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Questions regarding an envelope of gasses surrounding a celestial body held in place by the body's gravity.

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3answers
3k views

Why didn’t the Spacecraft used for the Apollo 11 mission melt in the Earth’s Atmosphere?

My brother has recently been converted to a Flat Earther and is convinced that something that proves his theory is the moon landings being faked by NASA. I have managed to counter argue the majority ...
19
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1answer
3k views

Has the Earth's red atmosphere rim ever been photographed?

In the Wikipedia article on Lunar eclipse there's given an image of how the Earth would look from the eclipsed Moon: This is obviously a schematic drawing. So I wonder, has the Earth ever been ...
3
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1answer
67 views

What effects does atmosphere have on solar panels?

For the purpose of this question I do not want to focus simply on the fact that there will be less "night time" for the panels while in orbit/outside the atmosphere of a planet. What I'd like to ...
4
votes
4answers
298 views

What is the most economical way to vaporize the CO₂ deposit near the south pole of Mars?

In April 2011 NASA announced that the Mars Reconnaissance Orbiter had found a large, buried deposit of frozen carbon dioxide at the planet's south pole. It has a volume of about 12,000 cubic ...
5
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1answer
116 views

GMAT atmosphere

I am using GMAT to propagate satellite motion with Jacchia-Roberts atmosphere model. Here is a formula used from this model which is then used to estimate the variation in drag on a spacecraft due to ...
2
votes
2answers
99 views

What is the deepest part of Mars?

Is there any particular deep areas of Mars in which a person could survive with only an oxygen supply without a pressurized suit? Or how deep would one have to be in Mars not to need a pressurized ...
16
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3answers
1k views

How can an *increase* in atmospheric temperature cause an *increase* in the atmospheric mass density?

We often hear that heating Earth's atmosphere from solar activity or CMEs increases the mass density of the atmosphere at a given altitude, causing orbiting spacecraft to lose altitude faster from ...
2
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0answers
66 views

How does Mars have a Bow Shock and proton aurora? What is a hydrogen corona?

I just saw the NASA video Mars Proton Aurora below and I'm confused. Without a planetary magnetic field, what force produces a bow shock in the solar wind at Mars, thereby producing a "proton aurora"?...
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0answers
106 views

Could a shuttle be built for Mars?

Mars does have an atmosphere, but is there enough atmosphere to glide, shed speed and land if there was a runway? What would this require from the shuttle, in terms of aerodynamics?
57
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4answers
10k views

Could we breathe an atmosphere that is not nitrogen based?

As I understand it, the important part of Earth's atmosphere that we breathe is the oxygen. However, Earth's air is only about 21% oxygen with the rest made up of about 78% nitrogen and 1% other gases,...
16
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4answers
3k views

Are there any known atmospheres that would support traditional combustion engines?

If we landed a traditional automobile on the moon, the combustion engine would lack oxygen, and, for obvious reasons, would not function. I'm wondering if a planet terrestrial body exists where we ...
2
votes
1answer
96 views

Where are we in the current effort to make mars habitable? [closed]

I feel like this should be a massive effort put forth by all countries. As a civilization, our population is growing at a break-neck rate. Not only would it be a fail-safe should something happen to ...
1
vote
1answer
67 views

What is the science behind the variation of Mars' effective sky temperature with latitude and longitude? Why the “hot spot”?

After reading this interesting answer to the question How cold is the Martian sky at night? Or the day for that matter? I found that Mars Global Reference Atmospheric Model 2001 Version (Mars-GRAM ...
9
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2answers
291 views

Is Mars' gravity strong enough to hold a human-breathable atmosphere?

If we ever try to make Mars outdoors habitable, won't the air just keep flying off into the outer space because of low gravity?
4
votes
1answer
104 views

Is really almost all the water in the atmosphere of Venus above the clouds?

In this question about the amount of sulfuric acid in the atmosphere of Venus it is calculated that the amount of water in it's atmosphere is $9.6 \times 10^{15} \text{ kg }$ H$_2$O. In one of the ...
6
votes
1answer
97 views

How much does pressure on Mars change with weather?

A great answer about the Mars atmosphere and water triple point shows there is a region on Mars where clean liquid water slightly above 0°C can exist on the surface. I still wonder, though, how ...
8
votes
2answers
482 views

Why not bring life to the atmosphere of Venus along with the next exploring mission?

