From CNN, Dec. 18, 2020: Fermilab scientist Don Lincoln summarizes the results of a group of researchers who, through simulation, reconstruct the family tree of the Milky Way, including the merging of the previously unknown dwarf galaxy Kraken.

Scientists on the Dark Energy Survey have used observations of the smallest known galaxies to better understand dark matter, the mysterious substance that makes up 85% of the matter in the universe. The smallest galaxies can contain hundreds to thousands of times more dark matter than normal visible matter, making them ideal laboratories for studying this mysterious substance. By performing a rigorous census of small galaxies surrounding our Milky Way, scientists on the Dark Energy Survey have been able to constrain the fundamental particle physics that governs dark matter.

From New Scientist, July 15, 2020: Two sets of measurements to estimate the rate of expansion of the universe — described by the Hubble constant — conflict with one another, which may be a sign that our basic understanding of the cosmos is wrong. Two new attempts by astronomers to solve this problem have complicated things further. Fermilab scientist Antonella Palmese and her colleagues have used measurements of gravitational waves to calculate an independent value of the Hubble constant.

From Live Science, April 29, 2020: One of the deepest mysteries in physics could be explained by a long-since vanished form of dark matter. Fermilab scientist Dan Hooper is one of the authors of the new result. If an ancient form of dark matter decayed out of existence, that loss would have decreased the mass of the universe, which would have led to less gravity holding the universe together, which would have affected the speed at which the universe expands — helping explain the disagreement between measurements of the universe’s expansion.

From Five Books, March 30, 2020: Fermilab scientist Dan Hooper gives his recommendations for books on the Big Bang and talks about whether our entire understanding of the universe is about to be turned upside down.