blood in our own biological systems. Giving it structural support that can reinforce into steel with the already present carbon and resources pulled in through its assimilation process. Adding on to the hollow layer theory which could also allow it to propel itself through space like a jelly fish or octopus.
But the black marker itself is both a limitless power source that creates its own energy through some highly advanced use of frequencys that also effect psycho/nuerological brain function.
The red markers are the source of a reanimating bacterial(realistically it'd be a super multicelled virus) disease through airborne contact or direct infection from the freshly reanimated bodies that aren't fully dead. As the brains consciousness may die but not at the cellular level giving the bacterial or more realistically a super multicellular virus that can hijack the hosts reproductive cellular mechanisms.
As well as emitting a frequency that can not be heard or measured let alone have any safe gaurds created for many reasons. I.e its ability to alter the mind. Im guessing this frequency could also use the solar winds or energy and sail upon those or know its direction. Or as mentioned in the above posts using gravitational pull and slingshoting.
As it is a more natural free hive mind in a way that doesn't need to control everything it has used as its weaponized drones.
This frequency is where its limitless power also comes from. As the shape of the marker apears to create the ideal structure to let the frequencys bounce and absorb through a complex generative absorbing crystal structured like an acoustic/rely that allows them to have a limitless source of energy. One we and any advanced enough life form would see as absolutely the greatest find for our own technological advancement. Which would somewhat explain where it could generate enough power to create the assimilation process once intelligent life produces more markers.
The frequency then allows for a change in intelligent organisms behaviour, starting as a drive to recreate the marker. But it hides its true intentions behind this drive like a religous ferver. Tricking intelligent life capable of reproducing the red markers into creating many so the chances of total assimilation are secured. Isaac clark the main protagonist as strong willed and capable as he was. Also suffered the effects upon being in a rather far proximity to one marker.
As size of the markers don't. Really matter. But the red marker is different to the original black marker. Red ones emit a psycho/nuerological frequency that instead of drawing those towards wanting to understand and recreate it. The red ones turn intelligent life insane or suicidal, or pursue its cause to make itself whole.
Turning intelligent life insane, violent or suicidal. Is a very real and scary fear that we have some counter measures against. But because of of the widespread chaos feom a behavioral collapse allowing for the bacteria to spread and infect dead cells until it gets to a critical mass.
Where it then pulls in all the dead and living matter with a gravitational pull that also pulls in other matter. Buildings and loose earth.
Even a fragment of the red markers emits the signals frequency.
The horrifying part that exists in our reality. Is how these Markers emit frequencys that can change human behaviour. As well as the use of this frequency as an energy source.
Now lets say the bacteria that lives in the vaccum of space, works the same as the infectious necromorph bacteria. but this bacteria repurposes and reanimates cells like a super multi celled virus that can also infect living tissue in the freshly dead, or the willing or unwilling living hosts. Which can create stronger replicating living tissue which created the regenerating hunter in game. Repurposing tissue to have the capability to survive in space.
A reason that something that large could then exist in the vaccum of space would be its hijacking ability to overide natural safety switchs and the ability to repurpose bio organic material. It could create a membrane around itself that could fight cold and radiation or adapt to whatever needed, which could then also repurpose some of itself to become the tendrils to propell itself through space. Or act as a means to sense and help rely signals from different directions to the other breathern moons.
Theres alot of complexity put into the thought and background of the Breathern moons.
The game is rather scary close to reality and many wouldn't want to know the truth behind certain aspects of cosmic horror. The things beyond our fear and understanding of the universe much like if one could peek into the 4th dimension.
Low frequency that could potentially be manipulated to create limitless energy.
The impact frequency can have on humans.
The bacteria that can live in the void.
How a super virus/bacteria that is multicelled could have the potential ability to hijack our cellular reproduction. And just a bit extra on how dead cells can be manipulated.
The frequency that could potentially be emitted that could effect human behaviour and the brain.
Mind you this is nothing more then speculation and theory on the existance of life that is greater then ourselves on the cosmic level. I am also having trouble finding the sources where i've drawn more darker information and my own conclusion so I will not be adding that extra stuff.