Questions tagged [surface]
Questions about the outermost solid or liquid layer of a celestial body.
44 questions
7 votes
4 answers
2k views
Is the surface of Mars or the Moon mostly (or relatively) homogeneous, unlike the Earth?
The Earth's surface (ignoring the water) is very heterogeneous, with many layers of differing sediment due to the many different eras the Earth has been through. There's also diamond deposits, gold ...
- 187
2 votes
0 answers
101 views
At what point does the rate of rotation of an oblate spheroid hydrostatic body become unstable?
At what point does the rate of rotation make the oblate spheroid unstable? Is this maximum rotation rate a constant or does it depend on the density of the material? Is it at the point where ...
- 89
4 votes
1 answer
680 views
Is surface gravity a constant on rotating hydrostatic bodies regardless of angular velocity and shape?
As a homogenous hydrostatic body rotates, it deforms to an oblate spheroid. It seems intuitive to me that the surface gravity must remain the same regardless of latitude. (otherwise pebbles would roll ...
- 89
4 votes
2 answers
957 views
From which notable Europa's surface features could be possible to observe Jupiter eclipsing the sun?
I'm currently writing a story happening on Jupiter's moon Europa in the distant future and am looking for a location of the settlement where it takes place. As the protagonist likes to observe Jupiter ...
0 votes
0 answers
79 views
Why does the projection-motion of the moon on the earth's surface have the shape of a sinusoid?
Why does the projection-motion of the moon on the earth's surface have the shape of a sinusoid? How does this fit with the tellurium model?
- 993
1 vote
2 answers
243 views
How to calculate the day/permanently dark/night temperatures of different surfaces for exoplanets?
I am trying to calculate the different temperatures (day, night, permanent day/night for tidally locked planets) for different surfaces of exoplanets like land, water, gas, ice. I am using an ...
- 29
1 vote
0 answers
34 views
Surface brightness of transparent vs opaque galaxies
When describing surface brightness of galaxies, I would imagine that in some wavelengths some galaxies are mostly transparent and in other wavelengths some are somewhat opaque (for example galaxies ...
- 121
10 votes
1 answer
355 views
Longest line of sight on Mars
It is said that the slope of Olympus Mons is so gradual that the peak cannot be seen from the plain; it is hidden by the planet's curvature. That provokes questions: How steep is the steepest of the ...
- 426
4 votes
1 answer
108 views
At what point does an astronomical body's surface stop being gas giant-like and start being sun-like?
I've generally seen brown dwarfs depicted as more massive and slightly wider Jupiters in varying colors with banded cloud structures, sometimes hot enough to be visible glowing. I've also seen red ...
2 votes
0 answers
117 views
Surface composition of Mercury?
I've been doing research on the surface composition of Mercury, but it doesn't seem that there are many helpful results online from ArXiv. One article from PNAS describes the composition of Mercury as ...
- 6,892
2 votes
1 answer
160 views
When were the spiders first observed on Mars?
On Mars, there are spider-looking features near the South pole that might be caused by CO2 sublimation. When were these features first observed on the surface of Mars?
- 17.9k
6 votes
2 answers
428 views
What are the dark spots in the "face of Mars" picture?
In this picture of Cydonia by Viking 1 (taken from this article), there are a bunch of black spots scattered everywhere. Are they an artifact of the image or are they an actual feature on the surface ...
- 17.9k
34 votes
2 answers
6k views
Is oxygen really the most abundant element on the surface of the Moon?
I found this infographic that seems to say that oxygen is the most abundant element on the surface of the Moon. Is this really the case? If so, under what form is this oxygen?
- 17.9k
1 vote
0 answers
67 views
Local atmospheric pressure and surface gravity in Jezero crater?
The Jezero crater on Mars is the target location of the American Mars 2020 mission. I can't find any good values on the local air pressure and gravity, though the elevation is around what is ...
- 111
3 votes
1 answer
149 views
Surface of the Sun, or Jupiter, etc [duplicate]
I keep hearing and reading statements that refer to the "surface of the Sun" (how hot the surface of the sun is) or the "surface of Jupiter" (when the Shoemaker comets hit Jupiter)....
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