The study of the composition or dynamics of the gaseous layers around planets, often applied to questions on Earth's atmosphere but can be applicable to all planets & moons in the solar system.

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8answers
23k views

Why does the atmosphere rotate along with the earth?

I was reading somewhere about a really cheap way of travelling: using balloons to get ourselves away from the surface of the earth. The idea held that because the earth rotates, we should be ...
32
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4answers
6k views

Why is the sky never green? It can be blue or orange, and green is in between!

I, like everybody I suppose, have read the explanations why the colour of the sky is blue: ... the two most common types of matter present in the atmosphere are gaseous nitrogen and oxygen. ...
32
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3answers
6k views

Why is the sky not purple?

I realise the question of why this sky is blue is considered reasonably often here, one way or another. You can take that knowledge as given. What I'm wondering is, given that the spectrum of ...
31
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9answers
7k views

Why can't we see gases?

I am not sure what causes gas molecules to be invisible.This question may look silly but I really want to know the story behind it.
26
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2answers
3k views

Why is the sun brighter in Australia compared to parts of Asia?

Background: I've lived in Philippines for several years, and visited other parts of Asia occasionally (Singapore, Indonesia, Hongkong). I just moved to Western Australia a few months ago and I ...
25
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3answers
3k views

Why doesn't rain fall down in streams (as opposed to drops)

Why is it that raindrops don't collide and 'stick together' on their descent to Earth, arriving in streams rather than separate drops?
21
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3answers
2k views

Why do the storms of Jupiter have long life unlike that of Earth?

Recently I saw How the Universe Works. In one of the episodes, concerning Jupiter, they told that the storms on Jupiter can survive many, many, times longer than those on Earth. What is the reason ...
21
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4answers
514 views

Why is lightning more rare during snow storms than rain storms?

Lightning and thunder during a snow storm is uncommon. As far as I know, more uncommon than during a typical rain storm. Why is this? I speculate it might be one, or both, of the following two ...
20
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3answers
828 views

Are the air particles in today's wind on earth (more or less) the same as the air 2/3 billion years ago?

So the air pressure on earth remains relatively constant, right? Is there air gained or lost through transitions of any sort? e.g. plumes going out into space, earth gaining new air particles with ...
20
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1answer
1k views

Can rain evaporate?

Are there any atmospheric condition under which a visible raindrop can fail to hit the ground by evaporating first? I imagine this would require a large vertical temperature difference, and possibly ...
19
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1answer
487 views

Causes of hexagonal shape of Saturn's jet stream

NASA has just shown a more detailed picture of the hexagonal vortex/storm on Saturn: http://www.ibtimes.com/nasa-releases-images-saturns-hexagon-mega-storm-may-have-been-swirling-centuries-1496218 ...
17
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3answers
541 views

Why don't more rocky planets/moons have appreciable atmospheres?

It seems obvious why mercury has no atmosphere, given its proximity to the sun--but yet Venus is also fairly close, and has an extremely dense atmosphere. Titan is a large moon with an atmosphere ...
17
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2answers
1k views

If I shout at the sky, will some molecules reach escape velocity?

Will the sound waves, as they move higher and through less dense air, conserve energy to the point where some molecules of the rarified atmosphere attain escape velocity?
16
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2answers
683 views

How deep is the Great Red Spot?

The Great Red Spot (GRS) is a very persistent storm system that's easily visible through a telescope on the surface of Jupiter. But what is the three-dimensional structure of the GRS, and how deep ...
15
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3answers
3k views

Does a man on the moon experience day?

Does a man on the moon (or any other similar body) experience daytime like we do? By daytime I mean looking upward and seeing a bright "sky," not dark space. If not, then what is the reason behind ...
15
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5answers
2k views

Can Helium Disappear from Earth?

Can Helium disappear? As we know Helium is lighter than air, so basically Helium fly off from Earth. Is it possible that in the future we will run out Helium?
15
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10answers
4k views

Why do space crafts take off with rockets instead of just ascending like an aircraft until they reach space?

