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AndromedaRXJ
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How feasible is such a planet? Can the planet still be dense enough to be rocky and not gaseous?
jim mcnamara said:Or did you mean a same mass planet with much bigger continents? Other than increasing very arid land area and decreasing open water area, it would "work". Assuming everything else is Earthlike - whatever that is.
mfb said:Surface gravity is proportional to mass/radius2, surface area is proportional to radius2. Double the surface are and you need mass to increase by a factor 4, but the volume increases by a factor 8. That means half the density. Difficult to do with rock. An ocean world would work. A rocky core, then a thick layer of (high pressure) ice and a global ocean. Not very Earth-like, however.
~200 km before you reach the ice, even more before you reach rock, islands or continents don't work. If some intelligence is involved then you can make floating islands of arbitrary size.AndromedaRXJ said:How deep would the ocean be compared to real-life Earth? And is it downright impossible to have continents, or just very unlikely? What about a few islands or one small continent?
I'm not sure if that would work naturally, but artificially: Sure.Torbert said:Couldn't a solar system form in a low iron space? Silicon and carbon are the main ingredients of many an asteroid. Form the planets without heavy metals and the mass of a larger planet could equal half the density of the smaller planets with iron cores.
Tghu Verd said:I always come back to the main response that it's sci-fi and most readers won't know about the mechanics of mass vs. surface area vs. gravity, they'll just take it as written.
Vanadium 50 said:As an example, take Silverberg's Majipoor. It's much larger than Earth
Dr Wu said:Competing pet theories could be forwarded, argued over, etc. . . a case where mystery and doubt could actually add to the novel's believability, in fact. Not having all the answers has always been part of the human condition, after all. That being so, there's no reason why the future - even an advanced spacefaring one - should be exempt from this shortfall. Whatever else the future holds, you can be darn sure puzzlement will have a place in it.
mfb said:Artificial planet-scale magnetic fields are no problem in science fiction as long as something (can be robots) takes care of maintenance.
The atmosphere on this planet would likely be thicker and more dense compared to Earth's atmosphere. This is because the larger surface area would allow for more gases to be present and the same surface gravity would not be able to hold them down as tightly as it does on Earth.
It is difficult to determine the exact ratio of land to water on this type of planet without knowing more about its composition and geological history. However, it is possible that there could be more land due to the larger surface area, which would allow for more landmasses to form.
The day and night cycle on this planet would likely be longer compared to Earth's 24-hour cycle. This is because the larger surface area would mean that the planet would rotate more slowly on its axis.
It is possible that this planet could support human life, depending on its distance from its parent star and the presence of a suitable atmosphere. However, other factors such as temperature, water availability, and the composition of the planet's surface would also play a role in determining its habitability.
The flora and fauna on this planet would likely have evolved differently due to the larger surface area and potentially different environmental conditions. There may be a greater diversity of species, and some may have adapted to the longer day and night cycle or the thicker atmosphere.