In late May, NASA's STEREO-A spacecraft watched the comet's disintegrating remains dive past the Sun. STEREO-A's Heliospheric Imager is a sensitive camera that can see stars, planets and comets near the Sun. In the video you can clearly see the gaseous material blowing from the left. This is the solar wind. Yes, the Heliospheric Imager is so sensitive, it can even see the wind! "As Comet ATLAS moves away from the sun, it will technically be observable low in the sky from the southern hemisphere," says Karl Battams of the Naval research Lab in Washington DC . "However, the comet had already fragmented by the time STEREO-A saw it, and it was fading even more by the time it left the Heliospheric Imager's field of view. Comet ATLAS is unlikely to be seen again other than by powerful telescopes." "In the images showing Mercury, you may also see an unusual feature," says Battams. "Mercury has a tail much like a comet. It is caused primarily by sodium atoms being kicked off Mercury's surface by intense sunlight."
https://youtu.be/5kL8gQ8teV0