Questions tagged [planetary-science]
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1answer
39 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
125 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 ...
4
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1answer
58 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 ...
3
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1answer
83 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 ...
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1answer
58 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
44 views
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 ...
2
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0answers
131 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 ...
5
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1answer
168 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 ...
4
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2answers
170 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
99 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 ...
-3
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1answer
154 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 ...
