Questions tagged [planetary-atmosphere]

Atmospheres of planets, moons, and other solar system bodies excluding stars. For those, use "stellar-atmosphere" instead.

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What is the Milne-Eddington Approximation?

In this paper: Planet temperatures with surface cooling parameterized it states in the "radiation model" the following: The Eddington–Milne approximation relates $T_0$ and $T_e$ through the ...
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How much more mass would Mars need to currently have enough pressure for liquid water and oxygen?

My question is whether Mars just about failed to meet the threshold or missed it by a lot. It's been dry for 3 billion years. How much bigger would it have needed to be to buy it that extra time? Let'...
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Earlier references of Mars' arsia mons elongated cloud?

The weird long cloud on Mars is finally revealing some of its secrets is an article by Chelsea Gohd from space.com referencing ESA's Mars Express news. The Arisa Mons Elongated Cloud (AMEC) is ...
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When examining an exoplanet's atmosphere is the star's emission spectra or planet's light used?

My understanding of the main method we use to figure out an exoplanet atmosphere composition is that when a exoplanet transits their sun, visible light passes through the planet's atmosphere, and ...
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What is the underlying nature of the dark spot found on Uranus?

What is the nature of bright spots found on Uranus? actually quotes Space.com's Uranus Has a Dark Spot which says: During the past decade, many bright spots have been seen on Uranus in both red and ...
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Effect of particulates on the visibility of stars?

I am looking for a (mathematical) relationship - either empirical or theoretical - which quantifies how the visibility of celestrial objects decreases with increasing amount of particulates in the air....
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Did the Moon have a substantial atmosphere in the past?

The layer of gas surrounding the Moon is very thin. It is a surface bound exosphere, where particle-particle collisions are rare. In the past, the Moon was more geologically active, with eruptions ...
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What replenishes the lunar atmosphere?

It is often said that the Moon doesn't have an atmosphere. But there is an envelope of gas surrounding the Moon, albeit a thin one, so the Moon has at least an exosphere. The Moon doesn't have its own ...
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What does the amino acid found in the atmosphere of Venus mean?

An amino acid is a part of DNA, but it has only been found on Earth. Is the amino acid maybe from one of the space vehicles that has orbited, scanned, or surveyed Venus? How can a part of DNA survive ...
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Extraterrestrial snow?

What do we know about extraterrestrial snow? On which (exo)planets or (exo)moons do we have direct hints for its existance? This is indeed a children's question, but I struggle to answer it ...
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Have auroras on Titan been observed yet?

After reading the very insightful introduction to auroras on other planets I started digging and found various questions and some answers here on the same topic, see below. What I did not figure out ...
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Characteristics of Venus' jet streams?

Since the Voyager missions, the atmosphere of Jupiter received great attention, its jet streams made it into text books on geofluid mechanics, including their characteristics like the how they meander,...
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How do we get to know the total mass of an atmosphere?

Since atmospheres don't end abruptly but gradually get thinner the higher you go, I wonder how we can get the total mass of an atmosphere if we don't know where exactly it ends. E.g. the Earth's ...
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Does lightning on Venus affect the chemical composition of the clouds?

It is established that lightning occurs on Venus due to the presence of sulfuric acid clouds. Does this constant electric discharges and possible electrolysis affects the composition of the clouds on ...
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Do brown dwarfs have stripes?

Brown dwarfs (BD) are often depicted with stripes. brown dwarf Jupiter Pictures of BD resemble Jupiter but brown dwarfs ...
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What is the nature of bright spots found on Uranus?

The following text is from space.com which was written during the time of discovery of the first dark spot on Uranus: During the past decade, many bright spots have been seen on Uranus in both red ...
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Can the Sudarsky's gas giant classification be applied to ice giants?

Based on the temperature of a gas giant around another star, I have come to understand that it is possible to guestimate its appearance; a classification scheme for gas giants developed by David ...
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How are sulfuric acid clouds able to completely cover Venus?

