Two Milky Way spiral arms are farther away than previously thought (heise.de)

• Distance correction of up to ten percent for two spiral arms
• Method: X-ray reflection from interstellar dust clouds
• Future NewAthena telescope will enable more precise mapping

"An analysis of data from the XMM-Newton and Chandra space telescopes shows that the Outer Arm and the Outer Scutum-Centaurus Arm of the Milky Way are up to ten percent farther from Earth than previously estimated. The correction is based on measuring X-rays reflected by dust clouds in the spiral arms. The results were published in Astronomy & Astrophysics and require an update of our galaxy map."