What if Earth had a 12,000+ meter mountain range?

[gumboot]

Doesn't it give you pause that we have launched a telescope into space, but never built a single site at 6500m?

I think it was pointed out very early on in this thread that a 6,500m peak isn't high enough to get you clear of weather systems. As you say yourself; the weather is a major issue both for effectiveness of instruments and for basic operation.

At 12,000m you are above the majority of weather systems.

 

[Vic Vega]

But sure, I suspect it's doable.

Now?

As of right now in 2011, I don't think this is possible any time in the forseeable future.

 

[Travis]

Most of our present 6500+ meter peaks are in areas of troubled weather. There's a reason they have an observatory on Paranal and not on Aconcagua. You need a nice mixture of calm weather, clear skies, high elevation, stable rock and some plan of access. In a mountain range with many 12000m peaks there could, conceivably, be one or two that meet those criteria.

 

[Complexity]

Not necessarily. What effect would such a range have if it were oriented parallel to the prevailing jet stream?

The jet stream in the northern hemisphere (if I remember correctly from an Atmospheric Science class decades ago) usually has three to five lobes (looks very roughly like a sloppy sine wave laid around the hemisphere).

One of these lobes is often pinned down by the Rocky Mountains in the US and Canada - the jet stream finds it easier to go north of the mountain chain rather than over it.

My guess is that the jet stream would similarly avoid mountain ranges of the height that we are discussing.

 

[quarky]

We should build a 12km mt,. by god. And then see if we have the techno-wizardry to get a scope on top.

 

[rustypouch]

We should build a 12km mt,. by god. And then see if we have the techno-wizardry to get a scope on top.

That's just silly.

If we were building the mountain, we could pile the dirt underneath the telescope.

 

[gumboot]

That's just silly.

If we were building the mountain, we could pile the dirt underneath the telescope.

That wouldn't tell us if we could get a scope on top of a 12km mountain, however. It would only prove we could get a 12km mountain under a scope. Everyone knows we can do that!

 

[Finn McR]

A couple of comments:

a) Don't underestimate the cost of going into space. The James Webb Space Telescope is a 6.5-meter telescope, and is on track to cost $6.5B and will last for 10 years. It's just mind-bogglingly expensive. To compare, the next generation of ground telescopes are of 25-30m diameter, budgeted at $0.7-1.0B, and might easily last for 30 years. a 6.5m telescope on the ground would cost something like $80M IIRC.

...And JWST is designed to operate at a temperature of 30 K. As much as it costs to build mechanisms that work at that temperature, you buy a lot in terms of infrared astronomy.

 

[Travis]

I thought the JWST was supposed to cost more than ten billion now?

 

[Correa Neto]

Assuming mantle convection was faster in Hadean times, it's possible the equilibrium maximum height was greater, reaching well into the ionosphere. Maybe early mountain ranges acted as cooling fins for the planet. Gods know what the heat conductivity of the atmosphere was back then anyway.
...snip...

I've thought about this some time ago. Never managed to reach a conclusion; I guess I would need a better math/physics background to carry on some simulations and settle down the issue. Or maybe I never read the right papers. Probably a mix of both options- I would need the proper background to understand the papers if I read them...

Here's my 2cents- Higher heat flow would mean more volcanism, so probably higher odds of an Olympus Mouns-type mountain. However, higher geothermal grades also mean a more ductile crust and higher odds it would yeld due to the massive volcano's weight. Maybe the large shield volcanoes would crumble not unlike a tall pudding pile.

Aniway, my bets for creating a 12k mountain would be in the same process that built the Himalayas. Continent-continent colision, stacking buoyant material underneath buoyant material. If uplift due to crust thickness increase by thrust stacking is larger than the effects of gravitational collapse+erosion, the mountain chain grows. Don't know where this treshold would be. Continuing with the bet, I would go for something like the ~600My ago Pan African / Brasiliano orogenic collage which built Gondwana as a possible candidate to generate such a humongous mountain. Maybe Rodinia assemblage. Older collages such as NUNA/Hudsonland/Columbia and Kenorland (or the supercratons) would be at higher geothermal grades. Faster plate movements but more ductile lithosphere... Don't know.

All I know is that it would be a great place for a supervillain's lair.

 

[quarky]

Any guesses (educated) on the maximum height of man-made structures?
Any feasibility of hanging a scope on a balloon?

