Thread by @NASAWebb

The 18 random dots featured in this video might not look like much, but they represent a big step forward in #NASAWebb’s 3-month mirror alignment process and its quest to #UnfoldTheUniverse: blogs.nasa.gov/webb/2022/02/1…

Let’s connect the dots with a thread ⬇️

⚫️ These dots confirm that Webb’s Near-Infrared Camera, or NIRCam, can collect light from celestial objects — and that starlight from the same star can be reflected from each of Webb’s 18 unaligned mirror segments back at Webb’s secondary mirror and then into NIRCam’s detectors.

⚫️ Our team first chose a bright, isolated star called HD 84406. Over ~25 hours, Webb was repointed to 156 positions around the star's predicted location, generating 1560 images with NIRCam’s 10 detectors. This is just the center of an image mosaic with over 2 billion pixels!

⚫️ Because the dots could have been spread out, the initial search covered an area about the size of the full Moon. Our team found light from all 18 mirror segments very near the center early in the search, closely matching expectations & simulations.

⚫️ Each dot visible is the same star as imaged by each of Webb’s 18 primary mirror segments. Here, you can see which dot corresponds to which mirror segment, including the dots taken by the segments on Webb’s mirror wings.

⚫️ Right now, as Webb is still getting into focus, you can think of Webb as an 18-eyed creature looking in 18 separate directions. A larger dot indicates that the segment is less focused than a smaller dot. A flatter, pancake-like dot indicates that a segment may be tilted. 🥞

⚫️ In the coming weeks, our team will align & focus each of these 18 dots, then stack the dots on top of each other to form a single point — one unified image from all of Webb’s 18 mirror segments. What’s ahead: blogs.nasa.gov/webb/2022/02/0…

Then, Webb’s images will only become clearer and more detail-laden as its instruments arrive at their intended operating temperatures and start capturing data. All of this will culminate in our spectacular first scientific images, expected this summer. #UnfoldTheUniverse