It is a well-known fact that an opaque layer of highly reflective clouds of sulfuric acid completely shrouds Venus preventing its surface from being seen from space in visible light. This is mentioned ...
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If water vapor is always blown away into space, how is it able to create chemical compounds on Venus?

This is the follow-up of this chem.SE question. According to Wikipedia, water vapor on Venus is present in trace amount (20 ppm). There are multiple reasons why Venus has very low water content: The ...
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What other hints of possible life in Venusian atmosphere have we dismissed?

Now that phosphine has probably been discovered in relatively large quantities in the Venusian atmosphere, I heard that there have been other unexplained phenomena (i.e. dark patches) seen. Does ...
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Is dust the only reason why the Martian sky is so bright?

The atmospheric pressure on the surface of Mars is 0.00609 atm on average and 0.012 atm at most in the Hellas Basin. On Earth, at these pressures, which are found at altitudes about 30-35 km (19-22 mi)...
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Can concentration of gas in exoplanet atmosphere be found out from wavelength and absorbing radius from spectral data?

I was working on exoplanet spectral data from which I need to infer the concentration of gases. However, the exoplanet spectroscopy data contains only absorption wavelength and absorption radius. Is ...
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What is the difference between aurorae and electroglow?

One of the discoveries of Voyager 2 at Uranus was a phenomenon called "electroglow", which as I understand it is related to charged particles interacting with the atmosphere that cause the ...
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How to find the temperature of a planet accounting for the atmosphere?

Recently, I started writing a program to generate star systems, and I need a formula to find the approximate surface temperature of a planet. I know of several formulas for this, for example this one ...
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Air molecules per cubic foot at a certain altitude above the surface

The Earth's and other celestial bodies' atmospheres become thinner the higher you go. Imagine you were able to see atoms/molecules. At what altitude above the Earth's and Mars' surface would you see ...
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At what distance could a supernova damage the Earth's ozone layer?

As from my latter question it seems Betelgeuse might be much closer than the usually presumed 640 light years. It might be as close as ~440 ly. Suppose it is, would this have any dangerous effects on ...
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Why wouldn't massive torrents freeze on Mars?

I am currently reading the Cambridge Guide to the Solar System. In chapter 8, section 8.7, they explain that massive torrents of water created outflow channels on the surface of Mars in the past. The ...
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How far can we detect lightning in radioastronomy?

The wikipedia article on whistlers has this information: Voyager 1 and 2 spacecraft detected whistler-like activity in the vicinity of Jupiter known as "Jovian Whistlers", implying the ...
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Can a single impact event trigger a runaway greenhouse?

Somewhat related to this question: Is the Earth going to evolve towards Mars' fate or Venus' fate? Human civilization may be fragile, but life itself is extremely resilient, with extremophiles and ...
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Would Europa be an ocean planet if it were in the habitable zone?

If a Europa-like body were in the Sun's habitable zone, let's say in an orbit between Earth and Mars, would the body become and remain a water ocean planet? In the habitable zone, the Sun would warm ...
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How does Io's atmosphere behave locally near volcanic plumes?

Io's surface air pressure is about $0.3 {\rm mPa}$ but Io's atmosphere is strongly variable, depending on whether it's on the near side or far side of Io (relative to Jupiter) and it collapses at ...
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Which moons do have neutrospheres?

Or in other words: which moons do have ionospheres but not surface-bound ones? The space beneath an ionosphere is called a neutrosphere. I only know of Titan. I know that the Galilean moons and Triton ...
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Why is there so little nitrogen in the Martian and Venusian atmospheres?

Why don't our neighbors have much nitrogen? You would think that, without 'nitrogen-fixing' organisms and such, there might be more.....
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Is Jupiter as opaque as it looks?

