Earth: 3.8 Billion Years Ago

At a time when the first single-celled life forms appeared, the Sun was but a deep red fraction of its future self. The proto-moon (called Theia) had long since collided with the ancient proto-Earth, creating the Earth-Moon system as we now know it. Deadly asteroids, once everywhere, had thinned, leaving the Earth in a haunting, precarious peace.

The constellations of today’s stars would seem scattered, strange, and unknown.

While wrapped in the young Sun’s soft glowing red and infrareds, the Earth’s surface was not the Hellish nightmare commonly associated with the Hadean Era. Volcanoes – yes, earthquakes – most certainly, and water. Perhaps water enough to quench the planet, taming the flames of Hades; an ocean’s worth of water.

Therein stands a mystery! For such a small Sun, without its hot, powerful rays of sunshine, how could liquid water exist? How could the life-giving waves crash in thunderous cacaphony upon ragged, new born land?

The question has been posed. I await your answers.

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I’m afraid your a little in accurate in your knowledge of our solar system. By the time our moon had formed the sun would have been as bright as yellow as it is today, if not a little brighter.

Your render is very atmospheric but a little bland and simple for the effect you were looking for.

3.8 billlion years in the future and then your talking.

I have to agree with TheANIMAL, Thangalin, you should research the astronomy of your subject more carefully, especially the evolution of main-sequence stars like the sun. The kind of red star you depict is more typical of a main-sequence red dwarf, much lower mass than the sun. The sun will eventually cool to this level of emissions, but then it will be a giant star, its atmosphere engulfing earth, and far off the main sequence. More like 4 billion years into the future.

If your intent is to show a very early sun, a protostar, then the fairly dense volumetric atmosphere you depict is much too regular to represent an early solar nebula. And the planets would not even exist at this time, while the nebula was still condensing and only beginning to spin up to form the flattened disk of material out of which the planets would eventually condense. The sun’s visual wavelength emissions would be heavily masked by the dense dust of the nebula, which would heat up and re-emit mainly in the invisible infra-red. Associating visible red and infra-red isn’t necessarily a sound practice – many stars of very low visual magnitude are very bright IR emitters: many stars thought to be very early in their evolution show this characteristic.

Hi,

Regarding the expansion of the Sun:

  • Bahcall, J. N., Pinsonneault, M. H., and Basu, S. (2001). Solar models: current epoch and time dependences, neutrinos, and helioseismological properties. The Astrophysical Journal, 555:990*1012.
  • Couvidat, S., Turck-Chièze, S., and Kosovichev, A. G. (2003). Solar seismic models and the neutrino predictions. The Astrophysical Journal, 599(2):1434*1448.Regarding major Earth-related events (in billions of years ago):
  • 4.654 - Sun formed
  • 4.567 - Earth formed [1]
  • 4.533 - Theia collision [2]
  • 4.450 - Water evidence [3]
  • 4.404 - Zircon formed [4]
  • 4.400 - Crust evidence [5]
  • 3.800 - Life evidence [6]References:
  • Nature, 427:117120. DOI: 10.1038/nature02260. Boyet, M. and Carlson, R. W. (2005). 142 Nd evidence for early (>4.53 Ga) global differentiation of the silicate Earth. Science, 309(5734):576581.
  • Münker, C., Pfänder, J. A., Weyer, S., Büchl, A., Kleine, T., and Mezger, K. (2003). Evolution of planetary cores and the Earth-Moon system from Nb/Ta systematics. Science, 301(5629):84*87.
  • Drake, M. J. (2000). Accretion and primary differentiation of the Earth: a personal journey. Geochimica et Cosmochimica Acta, 64(14):2363*2369.
  • Valley, J. W., Lackey, J. S., Cavosie, A. J., Clechenko, C. C., Spicuzza, M. J., Basei, M. A. S., Bindeman, I. N., Ferreira, V. P., Sial, A. N., King, E. M., Peck, W. H., Sinha, A. K., and Wei, C. S. (2005). 4.4 billion years of crustal maturation: oxygen isotope ratios of magmatic zircon. Contributions to Mineralogy and Petrology, 150(6):561*580.
  • Harrison, T. M., Blichert-Toft, J., Müller, W., Albarede, F., Holden, P., and Mojzsis, S. J. (2005). Heterogeneous hadean hafnium: evidence of continental crust at 4.4 to 4.5 Ga. Science, 310(5756):1947*1950.
  • Manning, C. E., Mojzsis, S. J., and Harrison, T. M. (2006). Geology, age and origin of supracrustal rocks at Akilia, West Greenland. American Journal of Science, 306:303*366.Thus, 3.8 billion years ago, the Sun would have been approximately 70% of its current size. :slight_smile: See the attached image for details. The arrow going up represents the relative size of our Sun. The arrow to the right represents billions of years.