Why not bring cyanobacteria and fertilizer to the atmosphere of Venus to improve conditions for life there by producing oxygen ? Planetary protection could be a reason. According to Wikipedia: ...
14
votes
4answers
4k views

Could we see the surface of Venus after the explosion of a H-bomb in its atmosphere?

The dense atmosphere of Venus is mainly composed of carbon dioxide and nitrogen, with clouds made of sulfuric acid droplets, which make optical observation of the surface impossible. As can be seen ...
2
votes
3answers
179 views

Are the mountains of Venus of any help for us to explore the surface?

The circular orbit and small axial tilt results in no seasons, coupled with the well-known strong greenhouse that makes nights just as hot as days. As pressure gets lower by height, so does ...
2
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1answer
37 views

Concentration of gases in an atmosphere

this question made me think what type of technique is used to get concentration of gases on planets? One can get the composition using spectrometry but is there anyway to tell concentration of each ...
2
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0answers
40 views

Does Juno's UVS have any chance to spot Europa plumes?

JIRAM has recently been proven to be useful to monitor the volcanic activity on Io, from a considerable distance. Europa Clipper will have an ultraviolet spectrograph which be pretty much a copy of ...
2
votes
1answer
118 views

What are the ranges a human can survive AND breathe in?

I am writing a space sci-fi short story series, and I am trying to figure out what the range in pressure a human can survive AND breathe. I am trying to find the lowest, safest air pressure a human ...
1
vote
0answers
23 views

Looking for atmospheric density models of various planets and moons

Looking for atmospheric density models of various planets and moons, any sort of data/resources/database of this information would be extremely useful as I am working on recreating these models for ...
0
votes
1answer
94 views

What is the procedure when a spacesuit gets a tear in it? [duplicate]

What do you do if you are in space and you get a rip in your spacesuit other than getting right with God? What if you cannot get back to base in time?
1
vote
1answer
144 views

Can air pressure be accumulated this way for a biodome or spacesuit?

Using plastic or rubber or something similar and transparent be inflated with each layer having a increasing pressure lessening the strain on the containing material? When one or two layers fails the ...
2
votes
0answers
58 views

How does methane waste produced by the ISS interact with our Atmosphere?

The ISS uses a Sabatier reactor to recover oxygen from carbon dioxide. This has an output product of methane. I would imagine that most methane that enters our atmosphere at ground level only reaches ...
2
votes
0answers
43 views

Building a Drag model for rocket optimization

I need to build a drag model for my rocket optimization program and I stumbled upon by the following formula: $CD = CD_c(M)$, $K_n < K_{nc}$, $CD = CD_{fm}$, $K_n > K_{nf}$, $CD = CD_c +(CD_{...
1
vote
1answer
128 views

Space Station in atmosphere with continuous reboosting to preserve orbit

I recently watched the series Altered Carbon. In that series, they showed a floating space station called "Head in the Clouds". There is a blue sky here, even clouds. This would imply a height of &...
0
votes
2answers
134 views

How much soil can be supported by an inflatable habitat on Mars?

What weight of Martian soil can be supported by the top of an inflatable habitat pressurized at Earth's atmosphere? While habitat's shape is a huge factor, this has 20 meter modules, semi-cylindrical ...
10
votes
2answers
527 views

Will uncovering the ice deposit in Utopia Planitia improve the climate on Mars?

In 2016 a large ice deposit has been found within the Utopia Planitia region on Mars by the SHARAD instrument on board of the Mars Reconnaissance Orbiter. The thickness of the deposit ranges from ...
5
votes
1answer
258 views

Launching sounding rockets from the magnetic equator (ISRO's Thumba)

The Thumba Equatorial Rocket Launching Station is operated by ISRO for launching sounding rockets because magnetic equator passes through it. Equator gives additional velocity, But what advantage ...
4
votes
0answers
67 views

Could metal sulfates stay in the sulfuric acid layer of Venus?

For cyanobacteria metal ions like K+, Mg+ and other essential nutrients like phosphorus are vital for growing and to expand. So they could only thrive in the clouds of Venus if at least metal ions ...
5
votes
0answers
154 views

Why not simulate certain regions of the atmosphere of Venus?

Many people would like to know if any form of life could survive anywhere in the atmosphere of Venus. Researchers have simulated conditions on Mars and found that after a month some cyanobacteria ...
4
votes
0answers
75 views

What is the typical size of the sulfuric acid droplets in the atmosphere of Venus?

