New Pluto images discussed Options

[tedstryk]

They will likely be somewhat poorer in spatial resolution, since Hubble has no instrument on par in terms of spatial resolution with ACS HRC (repair not successful) and the long-since-removed FOC, the purpose will be monitoring change.

[AndyG]

A HUGE discovery, Pluto unveiled, at last, we've all got front row seats, and you're not happy?

This is more dress circle I think. However, we've all booked the real front row seats - though we don't get them for five years.

Andy

[tasp]

About 70 days out.

Appreciate that very much. Is the correlation between resolution and magnitude similar? In other words, is the NH camera capable of exposure times and sensitivity to see objects as faint as Hubble from 70 days out?

Maybe there are other satellites besides Nix and Hydra, perhaps larger, but much darker . . . . .

[Greg Hullender]

http://www.dailymail.co.uk/sciencetech/art...arf-planet.html

Pluto has a yellow-orange what..?

I suspect they meant "hue" not "hut," but the possibility that there's a Howard Johnson's restaurant up there is hard to rule out. After all, there's one on the Space Station in the movie 2001.

--Greg :-)

[tedstryk]

Also, there was a set taken with WF/PC2 and NICMOS in 2007. There is hope of a lower quality albedo map from the WF/PC2 data, although I don't know if this has been successful, but this would be another step in change monitoring.

[elakdawalla]

I think Buie mentioned during the briefing that it wasn't possible to make this sort of map with the WPFC2 data. I know he said he didn't expect to do so with the WFC3 data.

[tedstryk]

Quoting the abstract for the WFC3 observations, "A second goal of this program will be to retrieve a new epoch of albedo map for the surface of Pluto." With its high SNR and slightly better pixel resolution, it may be able to produce a new map.

[tedstryk]

It is worth noting that there was some darkening observed between 1994 and 1996, so it appears that this is a continuation of the process.

These are the maps from 1994 compared to those made in 1996 for "Live from the HST" (a K-12 program).

BTW, Other than the fact that I participated online in "Live from the HST" chat/discussion sessions(I was in high school at the time), I have nothing to do with these images.

[nprev]

Guess the big question here is whether we're seeing effects from outgassing, or condensation of the atmosphere, or both.

If it's atmospheric 'freezing' (probably the most likely explanation), why are the presumed deposits so globally asymmetrical? Lots of interesting questions to be answered, actually; NH may have happened at precisely the correct time to do so.

[hendric]

I think the slightest albedo difference would tend to accelerate and cause differentials like Iapetus. As the planet gets farther away, the brighter locations cool down first and get more frost first.

[nprev]

Ah! Yes, true; interesting how such a recent discovery dovetails with this.

Iapetus' albedo difference is quite symmetrical, though, unlike Pluto's. Still could very well be a similar mechanism at work. Pluto has a rotation period of something like 6+ days, plus the pronounced elliptical orbit; wonder how much 'mixing' happens just from that, local terrain differences aside.

[ngunn]

I think the slightest albedo difference would tend to accelerate

Exactly what I was thinking. Picture different regions with different underlying albedos/textures covered in thin (partly transparent?) 'frost'. When clearing starts in a particular region the whole patch goes relatively quickly, redistributing that material to cooler regions and thus delaying the onset of clearing there - until continued seasonal warming makes the next patch go critical. Throw in the really wide seasonal temperature range expected and a multiplicity of differently coloured volatile materials and the field of possibilities seems plenty wide enough to contain these observations. It does beg the question of how complete an understanding of Pluto the severely time-limited NH observations will allow.

[Webscientist]

Why are the presumed deposits so globally asymmetrical?

That's the best question we could ask here, I think!

I would answer with new questions: is it fully related to the changing atmosphere (condensation, sublimation phenomena...) or is it mainly related to an internal activity?

I've always thought that Pluto could'nt be classified as a normal planet due to its physical configuration. Let's recall that the relatively big moon Charon is only 19000 km from Pluto and that the center of mass is outside the sphere of Pluto.
As a result, we should set a special focus on the potential tidal forces from thre second Body.

Is Charon tidally-locked to Pluto?

[Phil Stooke]

Charon and Pluto are tidally locked.

Regarding explanations for the albedo patterns, presumably any model also should apply to Triton, which provides a bit of a test.

Phil

[tedstryk]

Yes, although Triton has much more subdued albedo patterns. HST mapped it with FOC in 1996 and with ACS in 2005 (results are still being worked on). It also took an extensive set of Triton data with STIS in 1999.