The question of whether or not the Sun would have emitted light in the low red spectrum in addition to the IR is a good one. When it first went nuclear, I’d imagine it emitted mostly IR. But, by the time our Sun was a billion years old, it was probably starting to set off a fairly decent glow. I think I have a reference that discusses our Sun’s spectrum around that time (3.8 Ga) and it mentioned both red and IR. I could be wrong; I’ll see if I can’t find the reference again.

[edit] Found this: http://www.maa.mhn.de/Scholar/star_evol.html During the protostar phase, it makes sense that there is a lot of dust and debris spreading around. This dust will block most of the light coming from the star, leaving the IR and microwave bands to pass. At this point, the star will have a reddish glow. As it grows in size, the colour changes. My presumption is that 3.8 billion years ago, the Sun was no longer a young protostar, but had not yet entered its “Main Sequence”. Thus the prevalance of dust would have long ago accretiated, burned, or otherwise vacated, allowing for the reddish light of the Sun to shine forth.

Thoughts?

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Thangalin - Very Good Picture & thanks for that research!

Don’t bother citing references that aren’t to the point of the critique. Relative size of the sun you depict isn’t a question, that’s impossible to determine from your image anyway. It’s the peak emissions being placed in the red end of the spectrum that doesn’t jibe with the apparent age of the system you’ve rendered. That and the uniformity of what could only be interpreted as the remnants of the solar nebula.

At the protostar stage, the general consensus, borne out by the study of prestellar globules like those found in Orion, is that all visual emissions would be blocked by the density of the still-condensing molecular cloud. Red is part of the visual spectrum. IR and microwave can penetrate such a cloud due to longer wavelength and also by the mechanism of absorption and re-emission. While the protostellar mass would likely be radiating chiefly in the red, its temp still not enough to initiate fusion, that radiation would be hidden deep in the cloud the star is born from. Your image shows it shining quite distinctly, with a well-defined disk, no evidence of the cloud other than a perfectly diffuse haze, which is inaccurate.

Once fusion has nearly begun and the star has entered the T Tauri phase, the veiling matter would still be present until radiation pressure had time to scour most of it from the system, leaving only the denser matter to continue coalescing to a planetary system. By that time, the star would have settled into its early main sequence emission, which for our sun peaks in the yellow to green, a black-body temp much closer to 5000K than the 2000K or so you depict.

Besides being far too homogeneous, the matter you depict enveloping the sun and planets shows no evidence of the flattening that would occur in a condensing solar nebula. There’s no indication of a nebular disk, nor of the clearing of an orbital track that would likely occur as planetary accretion continues. If you’re trying to portray a much later period, after the accretion has for the most part stopped, then the sun’s color is just that much more inaccurate, and the nebular haze would have been driven off completely by the solar wind.

who cares! nice render :yes:

Yet the astronomy discussion is interesting too.

anyone seeking to depict a scientific subject should care enough to get it accurate. Thangalin posted his image with reference to scientific considerations, and specifically asked for responses.

