Difference between revisions of "1752: Interplanetary Experience"

Explain xkcd: It's 'cause you're dumb.
Jump to: navigation, search
m (Explanation)
(Explanation)
Line 17: Line 17:
 
Basically nowhere in the {{w|solar system}} is even close to survivable (except Earth and to be realistic there is also just a few regions on Earth that offer hope for long term survival). There is no planet or moon with a breathable atmosphere, or where the temperature stays within the human -tolerable range of roughly −20°C to 40°C (−5°F to 105°F, 250-310 K). The only place humans have so far ventured off-world is the Moon, and only during lunar morning while wearing thick pressurized spacesuits. Some celestial bodies, like {{w|Venus}} and {{w|Jupiter}}, may ''never'' be visitable by humans without either huge advances in {{w|material science}} or full-scale {{w|terraforming}} and some places, like the centers of any planet being it the {{w|gas giants}} or even Earth it self, will probably never be visited even by robots. (The title text suggest what happens when falling towards the center of a gas giant).
 
Basically nowhere in the {{w|solar system}} is even close to survivable (except Earth and to be realistic there is also just a few regions on Earth that offer hope for long term survival). There is no planet or moon with a breathable atmosphere, or where the temperature stays within the human -tolerable range of roughly −20°C to 40°C (−5°F to 105°F, 250-310 K). The only place humans have so far ventured off-world is the Moon, and only during lunar morning while wearing thick pressurized spacesuits. Some celestial bodies, like {{w|Venus}} and {{w|Jupiter}}, may ''never'' be visitable by humans without either huge advances in {{w|material science}} or full-scale {{w|terraforming}} and some places, like the centers of any planet being it the {{w|gas giants}} or even Earth it self, will probably never be visited even by robots. (The title text suggest what happens when falling towards the center of a gas giant).
  
Below is a [[#Table of celestial bodies|table]] going through the seven suggested places on Earth. Due to the low pressure and low  temperature on the top of {{w|Mount Everest}} is mentioned no less than three times but using different time of day. Likewise both the Moon and Mercury are mentioned twice, as there are a huge difference wether on the sunlit face of these two or in the shadow on their night side. On the other end of the temperature scale are mentioning of {{w|lava}} and a {{w|blast furnace}} and also high pressure environments are suggested to simulate other planets.
+
Below is a [[#Table of celestial bodies|table]] going through the seven suggested places on Earth. Due to the low pressure and low  temperature on the top of {{w|Mount Everest}} is mentioned no less than three times but using different time of day. Likewise both the Moon and Mercury are mentioned twice, as there is a huge difference in environmental conditions between the sunlit faces of these two and their night sides. On the other end of the temperature scale are mentions of {{w|lava}} and a {{w|blast furnace}}; also high pressure environments are suggested to simulate other planets.
  
 
The title text is just a continuation of the last entry about falling down through the atmosphere of a gas giant, and it is also explained in the table below. This was also explored in the [[what if?]] {{what if|138|Jupiter Submarine}}.
 
The title text is just a continuation of the last entry about falling down through the atmosphere of a gas giant, and it is also explained in the table below. This was also explored in the [[what if?]] {{what if|138|Jupiter Submarine}}.

Revision as of 13:06, 28 October 2016

Interplanetary Experience
But instead of hitting the ocean, you should land in an overheating hot tub on a sinking cruise ship, sending it crashing through the floor into the burning engine room as the ship goes under.
Title text: But instead of hitting the ocean, you should land in an overheating hot tub on a sinking cruise ship, sending it crashing through the floor into the burning engine room as the ship goes under.

Explanation

Ambox notice.png This explanation may be incomplete or incorrect: More details?
If you can address this issue, please edit the page! Thanks.

This comic list all the other seven planets (than Earth) as well as the dwarf planet Pluto and two moons; the Earth's Moon and Titan the largest moon of Saturn. And then it asks what places on Earth people could go to, to try and have a real Interplanetary Experience, as if they where explorers on these planets. It turns out that none of these ten other worlds are very nice to visit...

This is a muck-up on organizations that in preparation for future planetary exploration organize half-realistic experiments in human behavior on other planets, trying to emulate or mock-up - often on low budget - the conditions in which future explorers are to live and work. For this purpose, they build mock-up bases, habitats etc. in places that look like other planets or have the environmental conditions somewhat similar to other celestial bodies' surfaces. They seek out desolate places like deserts or polar regions for this purpose.

