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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1answer
389 views

What “g” would be needed to keep helium on Earth?

I know that helium is a very light and rare gas on Earth because Earths gravity is not strong enough to keep it. Instead, helium and hydrogen are rising through the atmosphere and escape into outer ...
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2answers
497 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 ...
6
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2answers
399 views

Are old geophysics textbooks useful?

I have had much success with old textbooks in mathematics. Generally, for any branch of mathematics that I (as a non-mathematician) would like to learn or re-learn, I can buy a classic textbook from ...
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3answers
365 views

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 ...
6
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1answer
278 views

What are Ordovican trace fossils, and what do they look like?

There are some unusual structures in recent images from the Mars Curiosity Rover's MAHLI (Mars Hand Lens Imager) shown in the Space.com article Curiosity Rover Spots Weird Tube-Like Structures on Mars....
6
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2answers
71 views

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, ...
6
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3answers
271 views

What are the conditions for an ionosphere to form?

I already asked this on Astronomy SE but did not receive any answer so far: What are the prerequisites for an ionosphere to form? For example, can a planet without any atmosphere have an ionosphere? ...
6
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1answer
886 views

Differences between hydrothermal vents on Earth and Europa

Hydrothermal vents are common in areas subject to volcanic activity at the bottom of Earth's oceans. Meanwhile, hydrothermal vents are believed to exist on Jupiter's moon Europa and maybe in other ...
6
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1answer
73 views

Mars maar craters explosive style formation gravitational effect

"Maars usually form when magma rises within a fissure and interacts with groundwater. If groundwater ceases to interact with magma at times during the eruption, continued magma ascent to the surface ...
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6answers
2k views

Would life on Earth survive without the Sun?

Would life on Earth survive if Sun wasn't there? My teacher told me that there are chances that it would but there would be a lack of gases and chemicals and photosynthesis that occurs with light at ...
5
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2answers
128 views

How would a world entirely covered in oceans get the nutrients to support life?

On earth nutrients flow from the land to the ocean. Life on oceans need those nutrients to trive. I was trying to think how an ocean world might support life if there was no land to provide the ...
5
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1answer
168 views

Why does helium-3 stay in the moon and not escape from it?

So the moon is full of helium-3. Since it's a gas in the moon's vacuum... Why doesn't it escape?
5
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1answer
732 views

Is there a time difference between two points at the same longitude but at different latitudes?

Assume we have two cities A and B both at the same longitude (say $45^{0}$ E) but at different latitudes say $8^{0}$N and $90^{0}$ N. Can we get a time difference between these two cities. I raised ...
5
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1answer
174 views

What would a planet's sky look like with different chemical compositions, such as low nitrogen, high methane etc?

What are the processes, chemicals and particles involved in creating colour in a planet's sky? Could you give some examples of sky colour processes different from what happens on Earth?
5
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2answers
173 views

What is the CI chondrite concentration of REEs/rare metals, in ppm/grams per ton?

I am researching the abundances of rare earth elements and rare metals in meteorite samples, because I want to investigate the notion that asteroids represent abundant stocks of rare resources. The ...
5
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1answer
266 views

What are the relative contributions of planets to the Milankovitch Cycles?

When reading about the Milankovitch cycles here, it says: If the Earth were the only planet orbiting our Sun, the eccentricity of its orbit would not perceptibly vary even over a period of a ...
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3answers
640 views

What natural phenomena increase stratospheric ozone?

Most of us know that the ozone layer gets depleted due to green house gasses and other factors. Which made me wonder, is there any natural phenomenon that causes an increase in ozone?
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1answer
175 views

How can scientists measure chemical composition on other planets?

How can scientists measure chemical composition (oxygen, nitrogen etc) and temperature on other planets without being there?
4
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1answer
95 views

doubt about the 'white spaces' in the maps from satellite

I have a doubt about the 'white spaces' in the maps from satellite. For example, for the atlantic areas I have plotted AOD and appear many areas where sistematically do not have any data (white spaces)...
4
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1answer
211 views

Source of sub-surface ringwoodite water

I was reading about the discovery of vast amounts of water locked up in ringwoodite (see here). The authors of the study seem to suggest that previous ideas, involving water deposits being delivered ...
4
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1answer
94 views

Are oceans a major factor in creating high winds on a planet?

