James Webb Space Telescope – Are They Pictures Or Images?

It is likely that you have witnessed the amazing capabilities of the James Webb Space Telescope (JWST) by now. This scientific and technical marvel means as much to humanity as it is does to the scientific community. Judging by the people talking about the telescope, it is clear to me that this is one of those scientific moments that transcends race, class, borders and cultural marinades. I am a weather and climate scientist but spent a significant portion of my career at NASA’s Goddard Space Flight Center. During that time, I interacted with experts associated with the Hubble Space Telescope and JWST. Many people have talked about the awesome “pictures” from JWST. Technically, they are images. Let me explain.

Honestly, in the grand scheme of things, I really does not matter what you call them. It is more important that we appreciate the meaningfulness of this scientific wonder. I tweeted earlier in the week that the products from JWST are not just about pretty images, and encouraged fellow scientists to provide “so what” when they share them. By doing so, we counter the narrow perspectives out there that ask, “why are we spending all of this money to take pretty pictures of space?” My previous Forbes piece lays out why JWST matters to all of us.

As an educator with a public platform, I often try to share information that you might not think about. For example, most people have a misunderstanding of what “percent chance of rain means” (explanation here) or think heat lightning is a thing (It’s not). As I shared with a friend recently that NASA refers to what you see as images when she posted about the “pictures.” I also realized that a teachable moment had reared its head.

Pichalab.com published a 2022 essay entitled, “Whats the difference between a photo, picture, and an image? According to the essay, “In simple words, the difference between a photo (short for photograph) and a picture is if it’s taken by the camera it’s a photo. A picture on the other hand can be a photo as well but be also a drawing or a painting.” The term image, according to the essay, has broader meaning. The essay goes on to say, “An image is an optical counterpart or appearance of an object, as is produced by reflection from a mirror, refraction by a lens, or the passage of luminous rays through a small aperture and their reception on a surface.” By the way, a saved photo file on your computer is an image.

Computerhope.com defines an image as, “Any visual object that’s modified or altered by a computer or an imaginary object created using a computer.” Ethan Siegel masterfully explains, in a Big Think essay, the image processing behind the first images released this week by NASA. To follow along with his explanation of the JWST, it is important to understand that the image processing for this space telescope is fundamentally rooted in the electromagnetic spectrum. According to NASA’s website, “Electromagnetic energy travels in waves and spans a broad spectrum from very long radio waves to very short gamma rays.” We see with our eyes using the visible (optical) portion of this electromagnetic spectrum.” The Hubble Space Telescope operates primarily in the optical and ultraviolet portions of the spectrum whereas JWST uses the infrared portion of the spectrum. The NASA JWST website explains that the infrared region is useful because, “In particular, more distant objects are more highly redshifted, and their light is pushed from the UV and optical into the near-infrared….observations of these distant objects (like the first galaxies formed in the Universe, for example) requires an infrared telescope.” A key point here is that JWST is a complementary to Hubble rather than a “replacement,” as NASA routinely reminds us.

Even within my field of meteorology, we use satellite imagery that exploits aspects of the electromagnetic spectrum to monitor hurricanes, tornadic storms, and other weather phenomena. We always refer to those products as images too, even though I have certainly heard people refer to them as pictures.