In this comic Randall tries to identify places on Earth that actually have environmental conditions as close to these other worlds' as can be possible on the surface of the Earth. Some of the places suggested by Randall are borderline-survivable for a human, but most will kill you extremely quickly without a lot of high-tech gear - whether through severe hypothermia, conflagration, crushing, or whiplash from violent winds.

Basically nowhere in the solar system is even close to survivable (except Earth and to be realistic there is also just a few regions on Earth that offer hope for long term survival). There is no planet or moon with a breathable atmosphere, or where the temperature stays within the human -tolerable range of roughly −20°C to 40°C (−5°F to 105°F, 250-310 K). The only place humans have so far ventured off-world is the Moon, and only during lunar morning while wearing thick pressurized spacesuits. Some celestial bodies, like Venus and Jupiter, may never be visitable by humans without either huge advances in material science or full-scale terraforming and some places, like the centers of any planet being it the gas giants or even Earth it self, will probably never be visited even by robots. (The title text suggest what happens when falling towards the center of a gas giant).

Below is a table going through the seven suggested places on Earth. Due to the low pressure and low temperature on the top of Mount Everest is mentioned no less than three times but using different time of day. Likewise both the Moon and Mercury are mentioned twice, as there is a huge difference in environmental conditions between the sunlit faces of these two and their night sides. On the other end of the temperature scale are mentions of lava and a blast furnace; also high pressure environments are suggested to simulate other planets.

The title text is just a continuation of the last entry about falling down through the atmosphere of a gas giant, and it is also explained in the table below. This was also explored in the what if? Jupiter Submarine.

