Quintessence (Dark Energy) & Dark Matter
I like your analogy of "dark matter in space" to the "dark matter within" (the shadow side of self).
First I do want to point out the difference between what cosmologist call "dark matter" verses "dark energy."
Quintessence, coined by Aristotle to describe the eather, is the term used by modern physicists to describe the quantum field of "dark energy" permeating space. This was in an effort to fit into cosmological theory Hubble space telescope's observation that the universe is expanding, and that its rate of expansion is increasing, despite the coagulation of energy into denser matter--the galaxies and stars we do see. Classically, Quintessence refers to the fifth unseen element. Note also that "5" is the number of human, making possible the ascension from the lower quaternary world or platform up which we participate made up of Earth Air Fire and Water. A fundamental concept in astrology is that our passage around the Zodiak (or karmic wheel of life), our participation in the four elements, is our means of soul growth and ascension / graduation from the wheel of incarnate life. Note too that within the circle forms the square (the Holy Cross) or timepiece governing this process--our evolutionary cycle of the soul. See the Holy Cross web page.
From one of my LP writings discussing the Super Galactic Center and "Dark Energy" for persepctive:
Our Galaxy, the Milky Way, is a whirling disc composed of hundreds of billions of stars, of which our sun is one, spinning around a dense and massive bulge of stars and a black hole called the Galactic Nucleus or Galactic Centre. Our galaxy is one of about 30 galaxies comprising a cluster of galaxies called our "Local Group." The galaxies in our Local Group gently revolve around each other much like organisms floating in a protective embryonic fluid.
Our Local Group is merely one galactic cluster of many that comprise yet a large group called our "Local Super Cluster." All of these embryonic clusters, harboring many evolving galaxies and forms of life, are like protective cocoons floating within the care of the Super Cluster.
The Virgo Cluster, one of the larger members of the Super Cluster, is comprised of about 200 known galaxies and it lies at the center of our Local Super Cluster. "Super Galactic Centre" (SGC) is a term that refers to a point in the Virgo Cluster that marks the centre of our entire Super Cluster. The super-giant galaxy M87 composed of ancient stars in the Virgo Cluster is believed to mark or lie very close to the Super Galactic Centre--a black hole believed to be about five billion times as massive as our sun. Our Galaxy, nested in our Local Group, lies about 50 million light years distant from the Super Galactic Centre.
If this is not expansive enough for one's mere mortal mind, this vast field of consciousness, which suspends an unlimited number of Galactic Clusters, all unique with their own galaxies and their diverse star systems, is also filled with "Dark Energy," a permeating field of energy that we do not see. Space, at one time thought of as empty, is now recognized to be comprised of substance--perhaps a step toward recognition of the creative intelligence permeating space. Honoring this underlying or transcendent nature of reality, astrophysicists have come to call Dark Energy, "Quintessence," a term once used by Aristotle to describe the eather. We call this, all of the astrophysical diversity we have come to detect, this field of magnificent stellar creation, our "Known Universe"; and what we see in it, is but through our very limited, electromagnetic-spectrum, lightspeed-dependent modality of perception. Yet still, it appears this Known Universe is too but a bubble of perception amongst an infinity. So let us keep perspective of our lives on Earth and rise to the embracing awareness of the precious gift life is.
Just as all stars and deep space objects we observe and discuss astrologically, recognizing them to be a multitude of facets of our greater consciousness, of Divine Intelligence, so too is Quintessence (dark energy) a part of our consciousness--the unseen unified field in which the many visible specs or aspects of self float--as well as the "dark matter." Considering Quintessence is far vaster than that which we do see, this is a statement that there is far more of what we do not see about ourselves than that which we are aware of--affirming we are fathomless beings. To transcend (surrender) our descriptions (judgments) of self and of the world (that which we do see) through meditation is one way to delve into and ride upon this ever-expanding quintessential force--to discover the unimaginable, the unlimited vastness and potential within; even to embrace our "dark matter."
Regarding "dark matter": The term "matter," of course, refers to materialization, and subsequently is that which we place importance upon, that which matters. Paradoxically, what does not "matter" may be of more importance. In this light affirming that relinquishing self-importance (placing importance on that which matters), is an important step in getting to that which transcends matter and really matters--Quintessence, the underlying Force that can really make change if we learn to use it and navigate upon its currents.
But back to "dark matter." Does "dark matter" matter. In the context of your original association of dark matter in space to the dark matter within, it must have equal validity, equal to "light matter" (that which we do see / are OK with)--so we need to embrace both. An "active" meditation technique is to visualize bringing light into the body, starting from the head down. In the process, slowly allowing it to fill every area of the body, every nook and cranny, every cell. When finding a place (of dark matter) where the light does not seem to want to go, focus upon that place and allow the light to shine on the darkness, embracing it, permeating it. In doing so we start to see and feel things within self that we have been holding in darkness / denial--suppressed areas of our stored experience that we did not want to look at (and feel) for one reason (judgment) or another--this being an important step (from a quintessential perspective) in our growth / illumination.
Perhaps our astronomical recognition of dark matter is a statement of humanity being faced with the "need to look" at that which we do not see (or do not want to look at) to make the transition from bio-logical beings that merely describe that which we do not know, to bio-illumined beings that super-conduct consciousness and epistemologically realize the unlimited beings we truly are, and graduate into unified field awareness / cosmic consciousness.