Re: Planet X: Viewing WHEN?

Jeff Polston wrote in message <[email protected]>
>
> Thanks IMO.  I've been using astronomical dawn because that's what my
> computer programs give me.  But now I'll probably start using nautical
> dawn.
>
Although nautical twilight is still not that dark. We just get to nautical
twilight in the UK at this time of year - the Sun gets to a minimum altitude
of 12.4º below the horizon tonight. The sky is still visibly dark blue. It
looks kind of like the sky does when the Moon is full. I've taken a 5 minute
exposure under this light. It looks as though it was taken in broad
daylight.

Ric