January 31, 2026
1 min read
Add Us On GoogleAdd SciAmLargest galaxy survey yet confirms that the Universe is not clumpy enough
The six-year results from the Dark Energy Survey highlight unresolved tensions in standard cosmological theory
The Dark Energy Survey observed around 150 million galaxies visible in Earth’s southern sky.
Erin Sheldon and the Dark Energy Survey Collaboration
Astronomers have released the most ambitious cosmic map assembled so far, confirming that matter in the Universe is less clumpy than standard cosmological theory would predict.
From 2013 to 2019, the Dark Energy Survey (DES) team repeatedly imaged a large section of Earth’s southern sky to collect the positions, colours and shapes of around 150 million galaxies. Using a telescope at the Cerro Tololo Inter-American Observatory in Chile, the team also detected and studied more than 1,500 supernova explosions of a type that can be used to track the expansion history of the Universe.
The team analysed four different aspects of the data: the brightness and other characteristics of the supernovae; the clustering of galaxies across space and time; the evolving size of remnants of pressure waves generated in the Universe’s infancy; and the distortion of images of background galaxies by large concentrations of intervening invisible ‘dark matter’.
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The combined results refine previous DES measurements to confirm that gravity has not clumped galaxies together as much as as much as observations of the early Universe would lead us to anticipate, were the standard theory of the Universe’s evolution correct — an ongoing puzzle for cosmologists.
This article is reproduced with permission and was first published on January 30, 2026.
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