Would you think a human face with three eyes and no nose acceptable if it was a “nice render”? I doubt it. Unfamiliarity with a subject (astronomy) is a poor reason to accept misconceptions as fact just because they’re in a pretty package.

actually i think a render of a face with three eyes and no nose would kick ass…

No, seriously, while science can give us a good idea of when and why things happened, you’re still looking at a pretty huge margin of error. Even a 1% margin of error on these estimates is tens of millions of years. I think much of the water on the planet was more likely liquid due to the volcanic activity. You can still witness this in Yellowstone, where there is lots of liquid water all year round, There are areas where everything is frozen and it’s snowing, yet there are large pools of hot steaming water all over the place. The cooler parts of the planet would have been like that. I doubt the poles had any frozen liquid at that time, but then this is just educated guessing on my part. I’m probably wrong.

I still think a 3-eyed no-nosed face would look cool.

And to clarify, i have no idea the physics and timelines involved in star formation. The margin of error factor i’m talking about here is the assumption that water wasn’t in liquid form on the planet. I do think the image overall is nice, but taking some of the advice here would probably be a good idea if you were truely looking for accuracy (ie, adding some of the flattening dust effect mentioned, etc). As far as the image goes, i like it… it’s neat. :smiley:

ouch, now my brain hurts

As an example of a sideshow attraction it might have some grotesque appeal, but as an accurate depiction of a human face, it would fail miserably.

Regarding the time-frames involved, it’s true that they’re really immense and hard to grasp, but by reducing the numbers to fractions of a gigayear (as Thangalin did in his timeline post), they become a little more comprehensible.

Thangalin: “At a time when the first single-celled life forms appeared, the Sun was but a deep red fraction of its future self.” He pegs this at about 3.8Gya (billion years ago),

Using his timeline start at 4.654 Gya with the formation of the sun, and basing progress from there on the current theory for evolution of a one-solar-mass G-type main sequence star (that’s our Sun), I’ll add a few other points on the scale:

“4.654Gya – sun formed.” Let’s say that this is the point when the molecular cloud that was condensing to become our sun first began heating up enough to be called a “protostar,” not yet fusing hydrogen as the main source of energy (as it is today), but rather releasing the energy of gravitational contraction as heat. It would glow red because it’s surface temperature would be at about 2000 degrees Kelvin (2000K). It would also still be buried in the dense cloud of its birth, and invisible in the visual wavelengths. Its heat (IR) and microwave emissions could be detected though. Objects like this (called Bok globules) can be found embedded in the visible portions of giant hydrogen clouds – see the very cool Hubble telescope photos of these objects!

4.604Gya – start of “T Tauri phase” of the proto-Sun object. After at most about 50My (50 million years – a long time, but note that it’s only in the second decimal place of the number --short by astronomical standards), gravitational collapse is near its end because the heat & radiation pressure from the proto-Sun is enough to counter gravity’s effects, a condition called hydrostatic equilibrium. Studies show that this happens at around 4000K, giving the object a deep yellow hue. It would still be wreathed in dense tatters of the gas and dust from which it formed, which could also be glowing as well by now, perhaps producing the first visual appearance of a star-like object.

It’s also in this time period that a planetary system would be first be forming from irregularities in the rotating disk of material that the pre-solar nebula has now become – a circumstellar disk. This is thought to happen over a very short timescale compared to other processes, as little as 10My. During this time, the intense solar wind from the proto-Sun would also begin driving off most of the gases and lighter elements from the circumstellar disk, only that captured by what are now the gas giant planets being held back. Dust and heavier materials would continue to accrete into the rocky planets, asteroids, and comets.

By the end of this period, the star would likely be quite visible, and radiating at very close to its main-sequence surface temperature, which for our sun is about 5000K. It may also be significantly larger than our current sun, because it’s still contracting, though much more slowly.

