Map pinpoints location of invisible dark matter

WHERE THE MATTER LIES This new map of dark matter covers an area about 700 times as large as the full moon as viewed from Earth’s surface. Areas with relatively little dark matter are blue; regions with a lot are yellow and red. The gray dots indicate the locations of known galaxy clusters, with the size of the circle representing the cluster’s mass.

Dark Energy Survey

By Andrew Grant

April 14, 2015 at 3:05 pm

BALTIMORE — Dark matter can’t be seen, but a new map shows where it’s hiding. Released April 13 at a meeting of the American Physical Society, the map confirms that the mysterious matter is concentrated in regions that contain a lot of ordinary matter in the form of galaxy clusters.

Scientists with the Dark Energy Survey created the map by scanning a large swath of sky with a 570-megapixel camera hooked up to a 4-meter telescope in Chile. Although dark matter doesn’t absorb, emit or scatter light, the researchers inferred its distribution by charting how its gravitational influence altered the paths of light zooming past. The map enables scientists to study dark matter’s role in influencing whether particular areas of the cosmos lit up with stars and galaxies or remained relatively empty.

The project’s ultimate goal is to use five years’ worth of sky scans to probe dark energy — a mysterious entity separate from dark matter that is causing the universe to expand faster and faster.