I guess it's not a very educated question, but I never quite understood why spacecrafts have to shoot up and can't just reach space by simply continuing an upwards ascent like an airplane.
15
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2answers
1k views

Why does my infrared thermometer say the sky is at -2 °C?

I just got myself an infrared thermometer. I wouldn't have been able to predict what temperature it would give me when pointing at the sky, but it turned out to be -2 °C the first time I measured, and ...
13
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2answers
368 views

Why is Jupiter so sharply defined?

In photographs of Jupiter, the limb seems extremely definite. Being a gas giant, my naive self thinks that the atmosphere should have a more gradual cut off, creating a hazy effect similar to that on ...
13
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1answer
2k views

From how high could have Felix Baumgartner jumped without disintegrating like a shooting star?

Today Felix Baumgartner jumped from 39 kilometres high and reached the earth safely. Just considering friction, from how high can a human jump? I expect that from a certain height, he would have ...
13
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2answers
246 views

Why do clouds form in lumps?

What forces drive the water vapor to form the shapes every child draws? Why isn't water vapor forming an uniform mist layer consistently (which it some times does)? I have two general ideas how this ...
12
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4answers
32k views

Why does the road look like it's wet on hot days?

Often, I'll be driving down the road on a summer day, and as I look ahead toward the horizon, I notice that the road looks like there's a puddle of water on it, or that it was somehow wet. Of course, ...
12
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4answers
738 views

How Earth protected from the gamma rays generated by Sun?

Sun is generating energy by nuclear fusion. And nuclear fusion will emit energy in the form of gamma rays. Normally earth's ozone filtering the Ultraviolet radiation. And magnetic fields of earth ...
12
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1answer
4k views

Did Felix Baumgartner produce a sonic boom during his jump?

I really got to thinking about this. The speed of sound is measured at 761.2 MPH at sea level. But how does this number change as air density decreases? The lack of air density is what allowed his ...
12
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2answers
4k views

Is there an upper frequency limit to ultrasound?

Wikipedia has this diagram of the acoustic frequency spectrum: Is there an upper limit to the frequencies you can transmit through the air? Are they absorbed more and more at higher frequencies, ...
12
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2answers
347 views

How are the northern lights produced?

Although I've never seen it myself, I hear the northern lights are a sight to be seen! I know they're related to the Earth's magnetic field but I don't know much more about them. What is the physical ...
12
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1answer
173 views

What is the current physical theory of what causes the 'Morning Glory' roll cloud over Northern Australia?

The Morning Glory roll cloud (pictured below): from this Wikipedia page, which briefly describes the landform and meteorological causes, but states The Morning Glory cloud is not clearly ...
11
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3answers
3k views

If I were standing on the surface of the sun, how far could I see?

Assuming it would be possible to handle the intense heat... Is the surface even? If not, would average surface elevation be an appropriate definition of "surface"?Does the sun have an atmosphere that ...
11
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4answers
4k views

Why can't CO2 mix back with the liquid after a soda bottle has been shaken?

If you shake a soda bottle before opening it, and then open it, you get the fizz. That is the compressed CO2 releasing to the atmosphere which is at comparatively low pressure value. Two questions ...
10
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5answers
9k views

Why less temperature at high altitude

Why there is always cold at high altitudes. e.g. at peak of mountains. Also as we go high from sea level, temperature starts decreasing. Why is it?
10
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5answers
994 views

Can low-gravity planets sustain a breathable atmosphere?

If astronauts could deliver a large quantity of breathable air to somewhere with lower gravity, such as Earth's moon, would the air form an atmosphere, or would it float away and disappear? Is there a ...
10
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2answers
336 views

Is this a weather phenomenon or an instrumental artifact?

The radar image of the midwest provided by Weatherunderground at 10:30 PM Central time, May 8 2011 has odd patterns. Are these patterns real? Perhaps caused by large scale convection over cities? Or ...
10
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2answers
505 views

Energy from man-made tornadoes

Peter Thiel just paid $300,000 to Canadian inventor Louis Michaud who is working to construct useful "man-made tornadoes" or "atmospheric vortex engines" which could be components of future power ...
9
votes
1answer
408 views

What causes a ring-like image around light of the moon?

