In terms of a total solar eclipse I agree with Gerald it would be just a few seconds before totality. The exact time depends on the eclipse and the relative sizes of the sun and moon. Even then, the scattered light from outside totality would alter things. I have programmed some empirical formulae to get the sun's brightness depending on the eclipse magnitude (fraction of solar diameter covered), and the relative sizes of sun and moon. I'll try and locate them.

There would also be a time during daily twilight (say on a clear day) when the overall illumination of the ground would be 1/1000th of daytime. I'm guessing it would be about 30 minutes after sunset, with a solar elevation of -6 degrees.

The window experiment also sounds interesting. On a clear day the sky (without direct sunlight) has roughly 10% of the sun's light over the hemisphere. That would be over 20000 square degrees. Therefore if you have a window showing 200 square degrees of sky and no direct sun it might work. The diameter of the window would be about 15 degrees then, so one could stand about 4 times the width of the window away.

...yet another way to look at it: about as bright a full moon expanded to around 8 degrees in diameter.

I moved a bunch of posts to this thread from the old main NH thread.

This thread will be the main thread for what remains of NH's cruise phase (an amazingly short time really, I feel as if NH was recently launched but there are now almost 9 years since it was launched).

Today's awesome PPOD pic is at http://www.boulder.swri.edu/ppod/

Soon you can sign up for push notifications....

And EVEN BETTER! Here's Amanda's latest Postcard from Pluto! http://plutopostcards.tumblr.com/post/9817...itous-things-to …

Enjoy!

PPOD/Pluto Picture of the Day now has an indexed archive! http://guinan.space.swri.edu/nhepo/archive_index

PPOD now allows you to sign up for push notifications. http://www.boulder.swri.edu/ppod/

Hey Alan, you've indicated before that the data from the Pluto flyby in July 2015 will trickle in slowly. Will we still get to see high res images come in as the approach happens or will we have to wait a bit?

I read an interview (somewhere, don't have the link on me!) where the plan is basically that some images from around CA (those worthy of being under the newspaper headlines) are going to be given priority in the downlink sequence. So although it will take ages to get everything down, there won't be a second agonizing wait for the best stuff after July.

Every LORRI image that comes to the ground will be posted to see, with <24 hour delay. (LORRI is the hi-res imager). That will include the very best images we have at P-2 and P-1 days. After C/A, more and more will be downlinked as the bird spends increasing time downlinking v. gathering data. The full data downlink will take 16 months, but you will be along for the ride with us on approach, and on departure.

Interesting to see the PPOD 9/28 artist view, in light of the earlier discussion of the 1/1000 Earth illumination appearance.

http://guinan.space.swri.edu/nhepo/archive/2014/09/28

One might consider some of the assumptions of atmospheric parameters that would go into such a visualization. This includes optical depths of gas and aerosols, as well as their scale heights. The vantage point of the viewer above the mean terrain height helps the depiction of the surface haze layer.

Awesome, thank you. I can't wait!

Reddit AMA with the New Horizons team, - Q&A by Alan Stern et al. with space enthusiasts

http://www.reddit.com/r/IAmA/comments/2igk...s_new_horizons/

This is the first of 10 Infographics being produced for the mission in 2015, thought UMSFers would like seeing it hot off the press!

Looks great Alan! Getting so excited to see Pluto and Charon and the rest of the gang in the windshield.

Very nice, Alan. Thank you for sharing.

What blows my mind, is that, I don't think most people realize that we will be the first humans to ever see Pluto. Man, just thinking about that is crazy.