Origin of new emergent Coronavirus and Candida diseases–Terrestrial or cosmic?

It's not a new idea

https://en.wikipedia.org/wiki/Diseases_from_Space

The idea that life originated in a comet or asteroid is still as plausible as any origin of life. All the ingredients of an RNA world are there.

https://en.wikipedia.org/wiki/Murchison_meteorite

There could very well be asteroids with liquid water inside them: some are certainly warm enough, it just takes a "crust" able to hold in a bar of pressure to maintain it.

On the other hand, it is absolutely incredible that a virus living on an asteroid would grow a spike protein that fits

https://en.wikipedia.org/wiki/Angiotensin-converting_enzyme_...

which certainly evolved on Earth.