Advanced mirror technology now powers a breakthrough X-ray telescope

Scientists in Japan have developed a high-resolution X-ray telescope sharp enough to distinguish an object just 3.5 mm wide from one kilometer away, by combining precision mirror-making technology with space astronomy. To test its performance, they built a first-of-its-kind evaluation system, capable of simulating starlight on the ground to measure the telescope's sharpness before its launch on the US-Japan FOXSI sounding rocket mission. The findings, published in Publications of the Astronomical Society of the Pacific, represent a landmark achievement for Japanese X-ray astronomy and pave the way for high-resolution X-ray observations on future smaller satellites.