How Are Webb’s Full-Color Images Made?
Taking a full-color photo is typically instantaneous. Many of us walk around with powerful cameras in our pockets—our smartphones. What may be less obvious is that the images smartphones take begin as binary code, long lists of zeros and ones known as bits. But we don’t see the binary code. Instead, a full-color image almost immediately appears on screen. For Webb’s cameras, a full-color image is not an instant second step. Why? Much of it is owed to their complexity as scientific instruments, which are far more advanced than those we point and shoot.
Let’s start by reminding ourselves of where this powerful observatory is located. Webb follows a halo orbit 1.5 million kilometers (1 million miles) from Earth. It’s not exactly nearby. Despite this, it takes only five seconds for Webb to send data to Earth. But those data aren’t delivered as an image. Instead, the data are transmitted to Earth in the form of bits. When the binary code hits “home,” at the Barbara A. Mikulski Archive for Space Telescopes (MAST), the bits are transformed into black-and-white images, and these unprocessed images are made available to the public quickly, unless there is a proprietary research period (typically one year).
How exactly is color applied to Webb’s images? Whether you are an astrophotographer, a researcher, or imaging specialist at the Space Telescope Science Institute (STScI), processing a Webb image is a human-centered process. Here, we detail how these images are made at STScI, including how Webb’s infrared light is mapped to the visible light our eyes can perceive.
