There are a number of ways this can be read. I will look at the poem’s references to LIGHT in this analysis. I may come back to it again in future.
“birches, inheriting the last light” – part of the description of December. I imagine an evening starting early.
“A comet that was lost should be visible at sunset” – The comet would presumeably have been “lost” in the day – as you wouldn’t be able to see it in the light?
“million tons of light/Like a glimmer of haws and rose hips” – a contrast between the reality of the vastness of the comet – and the rose pink way it should look to him when he sees it.
“Sometimes I see a falling star” – There are other things he sees, but he has yet to see the comet that he wants to see.
“If I could come on meteorite!” – He is keen to see the comet – it would be special and worth it.
“beautiful prismatic counselling” – I suppose he is the prism – they talk to him, and the advice is varied in tone and colour.
“the diamond absolutes”- ok so maybe this isn’t light – but it sparkles! This is a contrast to the prismatic counsel – these are ideas that are true becuase they have been around and under pressure for centuries. That’s what he is looking for (as well as the comet!)
“these sparks… meagre heat” – he has a wee fire there, but becuase he was focusing on his fire he hsd “missed / the once-in-a-lifetime portent,/the comet’s pulsing rose”
Again, the comet is “lost” because he is looking at a little fire near him.
The poem I think is about missing the thing you are looking for because of all the other minor things near you.
