James Webb Space Telescope Feed Post

NGC 5468 (Webb NIRCam + Hubble WFC3)

Space is all about triple-checking your work. When it comes to how fast the universe is expanding, new and extended Webb measurements have reaffirmed the accuracy of @NASAHubble's calculations. According to Nobel laureate and researcher Adam Reiss, “[Webb has] now spanned the whole range of what Hubble observed, and we can rule out a measurement error…with very high confidence.” But why is the expansion rate so much faster than projected by the universe’s “baby pictures”? The source of this acceleration remains shrouded in mystery. Learn more about the puzzle of dark energy, and how future observatories could solve it: science.nasa.gov/missions/webb/nasas-webb-hubble-telescop... This image: This image of NGC 5468, a galaxy located about 130 million light-years from Earth, combines data from the Hubble and James Webb space telescopes. This is the farthest galaxy in which Hubble has identified Cepheid variable stars. These are important milepost markers for measuring the expansion rate of the universe. The distance calculated from Cepheids has been cross-correlated with a type Ia supernova in the galaxy. Type Ia supernovae are so bright they are used to measure cosmic distances far beyond the range of the Cepheids, extending measurements of the universe's expansion rate deeper into space. Image description: A face-on spiral galaxy with four spiral arms that curve outward in a counterclockwise direction. The spiral arms are filled with young, blue stars and peppered with purplish star-forming regions that appear as small blobs. The middle of the galaxy is much brighter and more yellowish, and has a distinct narrow linear bar angled from 11 o’clock to 5 o’clock. Dozens of red background galaxies are scattered across the image. The background of space is black. Image & Description by NASA