4 ms·

I'm curious as to how much of the planet (I know, I know it's been demoted) the craft will be able to "see". That is given the distance from the sun will it be

I'm curious as to how much of the planet (I know, I know it's been demoted) the craft will be able to "see". That is given the distance from the sun will it be draped in darkness, barely visible? I had a comic as a kid that had these really freaky cold aliens that lived on Pluto in very dim light conditions. That's my only reference point.

srl 15y ago
My understanding (which I got from an astronomer looking for moons) is that it'll be enough to get a clear look at major features on most (not all!) of Pluto's surface, but nothing spectacular. Realize that even today, we don't really know what Pluto looks like, so any knowledge is big knowledge.
- jarin 15y ago
  There are some images from Hubble: http://en.wikipedia.org/wiki/File:Pluto_animiert.gif http://en.wikipedia.org/wiki/File:Pluto_animiert.gif Pluto only fills up a few pixels on Hubble's camera, but it's possible over time to generate a rough image: http://www.boulder.swri.edu/~buie/pluto/mapstory.html http://www.boulder.swri.edu/~buie/pluto/mapstory.html
celoyd 15y ago
Astronomers drove digital imaging sensitivity, so I reckon they’ve got it worked out. Skimming http://arxiv.org/pdf/0709.4281v1 http://arxiv.org/pdf/0709.4281v1 , it looks like Ralph, the main visible-light camera, can distinguish between true blackness and a mere 3k photons per pixel, and at the margin can detect objects of magnitude 14. Coincidentally, that’s about the magnitude of Pluto from earth, and you can’t see it even with a small backyard telescope. So this instrument is less like a consumer camera and more like, say, night-vision goggles. This paragraph originally did the math for Pluto’s brightness wrong (thanks to atakan_gurkan below for pointing that out), so instead let me refer you to a short but interesting Metafilter thread on exactly this question: http://ask.metafilter.com/23197/Darkness-at-the-edge-of-town http://ask.metafilter.com/23197/Darkness-at-the-edge-of-town . One more factor – Pluto’s albedo is quite high. It reflects 0.5 to 0.66 of the light falling on it, as opposed to e.g. 0.14 for the moon (which is fairly dark in the scheme of things, but not at all hard to photograph; you can easily overexpose it in a grainless photo with a recent consumer DSLR). So: dim, yes, but still clearly visible.
- atakan_gurkan 15y ago
  Brightness drops off inversely proportional to the square of the distance, not square root. Still, I think there will be plenty to see. I am quite excited about this actually.
- boneheadmed 15y ago
  Fantastic replies. Thanks all. Very excited to see what's out there.

srl 15y ago

My understanding (which I got from an astronomer looking for moons) is that it'll be enough to get a clear look at major features on most (not all!) of Pluto's surface, but nothing spectacular. Realize that even today, we don't really know what Pluto looks like, so any knowledge is big knowledge.

jarin 15y ago
There are some images from Hubble: http://en.wikipedia.org/wiki/File:Pluto_animiert.gif http://en.wikipedia.org/wiki/File:Pluto_animiert.gif Pluto only fills up a few pixels on Hubble's camera, but it's possible over time to generate a rough image: http://www.boulder.swri.edu/~buie/pluto/mapstory.html http://www.boulder.swri.edu/~buie/pluto/mapstory.html

celoyd 15y ago

Astronomers drove digital imaging sensitivity, so I reckon they’ve got it worked out. Skimming http://arxiv.org/pdf/0709.4281v1 http://arxiv.org/pdf/0709.4281v1 , it looks like Ralph, the main visible-light camera, can distinguish between true blackness and a mere 3k photons per pixel, and at the margin can detect objects of magnitude 14. Coincidentally, that’s about the magnitude of Pluto from earth, and you can’t see it even with a small backyard telescope. So this instrument is less like a consumer camera and more like, say, night-vision goggles. This paragraph originally did the math for Pluto’s brightness wrong (thanks to atakan_gurkan below for pointing that out), so instead let me refer you to a short but interesting Metafilter thread on exactly this question: http://ask.metafilter.com/23197/Darkness-at-the-edge-of-town http://ask.metafilter.com/23197/Darkness-at-the-edge-of-town . One more factor – Pluto’s albedo is quite high. It reflects 0.5 to 0.66 of the light falling on it, as opposed to e.g. 0.14 for the moon (which is fairly dark in the scheme of things, but not at all hard to photograph; you can easily overexpose it in a grainless photo with a recent consumer DSLR). So: dim, yes, but still clearly visible.

atakan_gurkan 15y ago
Brightness drops off inversely proportional to the square of the distance, not square root. Still, I think there will be plenty to see. I am quite excited about this actually.
boneheadmed 15y ago
Fantastic replies. Thanks all. Very excited to see what's out there.