APOD: Fly Over Pluto (2015 Jul 18)

Comments and questions about the APOD on the main view screen.
User avatar
BMAONE23
Commentator Model 1.23
Posts: 4076
Joined: Wed Feb 23, 2005 6:55 pm
Location: California

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by BMAONE23 » Mon Jul 20, 2015 3:01 am

GiacomoFalcucci wrote:Dear All,

Good morning!
What stunning images!!

Who casts the shadows in Norgay region?
Is it the Sun or Charon?

Thanks and best

G
all the Light in the image comes from the sun and the shadows are cast by the mountains blocking that sunlight

starsurfer
Stellar Cartographer
Posts: 4781
Joined: Thu Mar 15, 2012 7:25 pm

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by starsurfer » Mon Jul 20, 2015 3:52 pm


madtom1999
Ensign
Posts: 76
Joined: Mon Jan 12, 2009 11:21 am

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by madtom1999 » Tue Jul 21, 2015 6:58 am

OK Tombaugh region has to be an impact crater on the left with ejecta moving out to the right up and down. I've a feeling this was some large slow moving object that made a splash but also a slump/wave of ice that formed the mountain ranges as well.
The polygonal patterns in the flat plain area are just convection cells from the cooling and freezing of the lake left after the impact.

User avatar
Chris Peterson
Abominable Snowman
Posts: 16669
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by Chris Peterson » Tue Jul 21, 2015 1:20 pm

madtom1999 wrote:OK Tombaugh region has to be an impact crater on the left with ejecta moving out to the right up and down. I've a feeling this was some large slow moving object that made a splash but also a slump/wave of ice that formed the mountain ranges as well.
The polygonal patterns in the flat plain area are just convection cells from the cooling and freezing of the lake left after the impact.
An impact on solid ice or an ice/rock mixture doesn't leave a lake. That scenario is only plausible if the crust is very thin and there's a liquid sea underneath. Possible, but still not known.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

madtom1999
Ensign
Posts: 76
Joined: Mon Jan 12, 2009 11:21 am

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by madtom1999 » Tue Jul 21, 2015 3:42 pm

Perhaps not a lake but I can imagine the shocked ice forming a slush that would take a while to solidify.

User avatar
Chris Peterson
Abominable Snowman
Posts: 16669
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by Chris Peterson » Tue Jul 21, 2015 7:10 pm

madtom1999 wrote:Perhaps not a lake but I can imagine the shocked ice forming a slush that would take a while to solidify.
I doubt it. If the impact is in solid material, most of it will be ejected. Even if there's slush in the bottom, we're going to be left with a crater, not a plain.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Pianosorplanets
Ensign
Posts: 31
Joined: Tue Jul 14, 2015 1:34 pm
Location: Pennsylvania, USA

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by Pianosorplanets » Tue Jul 21, 2015 8:45 pm

I would bow to Chris' wisdom on this. I would ask him one quick thing, if he has a moment to reply. It may not be possible so far out and in such coldness but I wonder if the friction of impact could potentially cause any amount of temperature increase leading to liquefaction or, at least, a lessening of the hard nature of the ices that could be permit an impact area to developing a mare type of appearance? Or is it just too, plain cold out there for such things?
It takes a lot of stars to make a piano.

User avatar
Chris Peterson
Abominable Snowman
Posts: 16669
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by Chris Peterson » Wed Jul 22, 2015 1:06 am

Pianosorplanets wrote:I would bow to Chris' wisdom on this. I would ask him one quick thing, if he has a moment to reply. It may not be possible so far out and in such coldness but I wonder if the friction of impact could potentially cause any amount of temperature increase leading to liquefaction or, at least, a lessening of the hard nature of the ices that could be permit an impact area to developing a mare type of appearance? Or is it just too, plain cold out there for such things?
I'm sure that an impact produces melting, and even in the near vacuum some liquid will persist for a bit. But what I'd expect would be a fairly typical crater, with some evidence of that melt on the walls and bottom. But we don't see craters at all. So the options are that there hasn't been cratering (which seems unlikely), or the surface has been remodeled fairly recently.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
geckzilla
Ocular Digitator
Posts: 9171
Joined: Wed Sep 12, 2007 12:42 pm
Location: Modesto, CA

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by geckzilla » Wed Jul 22, 2015 1:12 am

Have you seen the latest image? Craters are plentiful in the dark region of the new picture.
http://www.nasa.gov/press-release/nasa- ... or-july-24
Just call me "geck" because "zilla" is like a last name.

User avatar
Chris Peterson
Abominable Snowman
Posts: 16669
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by Chris Peterson » Wed Jul 22, 2015 1:50 am

geckzilla wrote:Have you seen the latest image? Craters are plentiful in the dark region of the new picture.
http://www.nasa.gov/press-release/nasa- ... or-july-24
Yes, and even in some of the earlier pictures. But I wouldn't say "plentiful". Nevertheless, this supports the idea of resurfacing rather than a lack of impacts. It's just that the resurfacing process isn't uniform over the entire surface.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
geckzilla
Ocular Digitator
Posts: 9171
Joined: Wed Sep 12, 2007 12:42 pm
Location: Modesto, CA

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by geckzilla » Wed Jul 22, 2015 3:16 am

I think a lot of details have been lost during compression. It seems especially bad where the craters are. Only the ones with high contrast light material seem to be outlined. It will be nice to look at the uncompressed imagery when it comes in to see if there are any low-contrast craters in there.
Just call me "geck" because "zilla" is like a last name.

User avatar
BMAONE23
Commentator Model 1.23
Posts: 4076
Joined: Wed Feb 23, 2005 6:55 pm
Location: California

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by BMAONE23 » Wed Jul 22, 2015 3:42 am

This image of Enceladus shows a fairly well cratered region near the southern pole Tiger Striped region. On an icy body with a probable ocean below

User avatar
BMAONE23
Commentator Model 1.23
Posts: 4076
Joined: Wed Feb 23, 2005 6:55 pm
Location: California

Re: APOD: Fly Over Pluto (2015 Jul 18)

Post by BMAONE23 » Wed Jul 22, 2015 3:49 am

geckzilla wrote:Have you seen the latest image? Craters are plentiful in the dark region of the new picture.
http://www.nasa.gov/press-release/nasa- ... or-july-24
This would be the area that has been dubbed "The Whale" at the area where the Whales Head meets the Heart
This area also reminds me of Iapetus