Best of: The future of the universe

The universe, approximately 13.8 billion years old, continues to expand and accelerate, driven by the mysterious influence of dark energy and the gravitational scaffolding of dark matter. Mapping this evolution requires integrating 2D imaging with 3D spectroscopic data, which utilizes redshift measurements to determine the distance and age of celestial structures. While normal matter accounts for less than 5% of the universe, dark matter dictates the hierarchical formation of galaxies, where smaller structures merge over time to create complex systems like the Milky Way. Astrophysicist Risa Wechsler highlights the SAGA survey, which examines 100 Milky Way-like galaxies to provide a comparative context for our own galaxy’s formation history and satellite population. These large-scale surveys and simulations are essential for deciphering the fundamental composition of the cosmos and the mechanisms governing its ongoing structural development.