Questions tagged [atmosphere]

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

Filter by
Sorted by
Tagged with
22
votes
5answers
3k views

Does upper atmosphere rotate with earth?

Basic question that I should know the answer to but sadly don't. The lower atmosphere must rotate with the earth because of friction---at least the very bottom of it. But what about 30 miles up? There ...
0
votes
0answers
29 views

Still trying to understand “knee” in Earth's atmosphere >100 km; if pure Ne or Ar would it still be there when MFP exceeded scale height?

There is currently one answer to How many solar system bodies have "knees" in their atmospheres? that points out that somewhere above roughly 100 km turbulent mixing drops off (thus the name ...
0
votes
1answer
87 views

How many solar system bodies have “knees” in their atmospheres?

Discussion lead to citing Why does Earth's atmospheric density have a big "knee" around 100 km? Is there a good analytical approximation? who's answer is "monatomic oxygen". ...
5
votes
2answers
814 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 ...
4
votes
1answer
150 views

Did the Space Shuttle crew have to worry about the ionosphere? What relevant training or specific briefings did they receive?

Comments below this answer tell us that the Space Shuttle always remained in Earth's atmosphere. When it visited the Hubble Space Telescope or the ISS or Mir it was still in the thermosphere and ...
54
votes
3answers
7k views

Why did it take so long to notice that the ozone layer had holes in it? Which satellite provided the data?

Wikipedia says: The discovery of the annual depletion of ozone above the Antarctic was first announced by Joe Farman, Brian Gardiner and Jonathan Shanklin, in a paper which appeared in Nature on May ...
65
votes
4answers
16k 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,...
2
votes
0answers
38 views

Why is Ozone hole above single area of earth? Why that area? [migrated]

As titled. How does the hole fell specifically on that region of the stratosphere above the Antarctic and why?
6
votes
1answer
272 views

How long could an oxygen/nitrogen atmosphere last on the Moon?

So, if the Moon had an atmosphere composed of oxygen and nitrogen, how long might it last before it all boiled off into space due to the low gravity of the Moon? Or better yet, a krypton or xenon ...
6
votes
1answer
411 views

Could the Moon be terraformed by outgassing its oxygen?

The majority of the Moon's mass is oxygen. With energy it could chemically be liberated from its silicon et cetera compounds and be turned into oxygen gas. Given its low gravity, lack of magnetosphere ...
35
votes
5answers
17k views

Would a settlement on Mars need to import Nitrogen?

The air on Earth is about 20% oxygen and about 78% nitrogen. Best case, there seems to be sufficient oxygen (in water) to support colonization in the polar ice caps. What about the other 4/5 of the ...
0
votes
1answer
155 views

How to calculate the pressure at the floor of Ganges Cavus on Mars when it is filled to its edge with perfluorobutane?

Perfluorobutane is an inert, high-density colorless gas and has a high Global Warming Potential value of 4800. At about the same temperature of -1.7 ⁰C, it has a density of 11.2 kg/m3, opposed to 2 kg/...
48
votes
2answers
8k views

What impact will the deorbiting of thousands of satellites have on the atmosphere?

With the creation of mega satellite constellations like Starlink, there are several thousand satellites being launched each year. This means that as these satellites go out of order in a few years, ...
5
votes
1answer
117 views

Where can I learn to calculate the physics of an ion thruster?

I am trying to build an ion thruster, but I don’t know where to start learning the actual numbers behind one. I know how they work on a basic level, but not much more. Basically I want to be able to ...
5
votes
2answers
139 views

How is atmospheric temperature measured from a satellite?

How does an Earth observing satellite measure the temperature of the atmosphere? Can they measure temperature at multiple altitudes, or measure the temperature of clouds?
1
vote
0answers
24 views

How do you balance speed and exposure time when trying to reduce heating? [duplicate]

I'm trying to understand how you choose your acceleration/deceleration and trajectory during launch and reentry to minimize aerodynamic heating.* Ignoring efficiency in terms of delta-v (best leave ...
1
vote
0answers
68 views

g-forces entering and leaving atmospheres, how would they vary from one body to another?

