>Astronomical radio images are naturally overwhelmingly sharper than optical images, because radio telescopes today can have much larger apertures than optical

>Astronomical radio images are naturally overwhelmingly sharper than optical images, because radio telescopes today can have much larger apertures than optical telescopes. They can be higher resolution with very long baseline interferometry but I wouldn't say they are naturally higher. If I'm reading the article correctly these were collected by the ASKAP telescope array in Australia which has a resolution of 30 arcseconds at 1.4GHz [1], which is only about twice as good as the human eye. [1] https://www.atnf.csiro.au/projects/askap/config.html#:~:text=The%20initial%20ASKAP%20configuration%20is,30''%20at%201.4%20GHz https://www.atnf.csiro.au/projects/askap/config.html#:~:text.... To your point, though, when VLBI is used they can get ridiculous levels of resolution. M87 was imaged at tens of microarcseconds of resolution, which is 4-5 orders of magnitude better than any optical telescope in operation today.