well the reports keep rollin in on the ml - a quick attempt at a summary and cherry pick of some posts by people like JBortle/A Hale and their take on it.
seems brightness steady/ still no tail/ last time it did this in 1892 at a similar distance (and came to be discovered) the outer coma eventually expanded to about .5d!! also last time it held its brightness at these levels for 2 or 3 weeks! and then underwent another smaller outburst around two months later.
as for composition/ i read a suggestion/loose theory from JBortle that structure could be honeycombed and its just a large sinkhole formed/ no danger to survival as it did the same over a hundred years ago, and is still around