I was wondering how launching from and returning into atmospheres of other bodies such as Mars, Venus, Titan, etc. would differ from Earth's. Specifically, I am wondering how many g's would be ...
2
votes
1answer
57 views

Orbit lifetime of a Nano-Satellite in 350 Km Orbit

I was trying to write a very simple program to calculate orbit life time of a nano-satellite. I got the atmosphere density as function of altitude from this site. ...
2
votes
0answers
149 views

How did three 1.2 meter spheres and a Xe+ plasma contactor keep the Shuttle “grounded”? What did they look like?

Statement of relevance This answer to Highest DC voltage ever intentionally produced in space? mentions particle beam experiments done from the Space Shuttle while it flew through Earth's atmosphere ...
4
votes
2answers
149 views

How much energy from the Sun could we get if we use Jupiter or the Earth as an atmospheric lens?

How much energy (watts) from sunlight could arrive to the focal point if we use Jupiter or the Earth as an atmospheric lens by using refraction? How far the focal point would have to be placed for ...
12
votes
3answers
446 views

Phosphine, yes — but where are the organic compounds on Venus?

There has been much speculation in recent news about the finding of phosphine on Venus, and what may be producing it. At the same time, when we look for clues of life elsewhere in the Solar System, we ...
9
votes
2answers
370 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
1answer
215 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% ...
1
vote
2answers
117 views

Could one use an adjusted idealized greenhouse model to calculate the local average temperature on Mars?

The Idealized greenhouse model article on Wikipedia gives the following solution for finding the global surface temperature on an idealized planet with an atmosphere: $$T_s = \left[ \frac{S_0(1 - \...
3
votes
1answer
165 views

Did the Space Shuttle crew have to worry about monatomic oxygen?

Comments below this answer tell us that the Space Shuttle always remained in Earth's atmosphere. When it visited the Hubble Space Telescope or the ISS or Mir it was still in the thermosphere and ...
12
votes
0answers
380 views

How does it feel to breathe 100% oxygen at low pressure?

Some space suits are designed to provide an atmosphere of 100% oxygen but at a reduced air pressure about 20% that of sea level. Is breathing in such a suit uncomfortable? It seems like having such a ...
2
votes
0answers
129 views

What exactly is electron precipitation in Earth's ionosphere and how does it relate to the STEVE phenomenon? [closed]

Source Trying to decide if the unanswered question What was Steve? Is it called something else now? is in need of attention I checked Wikipedia's Steve (atmospheric phenomenon); Occurrence and cause ...
1
vote
0answers
66 views

How bright is twilight on Mars compared to Earth?

The surprising answer to How much more quickly does night come on Mars compared to Earth? Will it be easier to see Mercury there? is "up to two hours(!)" "...indicating that Martian dust extends very ...
5
votes
1answer
331 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. But the ...
10
votes
2answers
2k views

How much sulphuric acid is on Venus?

According to Wikipedia there are just 150 ppm of sulphur dioxide and 20 ppm of water in Venus' atmosphere. At the same time it is known that there is a considerable amount of sulphuric acid in the ...
2
votes
0answers
201 views

Have any Apollo (or earlier) astronauts reported seeing Earth's aurora or related luminescent atmospheric effects?

Earth's aurora and related luminescent atmospheric effects are generally quite dim, and mostly but not always located in the general area of Earth's magnetic poles. That means to be seen easily by eye ...
4
votes
1answer
87 views

What is the Opaque Component of Venus' Atmosphere

My understanding is that carbon dioxide makes up the majority of the Venusian atmosphere, and carbon dioxide is transparent. Even liquid CO2 is transparent! Yet despite this Venus is enveloped in a ...
15
votes
3answers
2k views

Is it more challenging to put an airship in the Uranian than in the Venusian atmosphere?

