Questions tagged [planetary-science]

The multi-disciplinary study of the geomorphology, geology, chemistry, meteorology, oceanography, hydrology, astronomy and astrophysics of the planets and other objects within the solar system.

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Why are there no tholins in the inner solar system?

There’s plenty of carbon dioxide and radiation throughout the solar system, why is it a phenomena only associated with the outer planets?
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Calculate original volatile content of a degassed mineral

A lunar apatite sample has a relatively low OH content of 5 ppm, but a an elevated D𝛿 of 11,000‰ (vs. SMOW). Assuming that water had an original figure of around -100‰ or so, how do I estimate the ...
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Why is the Lunar crust anorthite?

The primordial Lunar crust is mostly calcic plagioclase. However, why did the Lunar Magma Ocean produce so much anorthite, why not a feldspar of a different composition, like albite or orthoclase for ...
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What does fugacity mean in the context of geology?

I am reading about water in the Lunar mantle, however it mentions fugacity a lot. What does it mean in this context?
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What is the difference between a depleted mantle, and a fertile or enriched mantle?

In a paper about the interior of the Moon, it references depleted mantle sources and enriched mantle sources. Sometimes the latter is referred to as 'fertile'. What is difference between the first two?...
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What would the climate and greenhouse effects be if the oceans contained half as much water?

Imagine the Earth contains 50% the water it currently contains. The oceans are still located in the same place, but they are much shallower. How would this affect the climate and the climate stability ...
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How might 25% lower gravity affect precipitation on an Earth-like planet? [closed]

I'm working on a science fiction project and hoping someone who knows something about climate can answer this question for me: if Earth had 25% less gravity, how would that affect precipitation? I ...
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Do scientists ever make rock vapor in a laboratory? If so, is it ever used to study planetary or lunar formation?

This answer to What is the nature of "rock vapor" in this description of the formation of the Moon? explains what "rock vapor" is and how scientists use the concept to understand ...
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If Earth's axis wasn't slanted, would all earth be tropical? [duplicate]

If Earth's axis wasn't slanted, would all Earth be tropical due to even scattering of sun light beams all over the planet? Of course, the poles would still be cold, even colder, but earth in general ...
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What is the elevation angle of sun at lunar poles?

The Moon's orbital plane is inclined by about 5.1° with respect to the ecliptic plane, whereas the Moon's equatorial plane is tilted by only 1.5°.
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1 answer
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How exactly can one make out the direction of and temperature of winds [closed]

I am trying to make a fictional world, but I want to be as realistic as humanly possible with the winds and climate. So my question is, knowing various parametres, how exactly can I make out what ...
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Cooling the Indian subcontinent using Tibetan Plateau

Apologies if this question may not be up to mark for this stack. I initially asked this on the world building stack but with the lack of replies, I thought I might try my luck here. The main premise ...
3 votes
1 answer
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When will the Earth lose its magnetic field?

Mars lost its magnetic field 4.5 billion years ago according to this article: Mars lost its global magnetic field during the time of this heightened activity. After 500 million years, the Martian ...
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7 votes
1 answer
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Was Earth completely covered in Oceans prior to the onset of plate tectonics?

Following recent develoments in geophysics (Schmidt et al. (2014), and a popular summary), we now know there to be a significant reservoir of water in the mantle-transition of planet Earth, now often ...
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1 answer
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Plain-language summary of why Uranus and Neptune are different than Earth in having large offsets of their dipole field?

This answer to Why is the magnetic axis of Uranus and Neptune off center? in Astronomy SE perplexes me, partly because I can't understand the block quotes and partly because they constrast those ...
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1 answer
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Climate on Venus after it becomes tidally locked

Suppose, Venus becomes tidally locked. Will its dark side cool enough so that the CO2 from atmosphere to precipitate in liquid form to make an ocean?
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How much does the biosphere contribute to Earth's entropy production?

