We know that dark matter exists, but, irritatingly, we don’t know what it is.
One way to figure that out is to look for signs of it here on Earth, using subatomic particle detectors. But a new idea just published in a scientific journal is that we need to go bigger. A lot bigger: Using
entire exoplanets as detectors.
I give them points for thinking originally, for sure. matter directly. It affects the way galaxies rotate, the way galaxies behave in clusters, the way clusters affect the light of objects behind them, and a host of other things, too. We know it exists. And over the decades people have looked for it, but almost everything that could possibly work has been eliminated. It’s not teeny black holes, or rogue planets, or cold gas. Nothing made of normal matter works, leaving only “exotic” subatomic particles like axions as candidates. Attempts have been made to look for those, too, but so far zip.
Artwork showing the Nancy Roman Space Telescope, formerly the Wide Field Infrared Survey Telescope. Credit: NASA
This telescope is in the early stages now, with engineering models being built to test out the design. Scheduled for launch in the mid-2020s (which seems aspirational, but shouldn t be too long after that) and costing about $4 billion (including the first five years of mission costs), it s based on what NASA calls legacy hardware and concepts, ideas and tech developed for previous missions that have been shown to work.
Roman is very similar to the Hubble Space Telescope: It will sport a 2.4-meter primary mirror, the same size as Hubble s. But it will have a far, far wider field of view, meaning it will see larger chunks of the sky. How much bigger? In a single image it will see