A new high-resolution map of distant galaxies created from NASA’s James Webb Space Telescope images could help scientists better understand dark matter, an invisible substance that makes up just over a quarter of the universe.
The map, published Monday in the journal Nature Astronomy, is intended to clarify a long-standing mystery in cosmology by showing how dark matter’s gravity affects what telescopes can see. Dark matter does not absorb or give off light, so researchers cannot observe it directly. Instead, they study how gravity warps and bends the light from faraway galaxies, allowing them to infer where dark matter lies.
In the account of the new work, ordinary matter—stars, planets and people—makes up 5% of the universe, while dark energy is described as making up the rest. Together, those shares frame dark matter as a dominant component that is difficult to detect because it does not emit its own light.
The latest map is described as the most detailed yet over a large patch of sky, built from observations that capture hundreds of thousands of galaxies over the past 10 billion years. The report also says the map has twice the resolution of previous attempts using the Hubble Space Telescope.
The study used the James Webb telescope to produce a high-resolution view across that period, and the resulting product includes information on new galaxy clusters and on strands of dark matter that connect them. In that description, the structures build up the universe’s “skeleton,” with dark matter clumping over billions of years forming a cosmic web.
Study author Diana Scognamiglio of NASA’s Jet Propulsion Laboratory said in the report, “Now, we can see everything more clearly.”
Astrophysicist Rutuparna Das, of the Harvard-Smithsonian Center for Astrophysics, was not involved with the new study. Das said, “As humans, we’re naturally curious to know more about where we come from and that story can’t be told without dark matter,” and added, “Our home is the universe and we want to understand what the nature of it is.”
The story also characterizes dark matter as something that passes through the body all the time without obvious interaction, while still shaping the universe on a much larger scale.