Free Astronomy Magazine July-August 2026

31 ASTRO PUBLISHING stellar scattering in the sky. At radio frequencies between about 1 and 5 GHz, the NSF VLBA’s continent-scale network of ten antennas reveals that the quasar’s image is not just blurred by this material but also peppered with fine substructure. These persistent, patchy distortions can only be explained by refractive scattering from turbulent plasma on scales roughly comparable to the size of our solar system. The NSF VLBA detections, which span obser- vations from 2010 to 2019, show that this turbulent “screen” in front of the quasar is remarkably stable over time, making TXS 2005+403 an exceptional radio laboratory for probing interstellar turbulence. These results will help astronomers better understand how energy cas- cades through the ionized gas be- tween the stars and how that turbulent gas affects some of the sharpest images in astronomy, in- cluding those of the Milky Way’s central black hole made by the Event Horizon Telescope. By charac- terizing how turbulence scatters radio waves along this line of sight, ongoing NSF VLBA campaigns through 2026 aim to refine models of the Cygnus scattering screen and improve techniques for correcting such distortions in future high - reso- lution radio images. JULY-AUGUST 2026 R adio light from quasar TXS 2005 +403 travels roughly 10 billion light-years to reach Earth, traversing the Cygnus region, one of the most turbulent and scattering environ- ments in the Milky Way Galaxy. On the left, this artist’s conception shows the quasar as it truly appears, with a bright accretion disk and jets blasting into the galaxy like a beacon through the darkness. On the right, we see how turbulent gas distorts scientists’ view of the quasar in much the same way heat haze from a fire warps our view of the objects behind it. In a new study led by astronomers from the Center for Astrophysics | Harvard & Smithsonian (CfA), scien- tists have for the first time directly detected how interstellar turbulence distorts light from a distant quasar, revealing the structure of that turbu- lence. [Mel Weiss/CfA] !