Although astrophysicists still have a lot more to learn about dark matter and its origin, the structure still appears under our nose pretty often. Of course, we must interpret ‘under our nose’ in this case in an astronomical way, meaning hundreds of thousands of light-years away. For us humans, it would take forever to travel such distances, but they mean nothing for the Universe.
The main attraction point this time is located at 163,000 light-years away from our own galaxy: Tucana II, a dwarf galaxy that revolves around Milky Way.
Tucana II is surrounded by a dark matter halo
Anirudh Chiti, an astronomer from the Massachusetts Institute of Technology, said:
We know [dark matter] is there because in order for galaxies to remain bound, there must be more matter than what we see visibly, from starlight,
He further added:
That led to the hypothesis of dark matter existing as an ingredient that holds galaxies together; without it, galaxies that we know, or at least of the stuff at their outskirts, would just fly apart.
Perhaps the more incredible aspect is that Tucana II’s gravitational bounds (the dark matter halo) are at least three times more massive than previously thought.
Tucana II is one of the oldest galaxies known, and it came as a surprise for astronomers that even such groups of stars can feature halos made of dark matter.
Although scientists have no idea what exactly dark matter is, they know that it’s real due to the excess of mass from the galaxies. Hopefully, such secrets of the Universe will be uncovered in the near future.