6
votes
2answers
81 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 ...
6
votes
0answers
37 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 ...
17
votes
1answer
423 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 ...
-2
votes
1answer
101 views

Why do planets other than earth have colours?

I know Mars has many red rocks and mountains. But since it does not have any atmosphere, it shouldn't have any color. So, why does it appear red?
2
votes
2answers
89 views

Does gravity affect radiation incident on the planet?

Just curious ... Known facts: When outside the atmosphere levels of radiation are higher Typically such radiation is CBR, Solar Radiation Question: If the matter of the atmosphere and ...
0
votes
0answers
50 views

Why stars twinkle but planets don't? [duplicate]

I am not from a physics background. I came to know this while studying probability? Is this because the planets are nearer than the stars so we get average behaviour rather than random. Is law of ...
3
votes
1answer
105 views

Has martian sunset same spectra than this earthly bluish-violet sunset?

Has martian sunset same spectra than this earthly bluish-violet sunset? What about sunset on Mercury?
6
votes
1answer
174 views

Atmospheric Circulation

What is the simplest simulatable model giving our rotating earth its 3 circulation cells (Hadley, Ferrel, Polar)? The model should also show 1 circulation cell if the earth's rotation were stopped (or ...
16
votes
2answers
484 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 ...
2
votes
0answers
161 views

What is the critical mass of a planet to have an atmosphere like Earth's?

Small planets/orbits like Moon cannot have atmosphere because of their masses. They don't have enough gravity to hold an atmosphere. Then what is the critical mass that makes enough gravity to keep an ...
5
votes
2answers
2k views

What does the phrase “limb of the earth” or “atmospheric limb” mean?

What does the term limb of the earth (see this question, for example) or atmospheric limb mean? The phrase strikes me as very odd, since earth is nearly spherical. Do other planets with atmospheres ...
0
votes
1answer
528 views

Atmospheric Escape of Gas Molecules

Most of the Bodies and Objects in space are likely to have an atmosphere. Since the space is empty, the gases in atmosphere should have either dissolved or emptied into space. But, Why doesn't this ...
0
votes
2answers
123 views

Atmosphere above huge fire areas (e.g., “fire ocean”)? [closed]

My question is more about climate sciences, but I hope that it is still related to physics. What would be possible atmospheric conditions for planet with some kind of "fire" ocean? I had some ...
3
votes
1answer
155 views

Keeping air in a well

Let's say I've got an Earth-like planet with no atmosphere: it's just a barren ball of rock. I want to live there, but I don't like domes, so instead I'm just going to dig a big hole and let gravity ...
3
votes
1answer
693 views

Altering Venus rotational speed to match Earth's via weather manipulation

Venus rotates approximately 6.5 km an hour Earth rotates approximately 1650 km/h how fast could we speed up Venus's rotation via only weather manipulation ( maybe a giant fractal lens between Venus ...
3
votes
1answer
22 views

For the long-term evolution of atmosphere/orbit, when is perihelion more important than mean distance?

When we want to figure out the long-term evolution of a planet's atmosphere/orbit, when is perihelion more important than mean distance? E.g. some processes (like Jeans Escape and escape of ...
6
votes
3answers
411 views

Why is the surface of Venus so hot?

Whenever I have seen Venus described, its high surface temperature is attributed to an intense greenhouse effect. This seems to make sense, as its atmosphere is roughly 96% CO2. But on Earth, the ...
8
votes
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?
16
votes
3answers
492 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 ...