The Soviet Union's (in cooperation with some European governments like France and West Germany) Vega missions put balloons in the atmosphere of Venus back in 1985. It was 30 years ago, the last ...
3
votes
1answer
591 views

Have any Soviet-era astronauts reported seeing Earth's aurora or related luminescent atmospheric effects?

Earth's aurora and related luminescent atmospheric effects are generally quite dim, and mostly but not always located in the general area of Earth's magnetic poles. That means to be seen easily by eye ...
6
votes
4answers
551 views

Is there likely to be life in Venus's upper atmosphere?

From what I understand, Venus's upper atmosphere is much more habitable than its surface, with a temperature and pressure that humans could tolerate. However, lack of oxygen and the presence of ...
15
votes
1answer
2k views

Why wasn't the phosphine in Venus' atmosphere detected by space probes?

Today, it was announced that phosphine has been found in Venus' atmosphere, rekindling the discussion about the possibility of extraterrestrial life. Venus has been visited by space probes for about ...
9
votes
1answer
508 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
2answers
66 views

How were the boundaries of LEO and MEO (or all geocentric orbits) determined?

From my understanding: Low Earth Orbit is from 100 - 1240 miles. Medium Earth Orbit is from 1240 - 22246 miles. High Earth Orbit is from 22246 and above. What ...
0
votes
0answers
69 views

How to calculate how deep a crater on the Moon has to be to have liquid perfluorodecalin on its floor?

Because the Moon has no atmosphere, one could be created by the sublimation or evaporation of a solid or a liquid respectively, within a deep crater if the gas would not flow over the rim. ...
6
votes
2answers
1k views

Exactly how “Ferrari-like” was GOCE? Was its drag coefficient as low as the car's?

This comment mentions: This relation between drag and mass is taken to a relative (for satellites) extreme in GOCE which I think needed to be close to Earth to accurately sense the changes in gravity,...
12
votes
3answers
822 views

Strategies for combating ESD and ground plane potential shifts on spacecraft charging?

What are some common design guidelines/practices to combat the electrical effects of spacecraft charging(e.g. ESD, ground plane shift). Is it to focus on more resilient parts, and reduce resistance/...
5
votes
1answer
132 views

Would a spacecraft landing on Io need a heat shield?

Io is Jupiter's only moon with a considerable atmosphere. Its atmosphere is extremely thin (up to 40 nbar) which obviously is too thin to use a parachute. However a spacecraft would maybe need a heat ...
5
votes
1answer
272 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 ...
7
votes
1answer
385 views

What would be the challenges for a 50 km long tether to the surface of Venus to get recurrent surface samples there?

Basalt fiber would be an excellent material for a tether in the atmosphere of Venus because it could withstand both the acidity and the high temperature near the surface there. From this answer about ...
23
votes
9answers
10k views

If someone built a vacuum tunnel through the atmosphere, could you have an orbit with a sea level perigee?

This is something I've been thinking about for a while now. My initial estimates for the structure were based on people's estimates for an O'Neil cylinder, but assuming you can make the structure a ...
74
votes
3answers
43k views

What will be the effect if we stand on Jupiter?

As we all know Jupiter is a gaseous gas giant and it has a large mass, almost twice the sum of all other planets in the Solar system. So, if it happens that we go to Jupiter, and, as we know it does ...
4
votes
0answers
94 views

How sharp are the bits of sand and rock on mars?

Lunar regolith is quite sharp, so abrasive it can cut kevlar. This is because there is no flowing water or substantial atmosphere to erode the material and smoothen it out, so meteorite impacts break ...
11
votes
3answers
732 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 ...
13
votes
1answer
402 views

Are there microclimates with better weather conditions on Mars?

On Earth, a microclimate mostly refers to an area which differs from the surrounding areas in temperature or humidity. And what about Mars ? Are there places with atmospheric conditions that are less ...
3
votes
1answer
56 views

Upper atmospheric studies in 1930/1940

I understand that during 1930/1940s, Baloons were used to gather high altitude data like "pressure" or "temp." I wonder how the instruments "recorded" their data? E.g. ...

1
2 3 4 5 6