Pluto Surface Observations 1: NH Post-Encounter Phase, 1 Aug 2015- 10 Oct 2015 Options

[Gennady Ionov]

Regarding NH's trajectory, if I remember correctly the flyby didn't occur at exactly the planned time (off by some seconds but well within the required accuracy) and this makes it more tricky to use the metadata to accurately determine the viewing geometry (especially in the hi-res images) until an updated trajectory (SPICE kernels) becomes avvailable.

At first I tried to use the data from
http://ssd.jpl.nasa.gov/horizons.cgi#top
but I found that the position of NH was displaced approximately 120 seconds, so I used the least squares method (with using distances to Pluto, Charon, Nix and Hydra up to 2,000,000 km) to made a correction of 3D position (about 1,665 kilometers) and velocity vector (about 11.6 m/s) so that the simulated distances become coincide to metadata with an error of about 0.1 km.

[MichaelJWP]

Hi all, I rarely post, but had a question on this amazing mission for those more knowledgeable.

When I look at the excellent simulation in "Eyes", I can see that at approx 15 mins. before closest approach, Charon "sets" behind Pluto", then at 9 minutes, it rises. Eyes doesn't show any photos taken at all of these events, in fact NH doesn't appear to be pointing at anything. These would have not only made dramatic pictures, but presumably at the Charon-rise point would highlight features on the limb?

Am I missing something (probably), or would these images have been of no value?

[Gennady Ionov]

Michael, I, too, for a long time the question arose.
As specially missed Charon set, while Pluto was carried out for all the cameras shooting Charon was behind, ahead of Charon, and its rise is also not hit in images.

[nprev]

Imaging this was suggested several years ago, but I don't know if it actually happened. Priority obviously had to be given to high-value science data acquisition at that time so I really doubt that made the cut.

[Gennady Ionov]

What kind of scientific data loss can be a question if deviation on Charonset

is 133 seconds, and at Charonrise

just 50 seconds?
Judging by the nature of scanning at once by RALPH, LORRI and Alice, the images of Charonset and Charonrise were obtained. Just NASA's Eyes bit not exactly show the real program running by NH.
Due to the motion of Charon relative Pluto while TDI of MVIC camera Charon could slightly smeared. But this adds even natural tableau.

[MichaelJWP]

...Judging by the nature of scanning at once by RALPH, LORRI and Alice, the images of Charonset and Charonrise were obtained. Just NASA's Eyes bit not exactly show the real program running by NH.

I hope so - I'm thinking of the Apollo 8 earthrise shots; ok, it's not the Earth, but NASA needs all the publicity it can get if it is to keep and hopefully increase the budget for continuing exploration.

[scalbers]

Imaging this was suggested several years ago, but I don't know if it actually happened. Priority obviously had to be given to high-value science data acquisition at that time so I really doubt that made the cut.

Indeed, weren't "Kodak moments" discussed on this forum to help the NH Team with image planning?

[Bjorn Jonsson]

I hope so - I'm thinking of the Apollo 8 earthrise shots

This would have been difficult due to the narrow field of view of NH's cameras.

[djellison]

just 50 seconds?

The uncertainty of the C/A time in the week leading up to the flyby was more than that.

That should basically answer your question.

[Gennady Ionov]

This would have been difficult due to the narrow field of view of NH's cameras.

MVIC (green rectangle) covers almost all Pluto disk and scans the very long image...

[elakdawalla]

AFAIK shooting these images was briefly considered but there was just too much going on near C/A; it would've cost too much valuable science at that moment.

In general, it was a lot harder to make "Kodak Moments" at Pluto than it was at Jupiter, because of the angle of approach -- recall that all the Jupiter Kodak Moments were mutual events, and those didn't happen from New Horizons' point of view on Pluto except for that one moment at C/A when it had other things to do.

[Gennady Ionov]

AFAIK shooting these images was briefly considered but there was just too much going on near C/A; it would've cost too much valuable science at that moment.

What is valuable science measurement might suffer if all the same, and the rising and setting of the whole fit into the one 8 minute scan, taken with a large margin (margin of 1 Pluto disc on both sides)?
On the contrary, picture of Charonset could provide additional information about the atmosphere of Pluto (Charon may have slightly dimming to near the edge of Pluto) and on the topography on the limb.

[nprev]

Lacking any direct knowledge, I cannot say for certain that such imagery was not acquired, but given the very tight window combined with the uncertainly in arrival times Doug mentioned as well as numerous other critical demands on the spacecraft during this period it is vanishingly unlikely.

If that was the NH team's judgement--as seems very, very likely--then that's the way it is, and we are not going to argue about it. Period.

[Explorer1]

We could always simulate the view at any rate, right? Once all the actually taken data is received and we have accurate hi-res maps of the appropriate areas, like in the Cassini thread when predicting which parts of a particular icy satellite getting a close flyby the next rev will be mapped.

[MichaelJWP]

We could always simulate the view at any rate, right? Once all the actually taken data is received and we have accurate hi-res maps of the appropriate areas, like in the Cassini thread when predicting which parts of a particular icy satellite getting a close flyby the next rev will be mapped.

Once mapping is complete we can indeed simulate any such view with a simple setup.

I raised the original question about the Charon-set/rise images, and although disappointed, I'm quite happy the the science team has decided there are greater priorities. Famous images such as Pale Blue Dot or the Day the Earth Smiled have only been gathered when all primary science has been completed.

A spacecraft in orbit is a completely different case to a fly-by such as this, which is a one-and-only chance to grab as much science data as possible. All indications so far are that the bounty of information collected exceeds all expectations.