The first detection of Pluto in X-rays has been made using Chandra in conjunction with observations from the New Horizon spacecraft as it approached and then flew by the dwarf planet in 2015. During four observations, Chandra detected low-energy X-rays from the small planet due to interactions between Pluto's atmosphere and a wind of particles from the Sun. The main panel in this graphic is an optical image taken from New Horizons on its approach to Pluto, while the inset shows an image of Pluto in X-rays from Chandra (not to the same scale). This result offers new insight into the environment surrounding the largest and best-known object in the Solar System's outermost regions. Scale: X-ray image is about 12 arcsec across (about 285,000 km).
X-ray: NASA/CXC/JHUAPL/R.McNutt et al; Optical: NASA/JHUAPL