Enceladus Plume Search, Nov. 27 Options

[jmknapp]

Interesting item in the science plan kernel (S16) just released to the NAIF website:

OBSERVATION_ID: S1629

SEQUENCE: S16

OBSERVATION_TITLE: Plume Search

SCIENCE_OBJECTIVE: Hope to detect/observe plumes, whether from volcanic activity or geysers.

OBS_DESCRIPTION: Point and stare.

SUBSYSTEM: ISS

PRIMARY_POINTING: ISS_NAC to Enceladus (0.0,5.0,0.0 deg. offset)

REQUEST_ID: ISS_018EN_PLUMES001_PRIME

REQUEST_TITLE: ENCELADUS Geyser/Plume Search

REQ_DESCRIPTION: 1;ENCELADUS Geyser/Plume Search 1x1xNPp -- 3 different exposures

BEGIN_TIME: 2005 NOV 27 19:00:00 UTC

END_TIME: 2005 NOV 27 20:00:00 UTC

[Phil Stooke]

I can't help thinking that the Cassini folks really need to clear this up. Frankly, we're in rather poorly understood ethical ground here, because we are living through a transition in the way data are distributed.

The old idea was that NASA data were proprietory for a while to give the team who did the hard work to get the images the first chance to use them. Then it would be publicly available. That in itself was different from the more distant past, and other areas of science, where data might be proprietary for ever, basically.

But now the MER, Cassini etc. projects are releasing raw images almost as soon as they get them. The Mars Odyssey Themis team just started doing the same. Apparently MRO will as well.

(aside: NEAR said they would, but chickened out a few days before going into orbit... Calvin Hamilton and I were playing with the daily releases of images just like we are today with Cassini and MER, until it was shut off)

The catch is, the "raw data" are not really raw. Images are contrast stretched and heavily jpegged. Now, I may be wrong, but I have believed all along that when they say 'should not be used for scientific analysis until a validated copy is deposited in PDS' or words to that effect, what they mean is - it's full of jpeg artifacts and has no photometric validity, so you can't trust the pixel values. For instance, you can't calculate albedo or optical depth, and small details may be artifacts. I really don't think anybody intends that the images are totally out of bounds. In fact I think that would be unenforceable as well as just plain foolish.

But maybe we need clarification here. If the Cassini imaging team really don't want people doing anything scientific with the daily releases, they need to be specific about it on their website. If it's only the caution about pixel values they are intending, they could be more specific about that. But frankly, we live in an era where any one of us could discover a new satellite or whatever in these images, and there's nothing to stop that happening once the images are on the web. If the team really doesn't want that, they shouldn't put it out there!

Phil