This was sent in by Gary – https://spaceweather.com … and click on May 10th and then, view … apparently, according to Dr Tony Phillips, May 9th, the biggest comet in the solar system is actually a planet. I'm not sure if that was meant tongue in cheek but it caught Gary's attention. Researchers have known for years that Mercury had an enormous tail. Now we have a photograph – at the link above. The source of the tail seems to be Mercury's very thin atmosphere – as in almost non-existent. Escaping gases fromthe atmosphere form a tail 24 million kilometres in length. There are several elements in the tail, and sodium is a prominent one of them. Sodium scatters blue light.
At https://phys.org/news/2021-05-reveals-hidden-hearts-large-stars.html … new research reveals hidden processes at work in the hearts of large stars. These are the chemical facories of the universe, it is thought, fusing hydrogen into helium [one of the ideas].
On a similar theme, at https://phys.org/news/2021-05-supermassive-black-holes-devour-gas.html … x-ray telescopes have captured images of a very bright intense light forming and subsiding in a faraway galaxy and concluded that a black hole had swallowed a passing star.
At https://phys.org/news/2021-05-planets-mystery-universe-worlds.html … shrinking planets. The idea is to explain missing data. Not enough middle sized planets have been discovered in other solar systems. Mini-Neptunes leaking gas.
At https://phys.org/news/2021-05-supernova-remnant-g5341003.html … a supernova remnant in the process of being investigated.