12

To answer this, one really has to understand how the geometric and bond albedos are defined. Let's start with the bond albedo since its simpler. Bond Albedo The Bond Albedo is just the fraction of energy hitting a surface that gets reflected. To simplify the process, let's say I shoot 100 photons of all the same energy at Enceladus. Of those 100 photons ...


9

From your first link, the definition is: "The circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.[1][2][3][4][5] The bounds of the CHZ are based on Earth's position in the Solar System and the amount of ...


7

This puzzle is something called the Mimas paradox. The two bodies are nearly twins, but Mimas is substantially less active than Enceladus. There are currently several proposed solutions: Mimas cooled quickly, before it entered its resonance with Tethys (which contributes to tidal heating, just as Dione does for Enceladus). A "hot start" from rapid ...


4

Limitations to life via osmosis is mostly a modern limitation. Modern in the 'geological era'-sense. Why osmosis can affect life negatively is, very roughly, when concentration gradients past a bi-lipid cell wall becomes large enough, the transport proteins in the cell wall can't keep up to fight the chemical gradient, and the cell looses its water, thus ...


4

I actually found this very useful article, which seems to answer the question: https://phys.org/news/2021-05-salty-enceladus-ocean-ice.html It suggests that the liquid water in the Enceladus ocean has between 10 and 30 grams of salt per kg of water. This is comparable with, or slightly less than, the Earth's oceans (with an average of 35g/kg) This is based ...


3

A geyser is a water volcano, they are familiar and fairly common on Earth. By analogy, a water volcano on other planets can also be called a geyser, although the mechanism may be rather different. Geysers on Earth are caused by heating of sub-surface water by magma chambers. On Enceladus, there is no magma. The energy of the volcanos of Enceladus is ...


3

Question: I would know why the words "geysers" and "jets" would be used interchangeably. Is this because it hasn't been confirmed yet what they are, and the authors don't wish to show favoritism by choosing one or the other, or are they synonymous and can always be used interchangeably, or is there some other reason ? A jet is a generic ...


3

We start by calculating the moon Enceladus surface escape velocity $v_e$ as $$v_e=\sqrt{\frac{2GM}{r}}$$ where $G = 6.674×10^{-11}m^3kg^{-1}s^{-2}$ is the universal gravitational constant, $M=1.08×10^{20}kg$ is the moon mass, and $r=2.52×10^5m$ is the radius of the moon. Evaluation of the above equation gives us an escape velocity of about $239m/s$. Perry et ...


2

You don't need to do it that complicated. The sunlight's spectrum is the same everywhere in the solar system. And in order to get the light intensity, you can simply apply the inverse square law that intensity drops to 1/4 if you double the distance to the sun - like you did for getting the irradiance. The spectral sensitivity of the human eye is also the ...


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