Astronomers using the James Webb Space Telescope (JWST) have created an impressive map of dark matter. This map covers a vast area, including about 800,000 galaxies. Dark matter is intriguing because it doesn’t emit or absorb light, making it nearly invisible. This means it’s not just regular matter, which consists of protons, neutrons, and electrons. In fact, dark matter is believed to outweigh normal matter by a ratio of five to one.
Despite being invisible, dark matter does have a gravitational influence. It shapes the structure of the universe and affects how light travels. This phenomenon, known as gravitational lensing, was predicted by Albert Einstein in 1915. By studying these effects, scientists managed to use the JWST to produce a detailed map of dark matter.
The JWST focused on a region in the constellation of Sextans, roughly 2.5 times the size of the full moon. Over about 255 hours, it analyzed this area using its Near-Infrared Camera (NIRCam). This observation is part of a larger effort known as the Cosmic Evolution Survey (COSMOS), which involves around 15 telescopes, including the Hubble Space Telescope. These instruments help scientists investigate galaxy formation and the role dark matter plays in it.
Interestingly, Hubble had previously studied this same region in 2007. However, the JWST’s advanced sensitivity allowed it to detect about ten times more galaxies than Hubble could, and twice as many as any ground-based telescope might observe. This improved detail is changing how we understand the universe.
To create the dark matter map, astronomers used “weak gravitational lensing.” This technique measures the slight bending of light from distant galaxies as it passes through the warped space created by dark matter. Additionally, by employing another instrument, the Mid-Infrared Instrument (MIRI), researchers could better gauge the distances to the observed galaxies.
This new dark matter map is a significant step in our exploration of the cosmos. It highlights the JWST’s ability to transform our understanding of both nearby and distant space, offering fresh insights into the universe’s most mysterious components.
According to the latest reports, dark matter continues to be a hot topic in astrophysics. A 2023 survey indicated that the majority of astrophysicists believe understanding dark matter is essential for unraveling the universe’s origin and structure. These insights from the JWST underline the importance of ongoing research in deciphering the universe’s mysteries.
