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22 votes
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Why doesn't Titan have a carbon dioxide atmosphere?

The chemistry of Titan's atmosphere is complex, with reactions occurring between carbon dioxide, oxygen, carbon monoxide, hydroxl, and other compounds. This means that carbon dioxide production and ...
HDE 226868's user avatar
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19 votes
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Is the water underneath Europa's ice cap potable?

According to this 2007 paper, the current research as of the time of their own research had a huge range in possible concentrations of $\text{MgSO}_4$, magnesium-sulfate, with over four orders ...
zibadawa timmy's user avatar
15 votes

Why can't 'dead' galaxies start forming stars again if they merge with another, 'active' galaxy?

It is not true that "dead", or quenched galaxies cannot start forming stars again. It is called rejuvenation and is observed occasionally (e.g. Chauke et al. 2019), although not commonly (...
pela's user avatar
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14 votes

Is there a way to tell the difference between earth andesite from Mars

If this is something that you have found (rather than purchased as a meteorite) the chances are very small that it is a meteorite. Even if it is a meteorite, the chances it's a Martian one are even ...
astrosnapper's user avatar
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10 votes
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What factors influence the Widmanstätten pattern in iron meteorites?

It’s been a while since I studied this, and meteorites are very much not my field, so I’ll share my current understanding but would welcome corrections from those more informed :-) These meteorites ...
Matthew's user avatar
  • 288
9 votes
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Why was helium hydride (HeH+) the universe's first molecule?

At the risk of self-plagiarism: (https://physics.stackexchange.com/a/532568/43351 with a bit added). Molecular chemistry in the early universe requires species with bound electrons. Helium hydride is ...
ProfRob's user avatar
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9 votes

Acetylene at Uranus? What's JWST's evidence and current thinking of how it's possible?

I think part of the issue here is that you seem surprised to learn that JWST detected acetylene in the atmosphere of Uranus, as though this is both unexpected and merits a certain amount of skepticism ...
Peter Erwin's user avatar
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8 votes

Has THC been detected in space?

The detection of complex organic molecules, often abbreviated as COM in astrochemical literature, has only taken up pace in the last couple of decades since substantial advances were only made ...
Diazenylium's user avatar
8 votes

Are sulfur and phosphorus also created in the nucleosynthesis of big stars?

It is not true to say that the CNO cycle produces these elements. It is more like a catalytic chain that aids the conversion of hydrogen to helium. Thus pre-existing CNO nuclei are required and all ...
ProfRob's user avatar
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8 votes
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How does this comet have alcohol in it?

Getting atoms together into molecules requires two basic things - getting the reactants together and them providing the means to overcome the "activation energy" that is due to the mutual repulsion of ...
ProfRob's user avatar
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6 votes

Is the water underneath Europa's ice cap potable?

Since water on all planets is in contact with impurities, I would think that the default for water is salty, and a small percentage on Earth (2.5%) gets desalinated by going through the evaporation/...
antlersoft's user avatar
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6 votes
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Why do these astronomers say that "Carbon chains with more than nine atoms are unstable"?

Unlike the saturated hydrocarbons in kerosene, carbynes are unsaturated carbon chains with alternating single and triple bonds. Molecules containing such chains are called polyynes, e.g. the short ...
Mike G's user avatar
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6 votes

Acetylene at Uranus? What's JWST's evidence and current thinking of how it's possible?

A compilation of the known compositions of the gas giant planets (by number density), compiled from several sources indicated in the table, is given Lodders 1. References cited in the table [2-6] are ...
Oscar Lanzi's user avatar
  • 1,141
5 votes

Is the water underneath Europa's ice cap potable?

The most popular hypothesis for explaining the various zigzagged lines (lineae) that cover Europa’s surface is that they are caused by cracks appearing in the ice shell because of tidal deformations, ...
Pierre Paquette's user avatar
5 votes

Diamonds in Neptune?

People have demonstrated high-pressure diamond formation using laser-driven shocks, much in line with the original idea. The diamond rain idea seems to be doing well (popular science article about it, ...
Anders Sandberg's user avatar
5 votes
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What is germane doing in the atmosphere of Jupiter?

