File:Hubble Is Paving Scientific Paths for NASA’s James Webb Space Telescope (37466224842).jpg

NASA’s Hubble Space Telescope is helping identify potential celestial targets for the James Webb Space Telescope through a series of preparatory science observations to be completed before Webb is ready to make observations of its own.

This preparatory science program began in 2016 in response to the desire of astronomers to use Hubble observations to set the stage for Webb. The program marked the first time astronomers were encouraged to submit science proposals for Hubble observations that could pave the way for Webb’s own observations. So far, 40 proposals have been approved.

Using multiple observatories to analyze the same objects can identify aspects of those objects that using one observatory alone cannot. Hubble was designed to primarily observe the universe through visible light (though it is also able to see into the ultraviolet and near-infrared), while Webb is specifically designed to observe the universe in infrared light, through both direct imaging and spectroscopy. Spectroscopy measures the spectrum of light, which scientists analyze to determine physical properties of what is being observed, including temperature, mass, and chemical composition.

Several preparatory science proposals in the program promise to use Hubble to deliver observational data Webb is not designed to collect. Hubble is able to see parts of the visible-light spectrum that Webb is not able to observe, and so it can fill potential observational gaps. For example, Hubble can examine exoplanets in light across the full electromagnetic spectrum available to it, with emphasis on the ultraviolet and blue wavelengths. Coupled with Webb’s infrared capabilities, both telescopes will deliver a more complete picture of the exoplanet systems.