Since launching in 2022, the James Webb Space Telescope (JWST) has transformed our understanding of the universe, particularly its early stages. Yet, one big question remains: What exactly is dark matter? New research hints that JWST might soon shed light on this cosmic puzzle.
Dark matter makes up about 85% of the universe’s matter, but we can’t see it. It doesn’t interact with light, which is why it stays hidden from our direct observations. Scientists know that dark matter isn’t made of protons, neutrons, or electrons—the building blocks of everything we see around us. Despite various theories about what dark matter particles could be, we still haven’t found concrete evidence.
To detect dark matter, scientists look at its gravitational effects on regular matter, such as stars and galaxies. A recent study published in Nature Astronomy suggests that dark matter might be behind unusual, elongated galaxies found by the JWST. Investigating these shapes could lead to new insights about the nature of dark matter.
Rogier Windhorst, an astronomer at Arizona State University, explains, “In an expanding universe, galaxies grow over time, starting from small clumps of dark matter.” The JWST reveals that early galaxies might be connected by filaments, which behave differently from the traditional view of dark matter. This difference hints that dark matter could consist of ultralight particles that exhibit quantum behavior.
When scientists use simulations to replicate how galaxies formed, they typically find spherical shapes matching those seen today. However, JWST observations show oddly shaped, elongated galaxies that challenge these models.
Windhorst and his team explored different dark matter types beyond the widely accepted “cold dark matter,” which moves slowly. They considered “fuzzy dark matter” or ultralight axion particles, which might explain the unique shapes of early galaxies. If these ultralight particles are indeed the makeup of dark matter, their behavior would lead to smoother, more connected structures in the universe.
Moreover, “warm dark matter,” made up of faster-moving particles like sterile neutrinos, might also lead to these elongated forms. Both scenarios suggest that how dark matter behaves fundamentally influences galaxy formation.
Research on dark matter and its role in shaping the universe is ongoing, with JWST continuing to explore these intriguing galaxies. As scientists refine their simulations and align them with new observations, we might finally arrive at a clearer understanding of dark matter.
For further reading, check out the study in Nature Astronomy here. With space exploration continually advancing, our quest to understand dark matter promises to uncover even more cosmic secrets.
