Project Echoes (Celestia Content Rework) - Release 0.1

[FarGetaNik]

I'm happy to announce the release of my preliminary version of:

Project Echoes

It has a long history, in short at some point I decided the default catalogues of Celestia weren't good enough anymore and started working on a new default for Celestia. This project focuses on updating the solar system catalogues as well as updating textures and shape models.

It's still a work in progress but I had to make a cut somewhere and put it out before I get tangled in minor issues again that lead to long delays. I hope to update it again some time soon. For details, see the readme-PDF file in the base package.

You can download Project Echoes here.

[Lafuente_Astronomy]

Nice! Though if you want, you can coordinate with onetwothree and pirogronian to update the defaults for 1.7.0, and the possible 1.8.0 versions.

[Anthony_B_Russo10]

Cool.

[SevenSpheres]

Great work!

Edit: Why are Charon and Dysnomia defined as dwarf planets instead of moons?
Also, Vesta and Salacia aren't dwarf planets:

A 2012 analysis of Vesta's shape[59] and gravity field using data gathered by the Dawn spacecraft has shown that Vesta is currently not in hydrostatic equilibrium.[60][61]

Wikipedia wrote:
However, Grundy et al. argue that objects such as Salacia, in the size range of 400–1000 km, with albedos less than ≈0.2 and densities of ≈1.2 g/cm3 or less, have likely never compressed into fully solid bodies, let alone differentiated, and so are highly unlikely to be dwarf planets.[8]

(I can't make the second quote work...)

[fyr02]

SevenSpheres,

Dysnomia and Vesta definetly should be changed. Charon is debatable but that's an argument for another time.
Wikipedia also says about Salacia that "Salacia is large enough that it is unlikely to have a significant porosity and is likely differentiated."
of course the one you picked above was Grundy's assesment, however, Brown consideres it "almost certainly" and Tancredi assesses Salacia as "possible"

Grundy essentially argues that every tno smaller than Sedna excluding Orcus and Ixion(?high albedo) are not dwarf planets.
Brown and Tancredi dispute.

[FarGetaNik]

Oh dear I didn't mean to spark that debate again. I got fed up with the IAU definition and did my own thing basically. I have a slightly different view on what should be a dwarf planet and what not (I don't even want to call it dwarf planet but explaining my reasons in detail will result in a page-long article) and classified those objects accordingly.

As for TNOs, I was kinda wary to not go crazy with every mid-sized TNO as I think the lower limit is actually much higher than most people assume (just look at Iapetus). Salacia seemed to be a good cut-off but newer data suggests it might be less likely to be a dwarf planet so what can you do.

Vesta was kinda subjective I have to admit, as Ceres alone in the asteroid belt didn't seem right and Vesta was in equilibrium when it formed but since has been disrupted.

And binary objects, it doesn't seem right to be to classify one component of a similar-sized binary as a planet/asteroid/dwarf planet what have you, and the other one as a moon, so that's why.

I suppose for a more official release of Project Echoes I should reclassify the objects according to IAU. Didn't expect to stirr things up that much.

[Art Blos]

In Celestia Origin I always adhere to the official classification. For example, it has long been obvious that the Gonggong (2007 OR10) is a dwarf planet, but so far it has not received status. We have this object listed as an asteroid.

However, if the author wanted to emphasize obvious things, this is his decision.

[FarGetaNik]

At this point I'm pretty sure 2007 OR10 will never be reclassified. The IAU has given up on announcing additional dwarf planets.

Oh well I can reclassify them according to IAU and make an addon for my personal use then.

[Art Blos]

At this point I'm pretty sure 2007 OR10 will never be reclassified. The IAU has given up on announcing additional dwarf planets.

Why do you think so? The fact that IAU did not raise this theme in recent assemblies does not mean that it issue is closed forever. Perhaps there is still insufficient evidence of hydrostatic equilibrium.

[FarGetaNik]

Perhaps there is still insufficient evidence of hydrostatic equilibrium.

