Pluto System Small Moons: NH Post-Encounter Phase, 1 Aug 2015- TBD Options

[alan]

Kerberos

[Gladstoner]

Nix:



https://www.nasa.gov/feature/last-of-pluto-...by-new-horizons

[stevesliva]

I missed the PR text accompanying the Kerberos image until today... It's interesting that they now believe it's less massive than expected, while predictions for the rest were relatively spot-on.

[stfletch]

Yup. I guess its possible that the interpretation of the gravitational "weighing" could still be correct if Kerberos is a lot denser than the other small moons, though that would be pretty unexpected and hard to explain in itself.

[ngunn]

It's re-enacting the story of Pluto. Pluto was discovered as a result of a targeted search for a presumed massive body perturbing the outer planets. It was found in the right place but turned out not to have the mass required. In the new as in the old case I imagine the calculations will be rerun to make presumed greater mass of Kerberos unnecessary, poor little thing.

[alex_k]

My processing of Kerberos, 4 images stacked, x16:

[nprev]

Looking at the apparent 'dumb-bell' shape of Kerberos it's tempting to speculate that this property combined with varied phase angles between observations may account for the size estimate & albedo errors in some way. Most such estimates assume a more or less spherical body for simplicity's sake.

[fred_76]

This is an attempt to colorize Nix using the previous color picture and the last high resolution posted today.

Not that easy because the angles of view are different. I distorded the color picture so that the main structures are surimposed between the images.



Fred

[Bill Harris]

apparent 'dumb-bell' shape of Kerberos it's tempting to speculate...

Don't 'spose it's a contact binary?

[nprev]

<shrug> Could well be. Doubt we can tell from NH data.

[Bill Harris]

Given that many small bodies have been observed to be bi-lobed or dumbell-shaped and the several that have been visited and seen to be contact binaries it's not to much a stretch to assume that Kerberos may be.

[Phil Stooke]

New images of Hydra today. This is a composite of the two images, enlarged 4x.

Phil

[alex_k]

My processing of Hydra 07/13 23:16 series, 3 images used, enlarged 6x.


[upd]
...and the series 07/13 04:13, 2 images, 8x.

[alex_k]

A very hypothetic attempt to find match between Hydra series.


From left to right:
07/13 04:13
07/13 23:16
07/14 07:40

[Bill Harris]

Given that many small bodies have been observed to be bi-lobed or dumbell-shaped and the several that have been visited and seen to be contact binaries it's not to much a stretch to assume that Kerberos may be.

Looks like the NH data suggests that they are contact binaries, or, on another scale, accretionary bodies:

New Horizons data indicates that at least two (and possibly all four) of Pluto's small moons may be the result of mergers between still smaller moons. http://pluto.jhuapl.edu/Multimedia/Science...mp;image_id=377


http://pluto.jhuapl.edu/Multimedia/Science...ergedBodies.jpg


--Bill