Following the completion of critical mirror alignment steps, NASA’s James Webb Space Telescope team expects that Webb’s optical performance will be able to meet or exceed the science goals the observatory was built to achieve.
On March 11, the Webb team completed the stage of alignment known as “fine phasing.” At this key stage in the commissioning of Webb’s Optical Telescope Element, every optical parameter that has been checked and tested is performing at, or above, expectations. The team also found no critical issues and no measurable contamination or blockages to Webb’s optical path. The observatory is able to successfully gather light from distant objects and deliver it to its instruments without issue.
After completing two more mirror alignment steps, we've confirmed the James Webb Space Telescope’s optical performance will be able to meet or exceed the science goals the observatory was built to achieve! Read more about this here.
While the purpose of Webb’s latest image was to focus on a bright star and evaluate the alignment progress, Webb’s optics are so sensitive that galaxies and other stars can be seen in the background. We started our alignment process with 18 scattered dots — 18 reflections of the same star, one from each of Webb’s primary mirror segments. These dots were then re-arranged, stacked, and fine-tuned by making small movements on the motors in the back of each mirror segment. This process continues to set the stage for our first science images this summer.
Red is the new black (& white)! The red color palette of Webb’s image was chosen to optimize visual contrast in the image, but did you know that Hubble and Webb actually record light in black and white? They use filters that allow only a specific color of light through, then the filtered images are individually colored by scientists and image processors, and combined into a full image. Colors in space telescope imagery sometimes recreate the way our eyes see; other times they’re selected to highlight interesting features of an object, such as different elements in a nebula. (Learn more about this here.)
Image Credit: NASA/STScI