That's the problem. Unless you send a spacecraft to every single object in question and measure its physical properties to prove equilibrium, the IAU wont accept it. At least that's the impression I got.

[Art Blos]

That's the problem. Unless you send a spacecraft to every single object in question and measure its physical properties to prove equilibrium, the IAU wont accept it. At least that's the impression I got.

For Haumea, Makemake and Eris this was not required.

[FarGetaNik]

Eris was way past the threshhold. Makemake and Haumea got slipped throug with the AbsMag 1 rule. There are no known objects that would pass in a similar fashion.

[Art Blos]

Eris was way past the threshhold. Makemake and Haumea got slipped throug with the AbsMag 1 rule. There are no known objects that would pass in a similar fashion.

Probably so. In any case, the emergence of new dwarf planets is only a matter of time.

[FarGetaNik]

It's been a decade. I lost my hopes in that regard. I'm considering a new definition is more likely at this point as planetary scientists don't agree with the IAU anyways...

[Art Blos]

It's been a decade. I lost my hopes in that regard. I'm considering a new definition is more likely at this point as planetary scientists don't agree with the IAU anyways...

My personal approach to such dilemmas comes down to a simple question - "who am I to argue with the world community?"
Many still do not agree to consider Pluto a dwarf planet (I was the same before). But in all official sources and scientific publications, it status is more than concrete. The same applies to TNO and Vesta.

But nobody canceled their personal choice.

[SevenSpheres]

And binary objects, it doesn't seem right to be to classify one component of a similar-sized binary as a planet/asteroid/dwarf planet what have you, and the other one as a moon, so that's why.

Fine with me for Pluto-Charon, but Dysnomia is probably not in HE.

Grundy essentially argues that every tno smaller than Sedna excluding Orcus and Ixion(?high albedo) are not dwarf planets.
Brown and Tancredi dispute.

I went with Grundy et al. because it's more recent.

[SevenSpheres]

FarGetaNik,

Asking for this. What are the licenses for the source images you used to make the M and T star textures? Also, can you make a Y star texture from free use sources?

[FarGetaNik]

SevenSpheres,

for M star textures I've been using images by the swedish solar telescope. All the copyright information I could find was this:

The images and movies found here are free for publication provided that proper credits are given.
Credits
Unless explicitly stated otherwise, all images were observed with the Swedish 1-m Solar Telescope (SST). The SST is operated on the island of La Palma by the Institute for Solar Physics in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

The Institute for Solar Physics is a national research infrastructure under the Swedish Research Council. It is managed as an independent institute associated with Stockholm University through its Department of Astronomy.

Please credit the telescope and the Institute for Solar Physics as well as the observers for the individual images. Observers come from our own staff as well as from many visiting groups.

I'm not sure what level of detail is necessary here.

The T star texture I'm using wasnt published with any license, it's simply a randomly generated texture by JVV he posted on the Celestial matters forum iirc.

As for a Y star texture, I really have nothing to go from there so any attempt by me making such a texture won't be statisfactory for anyone. Using any random fictional gas giant texture will do. Not even sure how to color it as Y dwarfs don't emmit any visible light (except a bit of red maybe that I'm not sure if it would be even perceivable).

Added after 10 minutes 56 seconds:
Alternatively, I also made a version of an M star texture from SDO images that i scrapped due to poorer quality:

[FarGetaNik]

I updated Project Echoes to version 0.2:

Download

Changes include implementing my new texture processing standard, improved atmosphere render and some minor updates to physical parameters and shape models of asteroids imaged by sphere.

[SevenSpheres]

After some feedback from the community, I changed the classification of various objects back to the official IAU classification.

Well, I'm fine with classifying Gonggong, Quaoar, Sedna, and Orcus as dwarf planets. Charon too, it's just semantics whether it's a dwarf planet or a moon.

Note that there is a bug in Celestia that randomly classifies barycenters so this only gets worse by this measure.

Why not report it on GitHub?