Table of celestial bodies

Celestial bodies Place on Earth Explanation
PlutoMoon (night)
Mercury (night)
Mt. Everest at night The dwarf planet Pluto is a small icy rock so far away from the Sun that it practically makes no difference if it is day or night, the Sun is just the brightest star in the sky of Pluto's "day" side . But for both the Earth's Moon and Mercury (the innermost and smallest planet of the solar system it makes a huge difference, which is why there is both a day and a night experience mentioned for these two celestial bodies (see below). Although they are very much closer to the Sun than Pluto this makes no difference during their night time (when they face away from Sun). They are both relatively small, rocky bodies with practically no atmosphere and relatively slow rotation. Therefore their surfaces not illuminated by the Sun will cool down to very low temperatures (around -170 °C, -290 °F, 100 K), making their nighttime hemispheres desolate, dark and cold places. Randall proposes the summit of Mount Everest (the tallest mountain on Earth) as the place that will emulate the conditions most closely. It is a rocky, desolate and cold place. Even though it is not the coldest place on Earth, it is the highest point on land, therefore it has the lowest atmospheric pressure. It cannot be compared to the near-zero pressure and 100 Kelvins conditions on the aforementioned bodies, but it is as close as you can get on Earth. The top of Mt. Everest has an air pressure just 1/3 of what it is at sea level, and the oxygen levels are so low that they are barely survivable although a few people have reached the top without oxygen tanks, but others have died after losing their supply, making it as close as you can get on Earth to the near-vacuum found on these worlds.
Moon (day) Mt. Everest at noon under a tanning lamp As explained above, Mount Everest is as good emulation of the Moon surface at night as you can get. During the Moon's day, its surface gets about as much Sun's radiation as Earth at noon, because both bodies' distance from the Sun is almost the same. The Earth's atmosphere, however, stops most of the Sun's ultraviolet radiation. A tanning lamp is a device emitting mostly ultraviolet radiation for the purpose of artificial tanning; here it is used to augment the filtered Sun's radiation in an attempt to emulate Moon's daytime conditions better. Since the Moon does not have any atmosphere it is hard to discuss the temperature experienced on the Moon, but still the surface of the Moon reaches temperatures above waters boiling point (100°C or 212 °F) during the day with an average daytime temperature of the Moon at 107°C (224.6 °F). This effect will not be very well emulated on the tip of Mount Everest (or even in the hottest (non volcanic) places on Earth's surface that reaches 53.9°C (129°F) - see the what if? Flood Death Valley).
Mercury (day) A lava flow at a volcano at noon Mercury's surface never quite reaches lava temperatures (if it did, it would be molten), but it gets close. At noon, Mercury's equator reaches 420°C (800°F, 700 K). Lava is a liquid usually at temperatures from 700 to 1,200 °C (1,292 to 2,192 °F, 970 K to 1470 K) but depending on what type of rock it's formed from, lava can erupt at temperatures as low as 500°C-600°C (930°F-1100°F, 770-870 K). Standing on a volcano on a partially solidified lava flow (which, it goes without saying, is incredibly dangerous) would expose you to similar temperatures.
Near the poles, Mercury's surface temperature is always very low as the axial tilt is almost zero meaning that the poles do not get much direct sunlight and their temperature is constantly below −93 °C (−136 °F, 180 K).
Venus A heat-shrink wetsuit in a blast furnace The average surface temperature on Venus is around 470°C (870°F, 740 K) (enough to melt lead at 327 °C (620°F, 600 K), which is the usual comparison), and the pressure is 92 bar (by comparison, pressure on earth is only about 1 bar). A blast furnace is a bit too hot - the blast itself is 900 °C to 1300 °C (1600 °F to 2300 °F, 1170 K to 1570 K), and they can reach 2000 °C - but either temperature is enough to kill you in seconds. As the blast furnace would emulate Venus temperature but not pressure, Randall proposes a daring volunteer shall wear a hypothetical heat-shrink wetsuit. A wetsuit is an elastic garment worn mostly over the whole body by swimmers, divers etc. Heat-shrink tubing is a tube made of a material that shrinks when heated, used to provide extra insulation and mechanical or environmental protection in electrical and electronics work - you put a length of tubing over your wire, connector, or a joint and heat it with a hot air gun, making it shrink and crimp over your device. A hypothetical heat-shrink wetsuit worn while sitting in a blast furnace supposedly would shrink rapidly in the extreme temperature, extorting great pressure on your body, thus emulating Venus surface atmospheric pressure. In other words, do not go to Venus!
Mars Mt. Everest at sunset Again use Mount Everest's thin atmosphere and very cold temperatures to emulate the planet, but Mars's dusty, greenhouse-gas-containing atmosphere means it's not as cold as Mercury at night, nor as hot as the Moon during the day. Also the sun is much longer from Mars than from the Earth/Moon system, but much much closer than Pluto, so it should be colder than on the day side of the Moon. But the Sun still looks like a sun rather than a star from Mars, unlike on Pluto. The sunset will also make the sky reddish-purple, similar to the way the Martian sky often looks.
Titan Waist-deep in an outgassing Siberian swamp Titan, the largest of Saturn moons (and one of the largest moons in the solar system) is one of the promising worlds for life - given that its surface temperature is −180°C (−290°F, 95 K), that says a lot about how inhospitable the rest of the solar system is. The chemistry of the planet is interesting - there are lots of nitrogen compounds and hydrocarbons, and the atmosphere is mostly nitrogen and methane, and it has been confirmed that are methane lakes and it thus follows that there is likley to also be precipitation of methane "snow", much as water forms lakes and falls down as sleet on Earth. Similar compounds are produced by rotting material in swamps, hence the comparison to a cold Siberian swamp. Due to the global warming large area of the tundra in Siberia that used to be permanently locked in permafrost are now heating up enough to release these gases. It might thus be possible to end up waist deep in one of these "heated" swamp areas due to the resulting outgassing. Sadly for the global temperature this outgassing just increases the release of greenhouse gasses, making the global warming increase even faster. This may very well be the reason Randall chooses to mention it here, as another call back to recurring theme of Climate change and to the recent comic 1732: Earth Temperature Timeline. One key difference though is that on Earth, swamps are mostly water. On Titan, they're liquid methane. Siberia also has some of the most extreme temperature differences on Earth, while Titan is just consistently cold. The coldest place in Siberia is the Pole of Cold, the coldest point in the Northern hemisphere having reached −71.2 °C (−96.2 °F, 202 K). Not quite Titan levels of cold, but certainly deadly enough. But in such cold places there would be no outgassing, so on Earth it is not possible to have both the cold and the outgassing.
Jupiter-Neptune Jumping from a high-altitude balloon over an Antarctic Ocean winter storm Note that it is Jupiter to Neptune thus including also Saturn and Uranus. They are under one called gas giants for a reason. All the planets are very cold and have stormy weather (Uranus is the least active, and Neptune is the most active) and a very dramatic temperature and pressure gradient. On the edge of the atmosphere, conditions aren't much different to space, but as you fall in, the temperature and pressure rapidly increases past freezing point (allowing clouds of ice and water). This last entry's description of the place on Earth continues in the title text, see below.
Jupiter-Neptune (continued from above in title text) But instead of hitting the ocean, you should land in an overheating hot tub on a sinking cruise ship, sending it crashing through the floor into the burning engine room as the ship goes under. The title text continues the last entry in the main comic. So this explanation is also a direct continuation of the above entry. The very dramatic temperature and pressure gradients mentioned does not stop when the atmosphere temperature and pressure increases past freezing point. But soon the temperature reaches past boiling point, and up to thousands of degrees and unimaginable high pressures increasing further until the central core. The cores of Neptune and Uranus most likely consist of rock (superheated silicates, iron and nickel) or in the case of Saturn and Jupiter of liquid metallic hydrogen, where the extreme high-pressure and temperature causes hydrogen to behave like a metal. This is a theory as it is not something our technology is currently able to reproduce. The suggested simulation of this environment is to fall into a super hot bath tub that falls into the burning engine room of a ship that is sinking, and thus is about be become crushed by the water pressure of the deep ocean. This is the closest imaginable representation of the pressure and temperature conditions of the inner parts of the gas giants that can be imagined on Earth, but of course the cores of these planets are far, far more inhospitable than that as mentioned above. Descending into Jupiter was also explored in the what if? Jupiter Submarine.

