Can counterspelling be assensed?, Either before or during? Options

[Moon-Hawk]

Gosh, the topic title says it all. Can an astrally perceiving magician tell if someone is protected by counterspelling, and adjust their tactics accordingly before casting any spells? If no, then what about when they cast the spell, can they see the counterspelling if it's actively defending against their spell? What about someone else's spell?

Related question. Does a counterspelling magician know if someone they are protecting is targeted with a spell? Counterspelling is described as jamming ambient mana, or something like that, so based on that description it doesn't seem like they would.

Thanks.