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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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According to the official and latest result, Earth's mass is 5.972 x 10^24. How is this answer obtained and what is the formula?

The formula to get the answer of the earth's mass which is 5.972 x 10^24.
3 votes
1 answer
85 views

Why hasn't all the water on earth evaporated and been frozen at the poles?

It seems like over a long enough time scale, if the surface temperature of a planet varies between perennially below freezing and occasionally above freezing, that all of the water on the planet would ...
7 votes
1 answer
111 views

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 ...
1 vote
2 answers
628 views

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 ...
1 vote
0 answers
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Wind patterns on a tidally locked planet (one side always faces the sun)

I'm moving this question from Worldbuilding StackExchange (Link). I know it's not strictly about Earth, but I'm hoping it will still be accepted here since it's related to meteorology. Here we go: My ...
3 votes
1 answer
116 views

Pre-Phanerozoic CO2 levels and pluricell life influence in C Earth's cycle

This graph presents an estimate of Phanerozoic CO2 levels on Earth. From the onset of the graph, it appears that CO2 levels are rising. However, I've come across papers, such as this one, suggesting ...
9 votes
3 answers
721 views

How bad is geo-engineering?

It is just curiosity that forced me to ask this question. At some point in time, if we can't control global $\sf{CO_2}$ emissions, temperature will increase until a tipping point and it will be a ...
22 votes
2 answers
979 views

Is there geological evidence that the moon once collided with the Earth?

I've seen models in astronomy that show how the Earth-Moon system must have come together after a collision. However, I have not heard whether there is any actual physical evidence on Earth that ...
3 votes
2 answers
865 views

Was there once a glacier over Starcke national park in Queensland Australia?

I was randomly exploring Google Earth when I came across some sort of rock formation in northern Australia. The location of the rock formation with respect to Australia is shown below. It is in or ...
2 votes
1 answer
72 views

Can a tectonic plate subduct under one plate while another plate subducts under it along the same boundary?

At a triple junction plate boundary there are three tectonic plates meeting. We have plenty of examples of these boundaries on Earth, notably the Afar Triple Junction, Mendocino Triple Junction, and ...
3 votes
1 answer
294 views

Why are storms relatively short on Earth?

From reading articles and the such it is clear that other planets such as Jupiter have storms that lasts months over months. However on Earth, storms last much shorter. In fact, the longest storm was ...
2 votes
1 answer
44 views

Displacement-Length scaling relationship on extraterrestrial faults

Faults on Earth share a similar displacement/length ratio of around 0.03 which scales from very small faults to very large faults. Would this apply to faults on other planets and if so, are there any ...
1 vote
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Planetary surface temperature from first principles

How can you calculate planetary surface temperatures from first principles? The obvious application is for Earth, with a surface temperature of $288$K. I want a calculation with no fudge factors (i.e.,...
4 votes
1 answer
106 views

Why was quartz not a major product of the Lunar Magma Ocean?

Fractional crystallisation generally makes magma more silicic. Why was a substantial quartz layer not a product of the stratification of the Lunar mantle?
11 votes
2 answers
252 views

What oxidised the soil on Mars?

What exactly was it in the ancient Martian atmosphere that made it red? Was it water, molecular oxygen or something else?
4 votes
1 answer
61 views

How to estimate altitude of tropopause of other planets?

Is it possible to come up with a formula to estimate the height of the tropopause and the upper layer lapse rate only based on atmospheric composition and other atmospheric parameters (not relying on ...
1 vote
0 answers
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Can the planetary alignment actually affect earthquakes? [duplicate]

We've been hearing a lot these past few days about planes alignments and how it would affect seismology. How scientifically true is that?
11 votes
1 answer
838 views

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 ...
2 votes
0 answers
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Moist adiabatic lapse rate

I asked this question in the Physics SE but it still lies unanswered. Hopefully Earth Science SE is more knowledgeable in the matter. Wikipedia gives the following equation to calculate the moist ...
13 votes
6 answers
2k views

Are there any photographs of mountains without significant erosion (on Earth or otherwise)

I'm curious about how mountains on an airless world such as the Moon would look if you were standing on the surface and looking at them. There are plenty of artists' impressions, of course, but I'm ...
11 votes
5 answers
6k views

Carbon dioxide on Mars, Venus and Earth

Earth's atmosphere is 0.038% carbon dioxide. Mars's atmosphere is 95.3% carbon dioxide. Venus's atmosphere is 96.5% carbon dioxide. If Earth's climate is controlled by CO2, then why is Mars so cold ...
8 votes
2 answers
518 views

Is it possible for tsunamis to occur on deep water planets?

Assume a water planet with an ocean depth of about 200-500 km. Would a very strong ground-quake happening at the very bottom of the planet's ocean floor be able to cause a large tsunami to rise up to ...
3 votes
1 answer
136 views

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?
2 votes
0 answers
26 views

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 ...
6 votes
1 answer
101 views

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 ...
1 vote
1 answer
438 views

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?
4 votes
1 answer
1k views

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?...
2 votes
0 answers
38 views

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 ...
1 vote
1 answer
79 views

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 ...
3 votes
2 answers
238 views

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 ...
5 votes
0 answers
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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 ...
5 votes
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99 views

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 ...
6 votes
1 answer
688 views

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 ...
2 votes
1 answer
289 views

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°.
4 votes
1 answer
1k views

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 ...
2 votes
1 answer
86 views

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 ...
3 votes
1 answer
609 views

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 ...
14 votes
2 answers
3k views

Earth's ocean basins

Was Earth's sea-floor always carved with the numerous geological features that we see today, or was it at some point flat and boring as Mars is today?
1 vote
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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 ...
35 votes
1 answer
6k views

What factors determine the number of Hadley cells for a planet?

We know (think?) that Earth has three Hadley cells per hemisphere, but from observing gas giants such as Jupiter, we see that they have many more cells. According to a link from a comment in this ...
8 votes
0 answers
196 views

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...)...
5 votes
1 answer
183 views

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 ...
7 votes
1 answer
149 views

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 ...
2 votes
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 ...
3 votes
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?
5 votes
0 answers
153 views

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. ...
6 votes
1 answer
270 views

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 ...
15 votes
5 answers
3k views

Is Earth an organism?

According to Wikipedia, "all known types of organism are capable of some degree of response to stimuli, reproduction, growth and development and self-regulation via homeostasis." Further, watching a ...
20 votes
4 answers
17k views

Will the Earth ever stop rotating?

It is well known that the Earth's rotation is slowing down and that millions of years ago there was a point in time where there was only a mere 20 hours in a day on Earth. My question is in two parts....
16 votes
1 answer
519 views

How much silicon is in the Earth's core, and how did it get there?

With some informal conversation with a peer of mine, he had suggested that there is evidence (which he couldn't find,but had remembered reading) that there was Silicon in the Earth's core. I referred ...