 

[roger]

One thing to bear in mind is that a 12km high peak would be above most weather systems, unlike a current world peaks.

Nothing about operating on a 12km mountain would be more extreme than operating at the South Pole except the lack of air pressure. We've had a manned base at the pole for over half a century.

If that's not extreme enough, the Russians operated Vostok Station for 37 years at the coldest site on earth.

The south pole has no humidity, no dust, and no wind (where they are planning to build an observatory). You don't need to be in a space suit to repair equipment there. You can fly a plane in and land beside the facility. You don't have 200mph winds driving ice, rocks, and dust into the equipment.

Mountain conditions are not a joke. We easily live on the South Pole. On 7000m peaks? Not so much. Half a century vs never.

 

[roger]

Most of our present 6500+ meter peaks are in areas of troubled weather. There's a reason they have an observatory on Paranal and not on Aconcagua. You need a nice mixture of calm weather, clear skies, high elevation, stable rock and some plan of access. In a mountain range with many 12000m peaks there could, conceivably, be one or two that meet those criteria.

Yes, but unfortunately mountain ranges have the habit of creating weather. That's why the Chile site is so popular - it's a huge plateau that not only gives you drive up access, but the weather is relatively benign. The HI site works well because it is essentially a lone peak there. If we ended up with a 12km volcano on an island I could see the possibilities - a chain like the Himalayas, not so much. I'm going with your OP - we had mountains this tall in the Americas, and they were a Himalayan type range.

For the telescopists - how much does wind in and of itself affect viewing? I would think it would be impossible to keep a telescope steady in 100mph winds. Does the fast moving air cause optical turbulence? Is there any conceivable way to keep a large scope in a totally enclosed dome? How long do you have to wait for a scope to cool down before using it. I ask because on the daytime on Everest you are often in a t-shirt, and sweating for the heat, and then the nights can swing to -50F. That's a wide temperature range unmatched in any current observing site.

For the pilots - is there anywhere on earth where you can fly at FL400, and not encounter head/tail winds in excess of 100kts? Despite claims of no weather at these altitudes, I seem to recall flying at high flight levels and the pilot announcing that they were descending/ascending to avoid wind or thundercloud formations.

 

[BenBurch]

Well, no telescope is stable in wind. This is why we build domes for fixed sites. And the dome opening does not need to be a slit; In severe conditions it is sometimes a beak-like projection from a mask that can slide up and down the dome's slit.

And almost all telescopes above a certain size will have adaptive optics where atmospheric disturbance and even earth tremors (if small) can be filtered out.

 

[roger]

At 12,000m you are above the majority of weather systems.

Evidence?

First, mountain ranges cause weather.

Secondly, the FAA seems concerned with high altitude weather. Chapter 13 of the FAA Aviation Weather. They discuss things like temperature in the tropopause (-50F to -70F), the existence of multiple jet streams, dense cirrus clouds, clear air turbulence, wind shears cause by mountainous topography, haze layers composed of ice crystals, static due to the cold air flowing over the canopy surface, icing due to tall cumulus systems, and sometimes detached cirrus clouds, thunderstorms, and hail in clear air. Those all sound like conditions we can expect on a 12km peak, and conditions that will adversely affect the seeing conditions and the condition of the equipment.

Sure, we are hypothesizing a mountain, so why not hypothesize near perfect conditions as well? I'm fairly sure we could come up with some combination of geography, geology, and location to end up with a site that is flat, dust free, reasonable wind free, etc. But, that isn't an interesting discussion. If everything is perfect, things would be, well, perfect. /eot.

Meanwhile, in the world that we actually inhabit, tall mountains are and have been the product of geologic forces creating huge chains that create their own weather systems, and that are deadly to continued human presence, and destructive to any equipment that we bring there. Realistically, it's a harsh environment, far harsher than the poles.

 

[roger]

And almost all telescopes above a certain size will have adaptive optics where atmospheric disturbance and even earth tremors (if small) can be filtered out.

Yes, but how successful are they, and what are the limits? After all, a major reason for suggesting the Dome C site is the rather unique lack of atmospheric disturbance there.

 

[Travis]

As far as the geology goes it is my understanding that the ancient North American mountains were formed by the collisions that created Rodina.

 

[BenBurch]

Yes, but how successful are they, and what are the limits? After all, a major reason for suggesting the Dome C site is the rather unique lack of atmospheric disturbance there.

