Searching for ‘Green Oceans’ and ‘Purple Earths’

The early stage of giant telescope development involves a lot of horse-trading to try to appease all the different stakeholders that are hoping to get what they want out of the project, but also to try to appease the financial managers that want to minimize its cost. Typically this horse-trading takes the form of a series of white papers that describe what would be needed to meet the stated objectives of the mission and suggest the type of instrumentation and systems that would be needed to achieve them. One such white paper was recently released by the Living Worlds Working Group, which is tasked with speccing out the Habitable Worlds Observatory (HWO), one of the world’s premiere exoplanet hunting telescopes that is currently in the early development stage. Their argument in the paper, which is available in pre-print on arXiv, shows that, in order to meet the objectives laid out in the recent Decadal survey that called for the telescope, it must have extremely high signal-to-noise ratio, but also be able to capture a very wide spectrum of light.