The End of Earth - add-on is coming soon

[fsgregs]

Hi folks:

I am writing a new Educational Activity which teaches the reader about the life cycle of stars (including our Sun). It will take them through the many stages of a star's life, from a nebula to Main Sequence through Red Giant, white dwarf, etc. It will also cover larger stars and what happens to them (supernova, neutron stars, black holes, pulsars, etc.)

I'm excited about it and am developing a custom add-on for the Activity. In particular, I've created a scene far in the future, when our Sun has swollen to a Red Giant and is approaching Earth's orbital radius. The end is near for Earth, which has become semi-molten again with the oceans long boiled off. Here is a screen shot:




Once Earth is consumed, Mars survives but is also horrendously hot, with the Red Giant parked periously close to it. Mars is also glowing hot, with all of its atmosphere blown away by the ferocious solar wind from the Red Giant. Here is a screen shot (although I am still not satisfied with the Mars texture).



I am also going to change Jupiter's texture, since it will be closer to the Sun and surely will not look like it does now billions of years into the future, but I am looking for a reasonable banded cloud texture to use (from another add-on).

Anyway, stay tuned. I'll post the add-on on my website when it is done.

Frank

[Darkmiss]

This Project looks and sounds wonderfull
Great idea Frank

Anderea, and the rest of the Teachers out there are going to love this.

[billybob884]

This add-on is going to be so cool, can't wait to see it! Maybe you could enlist the help of Rass for textures, I'm sure he'd be eager to be part of an add-on like this!

[fsgregs]

Thanks for the encouragement, guys. Actually, I am wild-ass guessing about what Mars and Jupiter might look like when the Red Giant swells to its largest size. Will its heat be sufficient to bring Mar's surface above 2000 degrees C? If so, then we may get renewed vulcanism and lava flows. However, 5 billion years from now, the radioactive decay within Mars will have long subsided and the last I read, it would be volcanically dead. If so, then lava flows are not appropriate for the scene unless its surface gets very hot from the Red Giant. Rather, just some dark rocks covering the whole surface might be better (of course, Olympus mons and all of Mars' current features would have long eroded away).

Jupiter .... It's anyone's guess. I assume it would still have cloud bands but if we boosted its external heat, would the clouds be different colors?

I would also love to show Europa with its frozen ocean now melted. After all, if humanity somehow survives 5 billion more years (not a chance) and has somehow not figured out how to travel to other stars, Europa might have to serve as our new home.

If anyone has a good bumped texture of what they think Mars might look like in my screenshot above, and/or Jupiter and Europa, please let me know or e-mail it to me.

Also, the latest graphics I have from NASA artists depicts the surface of Neutron stars and pulsars as dark colored, almost black. If I recall, the pulsar available as a Celestia add-on from Ras is dark colored and I will use it in the Activity. However, I also need to depict a neutron star that has not become a pulsar yet, so I need a dark textured surface that will glow OK with emissive true, but will be dark brown or almost black. Sort of like the original pulsar texture without the bright beams. It should also be smooth. Neutron stars have enormous gravity and there is no such thing as hills or mountains on it. Some say it would be as smooth as a black bowling ball, with some occasional light peaking through. Does anyone has such a critter?

Thanks.

Frank

[granthutchison]

Frank:
The red giant isn't going to push Mars' temperature as high as 2000C - after all, the star's surface isn't much hotter than that, and it will fill considerably less than half the Martian sky.

And I'm puzzled: Why should a neutron star be brown or black? They're radiating at hundreds of thousands of kelvin.

Grant

[fsgregs]

Grant:

Thanks for the input on Mars. I sort of suspected that. What we need then is a good, well bumped rocky world that would be a high enough quality to represent Mars of the far, far future. Anyone have a good texture candidate?

I agree that a neutron star would be very hot initially and I felt it would not be much different in appearance from a white dwarf, since they are similiar. However, in a NOVA special I was watching on Gamma Ray Bursts, the graphic artist showed a neutron star as a dark, almost black rotating object. Ras's pulsar, which is also just a spinning neutron star, is also colored a darker brown, with just the light beams coming through. So, I'm just using what others have decided is what a neutron star would look like.

If it is a billiard ball smooth white object, then all I need is a whitish sphere texture. I guess I could even use "Astar.jpg", which is the default white star surface in Celestia, however, I kind of wanted to show the audience something different than what they had seen in an "A" star. Any suggestions for a neutron star texture? Perhaps I could simply call a texture sphere but leave the texture out. Celestia would then draw its white sphere without a texture at all. Would that do?