According to Wikipedia: Venusian clouds are thick and are composed mainly (75-96%) of sulfuric acid droplets. These clouds obscure the surface of Venus from optical imaging, and reflect about 75% ...
3
votes
2answers
244 views

Does “What happens beyond Kármán, stay beyond Kármán”?

The title refers to the promotional slogan "What happens in Vegas, stays in Vegas." The question How much CO2 would city-to-city rocket flight produce compared to airliners? seems to be focused on ...
7
votes
1answer
282 views

Can there be an atmosphere in a cave on an atmosphere-less planet?

I am making an exoplanet for a game and was wondering whether a planet without an atmosphere (or at least with a very weak atmosphere) could support caves that do have an atmosphere, or whether the ...
2
votes
0answers
68 views

Range of atmospheric pressure and composition for plant survival?

I am currently working on a college senior design team that is looking at developing a small modular habitat that could sustain plant growth. These small modules would not include humans, so we only ...
6
votes
1answer
247 views

Has an astronaut ever seen pixies, ELVEs, sprites or blue jets (without a camera)?

The NASA Science video ScienceCasts: A Display of Lights Above the Storm shows several examples of Transient Luminous Events (TLEs) (Upper Atmospheric Lightning) being filmed by high-sensitivity ...
9
votes
2answers
248 views

Would a mars base need to expel excess heat?

I've read that on Mars you lose 30% of your heat through convection and 70% through black body radiation. (The much lower amount from convection due to the tenous atmosphere vs. Earth.) http://www....
5
votes
1answer
162 views

Apparent temperature Mars

Apparent temperature is the temperature equivalent perceived by humans, caused by the combined effects of air temperature, relative humidity and wind speed. There are several ways of measuring it, ...
10
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2answers
222 views

Does atmospheric entry shake the craft?

Does atmospheric entry shake the craft or does the process force the craft to fly in a straight line without causing vibrations? Sci-fi movies and all have the craft shake very slightly. It would ...
3
votes
3answers
243 views

Could a terrestrial planet with a hydrogen atmosphere be habitable?

Many exoplanets, even small ones, have densities so low that it indicates that they have hydrogen atmospheres. Is a hydrogen gas atmosphere of a terrestrial planet somehow detrimental to biology as we ...
20
votes
2answers
3k views

Why does Titan have an atmosphere?

Why does Titan have an atmosphere given its relatively small mass (comparable to our moon)? Why is it not lost to space or is Titan's atmosphere constantly being replenished?
6
votes
1answer
142 views

Mars greenhouse accessibility

Let's say a Mars outpost has an inflatable greenhouse. First, it is likely to be high-CO2, as CO2 is easy to acquire and increases plant growth. Second, it may be low-pressure, as plants don't need as ...
0
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0answers
242 views

Why does Earth's atmospheric density have a big “knee” around 100 km? Is there a good analytical approximation?

I've used a quick very rough approximation of the drop of atmospheric density with altitude in this answer and in this answer by using a single exponential and scale height parameter, but that's not ...
8
votes
2answers
624 views

What are the characteristics of the Earth's atmosphere near the Karman line and why?

I am wondering - what is the nature of the atmosphere in and around the transition to space at the Karman line? It is not difficult to find references using terms like "in the atmosphere" and "out of ...
9
votes
1answer
315 views

Challenging Karman line from above

Maybe I should ask this in Aviation SE, but let's try it here first, since initial conditions of the thought experiment is (very) LEO / reentry. Capsules and mostly space shuttle, generate lift in ...
0
votes
1answer
75 views

What is the meaning of twelve months for climate at Gale Crater, Mars?

I noticed that Wikipedia lists the climate on Gale Crater per “month”: Source: Wikipedia. None of the sources listed contain the information included in the table. I find it particularly puzzling ...
5
votes
1answer
258 views

Does freezing carbon dioxide present a “temperature obstacle” on Mars?

I've noticed that the average low temperature at Gale Crater is -78.5 degrees, curiously the freezing temperature of Mars' atmosphere's main component. Is that more than a coincidence? Perhaps the ...
1
vote
1answer
131 views

Smallest planet where human type life could evolve and survive?

Most exoplanets making the news are larger than Earth. I wonder about the smaller worlds, how small is too small? Reword to keep the question narrow enough to be answerable. When the Earth was ...