Clusters of galaxies are the largest stable systems in the universe
They are like laboratories for studying the relationship between the distributions of dark and visible matter
The visible component of a cluster, billions of stars in each of the thousands of galaxies, represent only 15-20% of the total mass
The rest is the mysterious, invisible, dark matter
The image spans just one-tenth of the diameter of the full moon
[...]
The question is [2x]
Can we make it [2x]
Back to Earth?
Just below the constellation of Orion, [...]
The image spans just one-tenth of the diameter of-
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