Papers like 1, 2, etc. and the work of Axel Kleidon (e.g. 3) suggest that the the biosphere increases the production of entropy of Earth but I'd like to know if we could quantify this in a simple way. ...
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Calculating Love numbers (tidal deformation) for non-homogeneous planets

I have a question about planetology. I'm not sure if it belongs here, but the astronomy stack exchange seemed a bit odd, too. I would like to enhance my understanding of Love numbers. Love numbers ...
5 votes
2 answers
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What effect does climate change have on the Earth's rotation?

I recently read a blog entry from a leap-second expert explaining that in near term (i.e. last 3 years) the Earth has been spinning ever so slightly faster, delaying the need to insert a leap-second (...
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1 answer
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How do subsurface oceans form under a rocky crust?

New data about Ceres has just been released. Raymond et al. (2020) show the existence of gravity anomalies interpreted as low density pockets of brine under the crust. They show how impacts can ...
3 votes
2 answers
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Now Mars is pulsing 3 times per night in the UV, can anyone explain these waves in simple terms? Do these waves have analogies on Earth?

I link below to questions on another kind of Mars pulse) Phys.org's NASA's Maven observes Martian night sky pulsing in ultraviolet light links to the new paper Imaging of Martian Circulation Patterns ...
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Wasn't Earth a magma ocean before core-mantle differentiation?

I've always thought that the process of planetary accretion was energetic enough to keep the proto-Earth entirely molten, and the subsequent evolution of the planet (the formation of the crust, etc...)...
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Why does the Earth's crust have more aluminum than magnesium while the Sun has more magnesium than aluminum?

Magnesium represents 0.07 % of the composition of the Sun's photosphere while aluminum represents 0.006 %. Therefore, there is much more magnesium than aluminum in the Sun's photosphere. But the same ...
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Geo-Spherical shape of Earth

I know that the best possible approximation of the shape of earth is an oblate sphere. But people also call it as geo-spherical shape of the Earth. What is the meaning of geospherical shape? Does this ...
3 votes
4 answers
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Do we know anything about the nature of Earth's core that hasn't come from magnetic or seismic measurements?

There is much known about Earth's core from painstaking analysis of seismic data, and from detailed magnetic field maps and trends over time. Are there any other measurements that have contributed to ...
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Earth-like conditions on Titan: is it feasible that Titan once had seas and lakes of liquid water?

Given that: 1) Four billion years ago Saturn was hotter and radiated strongly in the infra-red. . . . . . . . . . 2) Like Earth's moon, Titan was then closer to its planet. . . . . . . . . . 3) Like ...
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How do they get "deep lunar mantle" samples?

Phys.org's Study suggests Earth and Moon not identical oxygen twins says They found that the oxygen isotopic composition varied depending on the type of rock tested. This may be due to the degree of ...
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1 answer
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Why is Venus so cracked?

Wired.com's Space Photos of the Week: Perfectly Safe Celestial Coronas includes radar images of the surface of Venus taken from spacecraft in orbit around it. One of them shown below. What causes ...
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How long for tectonic plates to develop from a planetary, molten planetary surface?

On Earth or an Earth-like planet, how long does it take for a molten surface to solidify into planetary crust, and how long does it take for that crust to develop into tectonic plates?
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How could the solar wind cause strange magnetic pulses on Mars at midnight?

24-Feb-2020 NASA News item A Year of Surprising Science From NASA's InSight Mars Mission says: A new understanding of Mars is beginning to emerge, thanks to the first year of NASA's InSight lander ...
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Mars' strange magnetic pulses at midnight; besides the solar wind what are other possible causes?

24-Feb-2020 NASA News item A Year of Surprising Science From NASA's InSight Mars Mission says: A new understanding of Mars is beginning to emerge, thanks to the first year of NASA's InSight lander ...
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6 votes
2 answers
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Why is the mass of atmosphere of Venus so much greater than that of the Earth?

Earth and Venus have a very similar gravity, but the mass of atmosphere on Venus is much greater (according to this wikipedia article 93 times larger). I know that the chemical composition and ...
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4 votes
1 answer
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How do you stop the Australian wildfires?