4.504Gya – Beginning of the main-sequence period of the Sun. This marks the beginning of hydrogen fusion in the core of the Sun, ignited by temperatures raised to incredible levels by the further contraction of the solar matter. The size of the new star has stabilized to large degree, and its surface temperature as well. It has “burned off” the last remnants of it’s birth-cloud, only the planets and other rather insignificant debris remaining in evidence. The main-sequence stage of a star’s evolution can last for many billions of years, depending on its mass (high-mass stars burn out faster, low-mass stars last a long, long, long, long, long, long time).

Thangalin places his image in the timeframe of about 3.8Gya. That’s fully 700My after the sun has reached main-sequence by the above timeline. And even if my timescale is too short by fully 100%, it would still mean the sun was its bright, cheery, familiar self by no later than about 4.1Gya. Still 300My before Thangalin’s image.

The point of all this is not to bust chops but to show that for this type of image, presented as Thangalin did, in the context of illustrating a scientific concept, accuracy is extremely important. If he wants to present it as a work of imagination only, fine, he has license to do so as does every artist. But I see a great deal more potential for dramatic images in an accurate approach.

Personally I find the posted image rather bland and much too monochromatic, regardless of its scientific accuracy, or lack of it. The difference in cast-shadow density for the two spherical bodies seems much too great. They both could show more surface detail, having just survived millenia of near-constant bombardment by meteors, asteroids, and comets (and lions and tigers and bears, oh my! :wink: ) according to some current theories. Some indication of the division between land and ocean on the Earth would be more interesting. The nighttime sides of both bodies need not be portrayed as a featureless darkness, some shadow detail could be included to make them more interesting.

and iliketosayblah, sorry for the brain-bruise, but as they say, “no pain, no gain.”

eep, my brain is gonna blow!!! :slight_smile:

Oh, that’s nothin’.

The real mindblower is that the Universe started out with essentially three ingredients – mostly hydrogen, quite a bit less helium, and a smattering of lithium (I guess the Universe had to mellow out after the Big Bang :wink: ).

So where’d all the other stuff come from, the stuff that makes up you and me and basically everything we can see, hear, touch taste, smell, and otherwise bump into in one way or another from day to day?

It came from inside big stars. The very first, and maybe some of the second and later generations of stars. Really huge stars that eventually blew up and cast their ashes to the cosmic winds (aka, supernovas), those ashes being the heavier elements that eventually came together to form planets that eventually became hosts to the strange self-replicating chemicals we now call “life.” Joni Mitchell wasn’t being just poetic when she wrote “We are stardust…billion-year-old carbon.”

If that don’t wrinkle your gray matter, don’t know what will :slight_smile:

im afriad your still off cuz God made the solar system and it probly only looked like that (if at all) for about 1 day

Please don’t. Just don’t.

I love the discussion tho. it makes me want to buy a big thick astronomy book and start reading up on all this stuff. It’s funny, as a kid you can’t help but be fascinated with astronomy and stuff - every kid wants to be an astronaut at some point - but most just grow out of it. They are getting closer and closer to making aircraft that can ‘fly’ out to space and back, and it worries me that it might end up becoming a popular way to travel. I mean… When you fly now, you can spot the new guys cause they’re the only one’s staring out the window. I think it would be a shame if people became that jaded about space flight. That they wouldn’t even bother to look down at the planet while they were up there.

That was kindof random… sorry… Just wanted to have something more than just the first line in my reply i guess :stuck_out_tongue:

It’s happened before. I grew up through the Apollo years, watching moon shots from the beaches of eastern Florida, just south of the Cape. I found it incredibly dismaying that after Apollos 11 & 12, a great many people were looking on moon landings as “ho-hum, nothing new here.” People thought it was too expensive, with too little return on investment, and cut Apollo short. We’ve never gone back, never gone farther with manned missions, and now even the robot probes are getting the scant end of the accountant’s pens strokes. Fortunately, ground-based astronomy has still progressed, with the construction of amazingly ingenious new-generation telescopes.