Astronomers create clearest map yet of dark matter in the universe
Image used for illustrative purpose. Photo: WAM
Washington: Scientists have shared a new and very clear map that shows where dark matter is spread across the universe. The map was made using powerful images from the James Webb Space Telescope and helps people understand more about the unseen matter that makes up most of the universe.
Everything we can see, like stars, planets, animals and people, is called ordinary matter. But this kind of matter makes up only about 15 percent of all matter in the universe. The rest is dark matter. Dark matter cannot be seen because it does not give off light or reflect it.
Even though dark matter is invisible, scientists know it exists because of how it affects things around it. It helps hold galaxies together, changes how fast they spin, and bends light coming from faraway galaxies. This bending of light is called gravitational lensing.
Using this light bending effect, scientists studied about 250000 distant galaxies. By carefully measuring how their shapes were slightly stretched, they were able to find where dark matter is located between Earth and those galaxies.
This new dark matter map is much better than earlier ones. It is sharper, covers a larger area of space, and looks farther back in time. The map shows what the universe looked like around 8 to 10 billion years ago, which was an important time when many galaxies were forming.
Earlier dark matter maps were made using the Hubble Space Telescope. The new map is twice as clear and shows details that scientists could not see before.
The map also gives a clearer picture of the cosmic web. This is the large stracture of the universe made of galaxy groups, long dark matter paths called filaments, and wide empty spaces with very little matter.
The James Webb Space Telescope is much stronger than Hubble and can see faint and distant objects more clearly. This helped scientists use many more background galaxies to build a better map.
The area studied is known as the Cosmic Evolution Survey, or COSMOS. It lies in the direction of the Sextans constellation. Scientists say this new map will help with many future studies and bring new answers about how the universe grew and changed over time.