The Australian fires are the biggest anyone has ever seen and is increasing at a rapid rate causing smog all around the country, approximately 1 billion animals have lost their lives, as of 9 January ...
1 vote
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Will Venus eventually overheat? When it happens, what will happen to it exactly?

Venus is a runaway greenhouse planet, so it won't let any of the heat absorbed from the Sun out by radiation, yet it will still take rays of energy from the Sun. So what will happen to Venus? Will it ...
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Centripetal Force Perfect Ball and Water

I made a question in WolrdBuilding as I was directed to. There a user said that with a perfect ball all water would pool to the equator because of centripetal force. What I do not understand is how ...
4 votes
2 answers
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Which markers could suggest that there was extinct or extant life on Mars?

Researchers who are involved in study of life on Mars are saying that there might be multicellular life present on Mars, today or in the past. Which traces, markers or environments on Mars could ...
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Similarity of seasons on Neptune and Earth [closed]

We all have basic ideas about planets and their seasons..But my question is that why do NEPTUNE and EARTH have similar seasons although their compositions are completely different..On earth Nitrogen ...
1 vote
1 answer
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Effects of Centrifugal Force on Gravity Vectors?

I've been asked this question twice now from our favourite science denying community, and I don't know how to parse it. I can do centrifugal force and gravity given mass, but have never tried to even ...
4 votes
1 answer
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where are the poles of rotation of the tectonic plates located?

Euler's "fixed point" theorem ... can be stated as: The most general displacement of a rigid body over the surface of a sphere can be regarded as a rotation about a suitable axis which passes ...
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Possible and probable source of Curiosity Rover's $\small\sf{CH_4}$ detection on Mars

Past week, NASA announced Curiosity Rover measured 21 ppbv of $\small\sf{CH_4}$ on Mars. This week, NASA's Curiosity Mars rover found a surprising result: the largest amount of methane ever ...
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6 votes
2 answers
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Time standard for IERS Bulletin A

IERS Bulletin A and Bulletin B contains Earth orientation parameters. These include the time difference between UT1 and UTC and pole position. The values for these parameters are listed once per day, ...
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Does anyone know a book/article/research that talks about forest fire prevention?

In my college we have to start our thesis in the third semester, so I'm going to do a research about forest fire and its prevention. However, I'm struggling to find a article that talks about that ...
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Minimum Surface Water for Plate Tectonics?

There is good evidence that the presence of water on a planet's surface is necessary for that planet to have plate tectonics. My question is this: Do we know if there is a minimum amount of surface ...
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Does the global temperature vary daily (hotter and colder days)?

Earth's current average global temperature (i.e. including hot deserts and cold polar caps) is reported be somewhere between 14°C and 16°C (depending on sources and methods). This temperature varies ...
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Would a nuclear explosion over one of the Earth’s magnetic poles momentarily disrupt/weaken the Earth’s magnetic field?

If say the Tsar Bomba had been detonated directly over one of the Earth’s magnetic poles at ground level, would the nuclear electromagnetic pulse generated from that blast have had any momentary ...
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Would the Gaia hypothesis have any practical use?

I recently stumbled upon the Gaia hypothesis, which briefly states that the Earth itself is a living organism. I am wondering: Would this hypothesis have any practical use? Does it make any ...
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What would happen if you hypothetically happened to touch an aurora

I think that if you touch an aurora it will give you radiation damage? But then the solar winds at -90C would freeze you, so speaking metaphorically what would happen?
7 votes
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In an Earth-like planet with no history of carbon-based life forms, would there be limestone?

The extent of my understanding of limestone is about what Wikipedia says at the very top of the page: Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such ...
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Can a cryovolcanic eruption be as powerful as a normal volcanic eruption?

The most powerful volcanic eruption in recorded history was the 1815 eruption of Mount Tambora, an explosion equivalent to 33 billion tons of TNT. Is there any way a cryovolcanic eruption could be as ...
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How long will it take for plate tectonics to shut down and what will the effects be? [duplicate]

As the interior of the earth cools, presumably there will come a time when the temperature gradient is insufficient to maintain the mantle plumes and hence plate tectonics. How long will this take ...