They are amazingly effective. For Dome C, however, the nearly complete lack of water vapor plus the altitude of the site partially open the IR window, and the nearly complete lack of any clouds or dust or smoke in the air means that the stars can be observed even when the sun is above the horizon. (Scattering is the reason we cannot do that in most other places.)

 

[roger]

They are amazingly effective. For Dome C, however, the nearly complete lack of water vapor plus the altitude of the site partially open the IR window, and the nearly complete lack of any clouds or dust or smoke in the air means that the stars can be observed even when the sun is above the horizon. (Scattering is the reason we cannot do that in most other places.)

Well, I'm trying to learn, but this is what Wikipedia says about it:

Starting in the 1990s, many telescopes have begun to develop adaptive optics systems that partially solve the seeing problem, but none of the systems so far built or designed completely removes the atmosphere effect, and observations are usually limited to a small region of the sky surrounding relatively bright stars.

source

The Mount Wilson site claims they get as good performance as HST, but that is because the weather is very stable there, with very light winds.

My question relates to performance in 100mph+ winds.

I'd imagine there would be a tradeoff - higher altitude = less atmosphere, thus better viewing, but high winds, wind shear due to topography, etc., would degrade viewing. From what I've read the relationship of the jet stream to the Himalayas is not fully understood yet, but it seems to be symbiotic - the high mountains cause abrupt temperature gradients, along with blocking moisture coming from the oceans, resulting in monsoons on one side, deserts on the other, and the creation of the jet stream that the tall mountains sit in. For example, K2 at the time of this posting is seeing winds in the 70+ mph range, and will be at 85+ by next week (source).

Temperatures are running at -20 to -30, though that will get worse. The Keck site says a major problem is chilling the dome during the day to minimize deformation during the evening. (http://www.keckobservatory.org/about/telescopes/). At 12K air temps average in the -50 to -70 range. It's not clear to me how you would maintain temperature equilibrium. I know that at Dome C they took the opposite approach - the equipment could not work at the temperatures encountered there, so they actually heated to the dome to -10C or so, and buried the computers and such to isolate them from the worst temperatures. (source) On that page they emphasize the advantage that having little wind provides to that location.

None of this is to say it is an impossible task. But putting an observatory in a place where humans need space suits, where encountering the jet steam is likely (the ESO closes the dome when winds are at 45, and it can't point into the wind at lower speeds), where rapid buildup of rime and solid ice is likely, at temperatures that computers do not work, with no easy way to provide infrastructure (travel, power) just isn't an easy task, and the result will be a location with limited viewing time due to the atmospherics and weather. To my mind no one has made a convincing case that this is a realistic use of resources.

 

[ben m]

Well, I'm trying to learn, but this is what Wikipedia says about it:source

My question relates to performance in 100mph+ winds.

I'd imagine there would be a tradeoff - higher altitude = less atmosphere, thus better viewing, but high winds, wind shear due to topography, etc., would degrade viewing.

Remember that SOFIA is able to work despite being in a jet airplane traveling at 400mph. That's turbulence galore, but they can handle it.

The problem with turbulence is that it can degrade seeing. This is only a problem if you're seeing-limited to begin with---which only occurs with optical and NIR telescopes to begin with. If you're going to ultrahigh altitude, though, you're doing it to push the far IR---that's where ground-based telescopes get killed with water vapor and sky brightness---and far-IR telescopes are more likely to be diffraction limited.

Obviously there's no way to resolve the "is Mount Insanity better than Mauna Kea" question without all the details in front of you. Obviously Mount Insanity is more a more expensive site, for the same scope, than any climbable mountain. The question is whether it's more expensive for the same *astronomy*.

I think it's persuasive that a scope atop Mount Insanity is cheaper than the same scope *in space*. I outlined a brute-force, no-new-technology, mine-your-way-to-the-top approach that sounds like $500M for mining, giving you a shaft big enough to haul a 2.5m scope up fully assembled. Compared to a space telescope budget (Spitzer, for example, at 0.8m and $800m) that's an easy win.

I think you're going out of your way to imagine the worst possible weather. 200mph wind, rime ice, clouds---sure, sometimes. Those are details that *depending on the reality* would go into the detailed decision-making. But they're not so obviously showstoppers that we can't have fun imagining a more optimistic version of things.