Webb’s Scientific Method

Right now, the NASA/ESA/CSA James Webb Space Telescope is in space capturing spectacular images and spectra of objects in the Universe. All of these data reside in the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute (STScI), the science operations centre for Webb. A copy is also held at the ESA JWST Science Archive to provide quick access for European astronomers. However, it takes time for these exciting new observations to make their way from raw data to published, peer-reviewed science.

Peer Review

Scientific peer review is a long-established, quality-control system; new scientific discoveries are scrutinised by experts before they are published in a journal. The peer review process begins when a scientist or group of scientists completes a study of a particular object in the sky and then submits their written findings to an accredited journal for publication. The journal’s editors will then circulate the article to other scientists within the same field to gather their views and feedback. Only articles that meet good scientific standards, acknowledging and building upon other known work, make it through this process to be published in the journal. This peer review process is relied on to ensure the quality and accuracy of scientific results before they are shared with the public.

Since Webb’s discoveries are so new, time is needed for them to be vetted by the peer review process, and a pipeline of articles under peer review is growing as the telescope continues to make observations from its first year of planned science. This pipeline of articles will feed future Webb news as scientists with peer reviewed articles submit their findings to the STScI news office and ESA/Webb science outreach team to be considered for promotion.


Many Webb investigators, however, are also taking advantage of the way that the scientific publication landscape has changed in the last decade. They create draft papers that are sometimes publicly posted as “preprints” before the full peer review process is complete. This previewing stage allows for discussion within the science community, and researchers sometimes use this feedback to improve their written papers before they formally submit to a journal. At this stage, papers, imagery, figures, and initial analyses are public, but not yet considered part of the fully peer reviewed scientific literature.

ESA/Webb, in collaboration with NASA and STScI, as well as the science community, may share some imagery or spectra from papers prior to peer review, as well as images from Webb data publicly available in the MAST archive. Results that are shared while they are still awaiting peer review will be labelled appropriately to describe where in the process they are. Important scientific conclusions and discoveries from these images will be shared later, after peer review.