Transcript

[Caption above the panel:]
Where to go on Earth to get the Interplanetary Explorer Experience
[A chart with seven rows with celestial bodies on the left side of seven lines and a description on the right side. The first entry has three celestial bodies in two rows, the rest are in one row, although the last entry encompasses a list of planets. Four times the day/night side of the celestial bodies is mentioned in brackets.]
Pluto, Moon (night) Mt. Everest at night
Mercury (night)
Moon (day) Mt. Everest at noon under a tanning lamp
Mercury (day) A lava flow on a volcano at noon
Venus A heat-shrink wetsuit in a blast furnace
Mars Mt. Everest at sunset
Titan Waist-deep in an outgassing Siberian swamp
Jupiter-Neptune Jumping from a high-altitude balloon over an Antarctic Ocean winter storm


comment.png add a comment! ⋅ comment.png add a topic (use sparingly)! ⋅ Icons-mini-action refresh blue.gif refresh comments!

Discussion

The Mars at sunset might also be reference to "alpenglow." A simple Google of "alpenglow" should suffice as explanation 172.68.54.126 (talk) (please sign your comments with ~~~~)


The explanation starts out saying that this list includes all the other planets in our system as well as a couple moons, however uranus and saturn are clearly left off the list. 108.162.238.37 15:16, 28 October 2016 (UTC)

Retracted, I did not understand the hypen in the last line. 172.68.78.125 16:18, 28 October 2016 (UTC)

Actually, the upper atmosphere of Venus has Earthlike temperature and Earthlike pressure - it is, indeed, pretty much the only planetary location in the Solar System safer enough than deep space to be worth the gravity well (you need a balloon to keep you aloft, oxygenated air, and protection from the sulfuric acid, but Earth air is a lifting gas on Venus so the first two solve each other). So "do not go to Venus" and "nowhere is even close to survivable except Earth" aren't quite true. The surface of Venus is absurdly inhospitable even to machines, but one shouldn't write off the whole planet so quickly. Magic9mushroom (talk) 04:02, 29 October 2016 (UTC)

I definitely think the part about Venus atmosphere is not only hot and dense, but also highly corrosive is worth mentioning. Sulfuric acid, phosphoric acid ... -- Hkmaly (talk) 17:53, 29 October 2016 (UTC)


This could also be a reference to the short movie Wanderers by Erik Wernquist and narrated by Carl Sagan. In the movie we can see imaginary scenes where humans are trekking the solar system for personal exploration. /LordSillion - https://vimeo.com/108650530 162.158.134.178 04:21, 11 January 2017 (UTC)

Someone who is good at this kind of things should also change the transcript to get rid of the table. --Lupo (talk) 12:16, 18 January 2019 (UTC)