Also, what are your thoughts on Jupiter and Europa?

[selden]

Frank and Grant,

I suspect dark surfaces were chosen in order to try to accomodate the vast difference in brightness between the surface and what you see if the pulsar's beam of light hits you. A CRT can't show either of them realistically.

It's sort of like sunspots: in themselves they're incredibly bright. It's only when you compare them to the surrounding solar photosphere that they seem dark.

Added slightly later:
Also you might want to take into account the fact that pulsar beams are like flashlight beams: they're relatively dim from the sides if you compare them to what you see when you look down along the axis toward the source. How that sidewise brightness compares to the pulsar's surface brightness I dunno. It'd depend on what's in the path that would scatter light.

Does this help?

[Jeam Tag]

Frank,
cant help you, sorry, but i want to say:
that's a really very great project, hope to see it works! Thanks
Jeam

[granthutchison]

Frank:
The problem with neutron stars is that their surface is brighter than anything anyone has ever seen - several thousand times brighter than the Sun, hundreds of times brighter than the first few fractional seconds of an atomic bomb explosion. In the unlikely event you were close enough to see a visible disc, an unfiltered glance towards it would score a burnt track across your retina. And in a pulsar, the magnetic polar regions would be even brighter than that!
The colour of the light would be an intense blue-white, and I guess you might try for some pole-to-pole striations representing the intense magnetic field.

For the planets of a red-giant Sun, to some extent you can write your own script. They'll edge out to wider orbits as the Sun loses mass, but inner bodies like the Earth and Mars will also be braked by the outflowing gas - so the final positions and temperatures will vary with the evolutionary stage of the Sun, and are also a little unpredictable (see, for instance, http://www.nature.com/nsu/010510/010510-7.html).

Mars could end up with a temperature over 1000K, so might have a dull red glow to its nightside. But by that time, a lot of the Jovian system would be boiling dry, with temperatures over 500K - huge cometary tails streaming away from the icy satellites might be eye-catching.

Grant

[Cormoran]

Interesting idea; I'm really looking forward to seeing it (and flying round it).

Couple of minor points:

1/ Are you stopping with Jupiter? I suppose one general question would be how much of its current atmosphere would Jupiter lose at 500 Kelvin? Would we see a smaller body in its place? Would its cloud patterns be more chaotic due to the increase in energy infall?

2/ I believe Mars would look very different from how it does now even without the increase in temperature and zero tectonics, as Phobos would have fallen out of orbit by then (or was it Deimos).

3/ What would Titan be like?

4/ Would the rings of Saturn have evaporated a bit and darkened?

Just a few quick thoughts

Cormoran

[fsgregs]

OK, here is my version of a neutron star. It is a modified astar.jpg texture. I've colored it a blue-white as Grant has suggested with just a hint of surface texture.



What do you think?

Frank

[granthutchison]

Frank:
You've switched threads with this one, I think.
The black-body colour is actually pretty blue: for my Dell monitor, a million K has an RGB value of [0.476 0.595 1.000]. Whether you'd ever be able to detect the blueness in something so bright is another matter - I think searingly white from close up is as good as anything.
I guess you just haven't got around to setting a realistic radius (~10km)?

Grant

[granthutchison]

1/ Are you stopping with Jupiter? I suppose one general question would be how much of its current atmosphere would Jupiter lose at 500 Kelvin? Would we see a smaller body in its place?

The gas giants are massive enough not to lose atmosphere until they're very hot (there's a lot of published theory about this, since the discovery of "hot Jupiters" around other stars). We might expect Jupiter to increase in size a little as its atmosphere expanded.

2/ I believe Mars would look very different from how it does now even without the increase in temperature and zero tectonics, as Phobos would have fallen out of orbit by then

Phobos should form a faint Martian ring in about 50 million years' time, but that will long since have dissipated by the time the Sun is a red giant. Interestingly, though, Triton's orbit is also winding down over a longer time period - "billions of years" it says here, which might fit with the 5Gyr timescale we're thinking about. How about a dense ring around Neptune?

3/ What would Titan be like?

Good point. No idea, but it certainly isn't going to be an orange ball.

4/ Would the rings of Saturn have evaporated a bit and darkened?

Ring lifetimes are quoted in the hundreds of millions of years, so we could expect Saturn's present ring to have disappeared, 5 billion years from now.