I just encountered an interesting image in sky. As you can see in following images there was a ring-like image around light of the moon. I don't know if it was clouds but it was looking like it is far ...
9
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2answers
284 views

Why do clouds fly? [duplicate]

I know it's probably the most stupid question there is, but why do they fly are the clouds lighter than air? What's keeping those tiny ice structures floating miles about the ground? I've been looking ...
9
votes
4answers
11k views

How does carbon dioxide or water vapour absorb thermal infra red radiation from the sun?

We are all told at school water vapour and carbon dioxide are the top two greenhouse gases, and that they absorb thermal infra red radiation, trap heat and warm up the Earth. My question is how do ...
9
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0answers
83 views

Does anyone know the mechanism behind this double helix cloud formation?

This looks like m=2 swirling instability mode of the axisymmetric jet, but how could an axisymmetric jet form up in the sky like that?
8
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2answers
580 views

Why doesn't the percentage of oxygen in Earth's atmosphere diminish significantly with altitude?

According to numerous sources online, the percentage of oxygen is approximately the same at sea level and 10,000 meters. Since oxygen is heavier than nitrogen, shouldn't the percentage of oxygen ...
8
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3answers
385 views

Extended sound of thunder

Why does the sound of thunder last several seconds even when lightning lasts for only fraction of a second?
8
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3answers
938 views

How is it that the Earth's atmosphere is not “blown away”?

The Earth moves at a high rate of speed around the Sun, and the solar system is moving quickly around the Milky Way. How is it that the Earth's atmosphere is not “blown away”?
8
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3answers
2k views

What would happen if the polar ice caps of Mars melted?

My dad told me that Mars' polar ice caps are made of H2O and CO2. If they melt, would it add an atmosphere to Mars and allow life?
8
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1answer
75 views

Do we have 2 minutes of extra morning?

my physics teacher told me about the refraction and its applications one of them was 2 minutes of early sunrise and after she explained this effect she concluded that days are 2 minutes longer than ...
8
votes
1answer
127 views

'Hole in the clouds' in the Sarychev Peak eruption

One of my favourite ever pictures taken from space is a picture of the 2009 eruption of Sarychev Peak (Ostrov Matua island, Japan) taken by an ISS astronaut during a lucky fly-over. Image Source: ...
8
votes
1answer
71 views

What is the reason of the semidiurnal pressure oscillation in the atmosphere?

It appears that in many (most) places on earth, a pressure oscillation of a 100-200 Pa takes place twice a day : that is, with maxima around 12AM and 12PM and minima around 6AM and 6PM. I've found ...
8
votes
1answer
51 views

How does the atmospheric UVB attenuation of terrestrial planets compare?

On Earth, UVB (280nm - 315nm or 320nm depending on the source) undergoes extensive attenuation through the atmosphere, when observed at the planet's surface, as illustrated below: Image source ...
7
votes
4answers
560 views

Can a small change in the Earth temperature give rise to large-scale climate changes?

Earth's atmosphere is a chaotic system. In such systems arbitrarily small changes the conditions can give rise to very large effects. There are many rumors about the physical and large scale ...
7
votes
5answers
1k views

What would ACTUALLY happen to a person jettisoned into space?

[insert obligatory statement of my lack of knowledge in physics] Alright, so we have all seen the movies where someone gets blasted out of the airlock on their starship, or their suit decompresses ...
7
votes
2answers
4k views

The Density of Clouds

Clouds are made up of tiny water or ice droplets, depending on temperature. This implies that cloud density is greater than that of dry air. Why don't clouds sink through their surrounding atmosphere ...
7
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2answers
107 views

Why do the terrestrial planets have many of the same gases in their atmospheres?

While the gases are present in very different abundances, and the atmospheres have very different pressures, Earth, Mars and Venus all have a similar cast of gases: nitrogen, argon, CO2, others in ...
7
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2answers
1k views

Why is getting a tan in the evening less likely than getting a tan in the morning?

When I was young I read one book in which is written that you get more tan on the morning than on evening even light angle from Sun to Earth is the same. Don't remember exact reason, I think because ...