Although it is impossible to tell what is and isn't false color (aside from the adage that it probably is false). It's inarguable that no picture of a gas giant shows any depth or significant ...
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Why do gas giants have clearly delineated surfaces, whereas the Earth's atmosphere fades into space?

I've just seen this Forbes article. Why do gas giants appear to have clearly delineated surfaces, whereas the Earth's atmosphere fades into space? Is it just a matter of scale? Or is there some ...
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Why doesn't Titan have a carbon dioxide atmosphere?

Earth's primitive atmosphere had large amounts of carbon dioxide, as did the ancient Martian atmosphere. Venus's current atmosphere is no exception either. So why does Titan have next to none of this ...
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How many times can iron be detected for the first time in an exoplanetary atmosphere?

I see today that there's a story about the first detection of iron in an exoplanetary atmosphere, in this case in the atmosphere of the ultra-hot Jupiter KELT-9b. I remember there being a story a ...
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Magneto tail effect on the other planet in a binary planet system

Let's say there are 2 earth sized planets orbiting each other around 750,000km apart and at a distance of roughly 1.2 AU from a sunlike star with a mass of 1.105 solar masses. Since they are binary, ...
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Could Eris have a permanent atmosphere?

In Wikipedia they write that Eris has an atmosphere when around perihelion (close to the Sun) which collapses when Eris moves away from the Sun. So it behaves similar to a comet's tail. However, they ...
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If Jupiter would stop rotating, would its atmosphere become homogeneous and single coloured?

Looking at pictures of Jupiter, there are many different colours and patterns. I imagine that the rotation has much to do with this, since there are horizontal "bands" across the planet along the ...
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Why do the upper-atmosphere clouds of Venus appear to have that V shape?

IF I understand correctly, the atmosphere moves in the same direction as the rotational spin, but about 60 times faster. It is driven from the hot side of Venus to the cold side (the difference being ...
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How does one find the electric conductivy of a planet's atmosphere?

I am working on an undergraduate project in which we study shaped structures in the atmosphere of the gas giants. We are investigating whether the magnetic field is the source of the instability ...
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Could a Jovian or Saturnian moon keep its atmosphere if the system was within the habitable zone?

Currently the atmosphere of Titan is 1.5x thicker than Earth's atmosphere, but it's also much much colder. It's been said that an astronomical body can keep it's atmosphere if the escape velocity is ...
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Why does Titan have an atmosphere while similar moons such as the Galilean moons don't?

The Galilean moons of Jupiter are similar in size to Titan and are also protected by their parent planet's magnetic field. How come only Titan is able to maintain an atmosphere?
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Why is Saturn invisible in this radar image of its rings?

The image below is from Radar imaging of Saturn’s rings Nicholson, P. D. et al., Icarus 177 (2005) 32–62, doi:10.1016/j.icarus.2005.03.023 and discussed further in this answer to How did Arecibo ...
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How thick was Earth's primordial atmosphere?

Earth's first atmosphere was made of hydrogen and helium accumulated before fusion started in the Sun. As soon as this happened it was stripped away by the Sun. How many atm of hydrogen and helium had ...
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When and where are we exposed to most cosmic radiation?

I understand the mechanical dynamics of being faced away from the Sun at night, having a lower altitude, not being in the weak points at the poles in the atmosphere, being in a valley and others ...
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What if the atmosphere of Titan were like the one on Venus?

The current mean temperature in Titan is −180 ºC (93 K), the same as in Saturn. But I was wondering what would be the case if the atmosphere of Titan would be like the Venus atmosphere, whose ...
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Do we know of any tidally-locked planets with atmospheres?

If not, is there any reason such a planet couldn't exist? I ask only because that planet would literally have a twilight zone and I want to know that that's a thing somewhere.
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What would happen to the atmosphere of a rogue jovian planet?

Let's say we have a gas giant composed primarily of hydrogen and hydrogen-rich molecules that is ejected from its star system. As this planet embarks on its potentially infinite journey out into the ...