New answers tagged

2

Scientists (and science fiction writers) have speculated about the possbilities of life under the surfaces or on the surfaces of large moons in our solar system or large exomoons of large exoplanets in other star systems. So a good place to find any limits on the possible properties of moons that can have magnetic fields is a scientific discussion of the ...


1

Even if the moon weighed twice as much as our planet, given a rotation of 27 days it wouldn't have a major geodynamo, which is proportional to mass, rotation speed and electromagnetic constituents. It has to have higher rotation speed and a lot of iron at the core. The moon's rotation is nearly zero, or once every 27 days compared to our 24 hours. In 2010, a ...


4

Short Answer: It might be possible to have a chain of as many as twelve objects, but that depends on how many of the objects in that chain actually have stable orbits around other objects in the chain. Long Answer: My first guess would be something like: Virgo Supercluster of galaxies > the gravitational center of the Local Group of Galaxies > The ...


11

Certainly 4 (perhaps 5): The longest certainly-known chain is "3": Sun-Earth-Moon. Rhea (a moon of Saturn) has been observed to have a ring of orbiting material: That gives Sun-Saturn-Rhea-Ring for four levels (including unresolved dust) Looking further afield: DH Tauri and DI Tauri are a binary pair of similarly sized T-Tauri stars (both small ...


3

Wikipeida (quoting Icarus ) gives $$\frac{15}{8}\frac{mA^4}{Mr^3}$$ Where $m$ and $M$ are the masses of the moon and planet, respectively; $r$ is the orbit radius of the moon and $A$ is the radius of the planet. For Earth this is a little less than a metre. Systems with multiple moons (or moon and sun, like on Earth) will have multiple bulges which can add ...


2

No, this can never be stable over long periods of time. First of all, drag from the air in from of the moon would cause it to quickly deorbit and plunge into the gas giant. No amount of wind will be able to keep the moon up in the air. A gas giant's orbital speed near the cloud tops will be over 30 km/s (See the orbital velocity of Metis, Jupiter's innermost ...


Top 50 recent answers are included