Questions tagged [planetary-science]
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Why are we so quick to proclaim the geological inhospitability of other planets based on extremely minimal information?
Now, I'm not questioning claims that any planet in the Solar System is atmospherically or externally inhospitable, but claims made that other planets have geology that is extremely hostile to ...
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1answer
39 views
Does Earth's magnetic field become stronger when a solar flare hits?
This curiosity arises as follows: when ejecta from a strong solar flare hits Earth, will the Earth somehow counter its impact with a stronger magnetic field.
Or, earth's magnetic field as limited ...
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2answers
199 views
Is there a way to tell the difference between earth andesite from Mars
I'm curios if there is a way to test if this sample might be Martian andesite.
What type of oxygen isotope (or other) test can be done to address this in some way?
As background, any information ...
2
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1answer
72 views
Why would a tidally-locked rocky planet have a first-order spherical harmonic surface temperature distribution?
The new Letter to Nature Absence of a thick atmosphere on the terrestrial exoplanet LHS 3844b (also ArXiv) analyzes the thermal infrared light curve from the system (about 4.5 to 5.5 um). The planet ...
3
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2answers
156 views
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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282 views
Neptune's Internal Heat Source
Unlike its sister planet Uranus,Neptune has a substantial internal heat source which gives rise to a dynamic atmosphere & weather.
Wikipedia says:
As with Uranus, the source of this heating ...
4
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1answer
207 views
Is the boulder on the peak of Tycho Crater the core of the impactor, or is it a random rock?
There's a strikingly visible boulder sitting right at the top of the peak complex in the center of Tycho Crater on the Moon.
Is it just a coincidence that this gigantic, bright rock is sitting dead ...
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4answers
104 views
Is it plausible for a planet that is positioned in the habitable area of a solar system to have little extractable metals?
I am big fan of Asimov's Foundation and I am wondering about the plausibility of some of Foundation's imagined words.
According to this article Terminus was a special world with little metals:
It ...
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1answer
49 views
Does Mars' “Northern ocean” have another name? What about the “Inland Sea”?
The March 15, 2019 Phys.org article A NASA spacecraft may have explored the edges of an early Mars sea in 1997 shows a stylized map of an area on Mars where the Mars Pathfinder landed and uses colors ...
5
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2answers
163 views
How can it be known that Venus does not have plate tectonics?
This answer provides some insight into Venus' surface geology:
Water may be necessary as a lubricant for plate tectonics. Whether or not this is the case, Venus does not have plate tectonics. It ...
3
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1answer
69 views
How do they measure sub-centimeter wave height on a moon of Saturn?
Michael Stevens from V-Sauce has a video called The Mandelbrot Set on a different channel. At 12:56 he says:
There’s a moon of Saturn that has liquid hydrocarbon ...
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1answer
143 views
How did early estimates of a “potato radius” set 1 eV ~ GMμ/R and get 200 to 300 km?
@DavidHammen's answer explains that Goblin has roughly a potato radius and I can't believe I just wrote Goblin and potato in a serious question. That happened.
The linked paper; The Potato Radius: a ...
2
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1answer
88 views
Total rotational angular momentum estimates for Jupiter?
I wrote a quickie answer where I estimate the total rotational angular momentum of Jupiter as about 7E+38 kg m^2/s. However it bothers me because one of the sources gets this number assuming uniform ...
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1answer
66 views
How would you relate the respective solar gravitational pulls of two planets?
I was asked this question:
How much weaker is the gravitational pull of the Sun on Neptune at 30 AU, than it is on Earth at 1 AU?
How would I even begin to determine this?
2
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0answers
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Predicting Temperature Variation on Planets with High Eccentricity or Long Diurnal Periods
Whew! That title was a mouth-full, but accurate I hope. What I'm trying to figure out is a model for calculating the approximate temperature variation for a generally earth-like planet (similar ...
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0answers
155 views
Why does the axial tilt & the rotation speed of Saturn & Jupiter vary so much?
I have seen Jupiter and its 4 largest moons in a telescope, several times. The moons are always aligned in a line. This is fine. Very interesting. But.. in case of Saturn, not only that we can see its ...
4
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1answer
182 views
Wondering about a horseshoe orbit
Since I'm not a physicist, I want to know how that system works.
For instance, if there was a planet, very similar to the Earth, but with two moons, and the moons where in a horseshoe orbit, how does ...
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3answers
651 views
How many things are wrong in this “artist view” of the TRAPPIST-1 system?
There is a this poster on the NASA site
(
that irks me. Of course its an artist's fantasy, but since it is on a NASA site, I see people considering it as scientifically accurate. So, beyond the two ...
5
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1answer
125 views
Is there an established distinction between a geyser and a cryovolcano in solar system bodies?
Is there an established distinction between a geyser and a cryovolcano in the context of cold solar-system bodies such as the moons of Jupiter and Saturn, or Kuiper belt objects (e.g. Pluto)?
Both ...
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177 views
How do astronomers choose their research topic? [closed]
Astronomers don't face much of an ordinary jobs market in their "trade". What does the process look like from choosing a topic for the PhD to doing research in a specific topic?
Let's say that you're ...