How much specific elements sink inside a planetary caldron with variations of heat and thermals and chemistry, depends not just on their density but also the element's chemistry. This question ...
userLTK's user avatar
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5 votes
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What aliphatic compounds were found on Ceres, and how where they identified?

OK, I did a bit of research on this. The LA Times article you quoted says something a little bit useful. While the scientists aren’t sure exactly what the compounds are, the fingerprint is ...
userLTK's user avatar
  • 24.1k
5 votes
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Is there any difference among exoplanets in composition due to host star?

The chemical makeup of space dust -- the stuff which agglomerates into planets -- is dependent on the history of supernovas and neutron stars and the like which created the atoms in a given region of ...
Carl Witthoft's user avatar
5 votes

Are sulfur and phosphorus also created in the nucleosynthesis of big stars?

Yes, they are created through stellar nucleosynthesis. Sulfur is created from silicon via an alpha process, with the reaction $$_{14}^{28}\text{Si }+\text{ } _2^4\text{He}\to _{16}^{32}\text{S }+\...
HDE 226868's user avatar
  • 37.1k
5 votes
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What if you lit a fire on a planet whose atmosphere consists of 50% oxygen and 50% a flammable gas?

A minor note, but for maximum burnage, you'd want 75% Oxygen. 3 O2 + 1 CH4 -> 1 CO2 + 2 H2O. An atmosphere of that composition is impossible because chemistry happens. Oxygen and Methane ...
userLTK's user avatar
  • 24.1k
5 votes
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What is the meaning of integrated emission maps for these chemical species?

Those are plots of the real spatial distribution of flux at certain frequencies, as it appears on the sky. The latter can be seen as the x-y axis in each individual plot refer to the declination and ...
AtmosphericPrisonEscape's user avatar
4 votes

Is the composition of stars in future made of more and more heavy elements?

The initial stars were made of hydrogen and helium. These enriched the interstellar medium (ISM) with some chemical elements right across the periodic table, when massive primordial stars ended their ...
ProfRob's user avatar
  • 155k
4 votes
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Does lightning on Venus affect the chemical composition of the clouds?

Observations by many spacecraft that have visited Venus over the last 40 years appear to confirm the presence of lightning storms in the Venus atmosphere. Recent observations by Venus Express indicate ...
Nilay Ghosh's user avatar
  • 4,695
4 votes

How diverse are chemical reactions outside Earth?

Yes! It just depends on this main factors that affects whether a reaction will take place or not: Gibbs free energy Gibbs free energy $G$, is a determiner of whether a reaction takes place ...
DialFrost's user avatar
  • 2,115
3 votes
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Air molecules per cubic foot at a certain altitude above the surface

The kinds of molecules / atoms and the density of those molecules / atoms as a function of altitude in the Earth's upper atmosphere depends very much on the time of day and the activity of the Sun. ...
David Hammen's user avatar
  • 34.1k
3 votes

Are there examples of the effect of shock waves on chemical evolution in of interstellar medium or circumstellar medium?

Shock waves in the interstellar medium (ISM) can be caused by a spiral density wave, supernova shock, or turbulent flow collision. These waves sweep, compress and heat the ISM, thus modifying which ...
usernumber's user avatar
  • 17.6k
3 votes

Is there a way to tell the difference between earth andesite from Mars

Only two meteorites have been found on Earth that are composed of andesite. They were found at the Graves Nunataks ice shield in Antarctica during a US Antarctic search for meteorites in 2006/07. The ...
Fred's user avatar
  • 2,169
3 votes

What does a black hole elements consists of?

If your question is "What elements are in a black hole?" The answer is: The gravity is too great for there to be "elements" (atoms or molecules) inside or near the surface of a ...
Rob's user avatar
  • 2,666
3 votes

If there are neutron stars, would most stars be considered "proton stars"?

The analogy is false. Neutron stars consist mainly of neutrons, with a small fraction of protons and electrons in equal numbers. The fraction is density dependent, but is in the range 1%-10%.$^{*}$ ...
ProfRob's user avatar
  • 155k

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