How can Mercury's sodium tail be imaged? I recently learned that Mercury has a sodium tail. Can this sodium tail be imaged with a ground based telescope? Is so, what is the minimum setup required to be able to take a picture of it? Do you need any specific filters?
Yes, it is possible; see https://twitter.com/sevospace/status/1328082050889490433
However, M. Voltmer used a “custom-made sodium filter,” without giving any details…