Grant

[fsgregs]

OK, I changed the image to make it bluer while still keeping it white. See the graphic in my prior post above. It has now been updated to the new image. The blue atmosphere is the RBG setting that Grant suggested. I also dropped the radius to about 12 km (neutron stars range from 10 to 20 km, according to a reference I was using recently.

Is this OK?

Frank

[ElPelado]

Fisr of all: really good idea and good work till now. May we see picture of the Earth and Mars of the part iluminated by the sun?

If you pay attention to the bottom of the Neutron Star screen shot, you can see that the stripes are not there.
An other thing we dont see in the picture is the sun flare, i think its because you are using a planet with "emissive true". Cant you make it a star maybe??

The problem with neutron stars is that their surface is brighter than anything anyone has ever seen

So, should be a sun flare there?

About Phobos, i read that there are two posibilities: it wil brake and make a ring system around mars OR it will crash. you will have to decide...

In Europa maybe you can "put" inteligent life, and maybe also in Titan...

And about Saturn's rings... its true, they will dissapera. So it will be a very "boring-to-see-with-telescop" planet, right? It doents even have as many colors as Jupiter have... a shame...

[granthutchison]

You could "borrow" the flare from a Celestia neutron star, and lay your own texture on top using Calculus's trick of making a planet in a tiny orbit.
(Not sure about that visible atmosphere, though - a neutron star atmosphere is only millimetres thick!)
Here's an stc creating the neutron star:

Code: Select all

450000 "Neutron Star"
{
   RA 0
   Dec 0
   Distance 100
   SpectralType "Q"
   AbsMag 27
}

The absolute magnitude is very low here - this is because Celestia seems to assign a rather cool 10000K to neutron stars, so I've had to wind down the magnitude in order to get a 10km radius star at the end of the day. For a million K neutron star, abs mag is around 20.
And here's the ssc to lay whatever texture you want on top of it:

Code: Select all

"Neutron Star" "Neutron Star"
{
   Texture "bstar.jpg" # whatever you want
   Radius 12 # more than 10 in order to obscure star surface

   Emissive true

   EllipticalOrbit {
      Period          3e-8 # 1 second
      SemiMajorAxis   1e-12
   }
}

Grant

[fsgregs]

El Pelado:

OK, here is Earth just prior to being vaporized by the Red Giant. It is one of Don Edward's earlier textures of a volcanic moon. I think it is spectacular for this theme. Notice the red spec highlights from the Red sun. The thick haze is all that is left of the oceans.



I do not know how to add a texture to a star so that the flare appears around it. Usually, I would simply place a planet over an existing star so that it just covers the disk, but a neutron star is only 16 km in radius so it will not cover any of the stars in Celestia's database. Is there a way to create a fictional star in space with a texture and flare, and give it a neutron star texture? If so, please tell me how.

Thanks

Frank

[Don. Edwards]

Frank,
About Mars, since the temperature isn't going to be high enough to melt its surface it should look basically the same. It would go from a cold desert world to a hot desert world. But there is no real geologic activity on Mars anymore so its surface shouldn't be changing a great deal. The evidence is looking stronger that Mars may already be to cool in its interior to start any new volcanic activity even if it was hit by a fairly large asteroid like the one that made the Hellas basin.
I would consider taking a good Mars texture and bleeding off the color so it was more of a sandy color. The added heat from the swollen sun should cause changes in the soil and they should chemically change. The regolith would leach out its chemical and gas contents into the atmosphere. There is the possibility that if Mars was not terraformed it might develop a thick cloud cover of CO2 clouds. So in essence it would end up looking like Venus for a while. If you choose to go the route of Mars being terraformed by humans than you would have to take erosion into account. It all depends from witch direction you want to start from. You might want to keep some sense of the solar system. We no things are going to change but a few of the worlds in our system are not going to be changing to much unless we do the changing first.

As for Jupiter and its moons I do not know if the Sun will be putting out enough heat to melt any of the ice out there. Most of the Suns energy will go to the inferred part of the spectrum. I don’t know if there is a way to find out where the habitable zone around the sun at this time might be but if its near Jupiter than you can melt Europa into a water covered ball and make a whole lot of lakes and seas on Ganymede and Calisto.

If I wasn’t tied up with the 32k Realistic Earth this would be fun to play with.

[Guest]

Very nice work frank...Any textures I have out there your welcome too...I believe there could be a few that could be used for mars and jupiter...

And a few terrian ones for eurpoa...

[Rassilon]

Ahh I pulled a Fridger...

Tis my post above!