This question only pertains to oceans of water and how much they account for the process of creating high winds on a planet with any type of atmosphere.
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0answers
61 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 ...
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0answers
140 views

Did Theia collide directly with proto-Earth?

I was learning about the formation of Earth on Kahn Academy where it was mentioned that a protoplanet named Theia had a glancing impact with the earth and formed the moon. It seems like there is also ...
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3answers
519 views

Eclipse, Hurricanes, Earthquake…Related Events?

Forgive my ignorance, I'm out of my depth. My wife has pointed to the upsurge climate and geological activity post Eclipse. My immediate response, at least inwardly, was to reject her suspicion. ...
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2answers
183 views

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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2answers
94 views

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?
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1answer
205 views

How does water still exist on the Earth?

Almost all the theories that explain the origin of Earth says, it was way hot back then. That means It was in a lava state in its early days. Then gradually cooled down to the current state. If ...
3
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2answers
514 views

How long it takes to cool a planet?

Suppose a planet like Earth or Venus is totally isolated from sunlight. How quick would it cool down? On Earth it seems to me that the air temperature drops significantly even during a night. Does it ...
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1answer
6k views

What time and date is the sun directly overhead a given place on Earth?

In different regions, the sun is directly overhead at different times of the year. When do these event happen?
3
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1answer
105 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 ...
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0answers
274 views

Puzzle using relative dating principles

This isn't directly looking at a real life ecological example kind of thing, but it requires knowledge of relative dating, so I thought I would come here. Here is what was told: -"Worms" (curved ...
2
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2answers
119 views

How to graph gravity as a function of depth, given radius and density?

I need to do this for a planet that has uniform density, and a planet that has two layers. For the first part, I was given that the density was 550 kg/m³, so I made one column in an Excel spreadsheet ...
2
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2answers
389 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 ...
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2answers
117 views

Terrestrial Day vs. Venusian Day: Why the Huge Time Difference?

The diameters of Venus (7,520.8 miles) and Earth (7,917.5 miles) are comparable, but the disparity of the length of the day for each planet - as expressed in terrestrial hours - is enormous; a day on ...
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1answer
32 views

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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2answers
83 views

Why is “at least a small tilt” between rotation and magnetic axis required by models of magnetic field formation?

I saw something I don't understand in the Gizmodo article Cassini's First Grand Finale Images Are Stunning—But What Are We Really Looking At?. In a quote of Caltech Professor of Planetary Science ...
2
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1answer
334 views

How will axial precession affect the weather in the northern hemisphere (UK latitudes)?

Unless there's a twin star to our sun in which case axial precession might be an illusion the Earth's wobble won't effect the total amount of energy received from the sun as is expected from increased ...
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1answer
172 views

Is the majority of Earth not unique?

Realize that comparing planets is hard, but is Earth really that unique? More to the point, if everything say 20-km below sea-level up into the exosphere disappeared (and the moon too) - what would ...
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0answers
32 views

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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0answers
64 views

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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0answers
37 views

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 ...
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0answers
327 views

What is a weather system?

I heard on Star Talk Radio that Jupiter has weather systems larger than Earth so I was just curious to know what the definition of a weather system is exactly.
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42 views

what is the role of absence of land in south atlantic ocean cyclone formation [duplicate]

sir do absence of land plays role in formation of cyclone in south Atlantic ocean and east pacific ocean
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3answers
509 views

Which physical parameters can we actually measure to confirm the existence of the Greenhouse Effect (GHE)? [closed]

The theory of a GHE in a planetary atmosphere is rather well known. Many claim it is no longer a theory but actually proven as a fact. However I have been reading a lot of things Richard Feynman said ...
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1answer
46 views

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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1answer
48 views

Stars twinkling [closed]

What is the science behind the vigorous glow of stars ? Since 2 days I was observing one of the stars in blue and red colour I just want to know what is the speciality of that star?
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2answers
199 views

Is there another explanation than an asteroid/volcano for the extinction event on Earth millions of years ago?

This idea keeps on appearing in my mind, once in a million years the Sun's gravity will pull Earth near and eliminate every living in the earth due to the increased heat, and in another million years ...