New definition of
POSTED BY: CrevanReaver
UPDATED: Thursday, August 24, 2006 20:56
VIEWED: 3731
PAGE 1 of 2
A committee of the International Astronomical Union has proposed a new draft definition of the term "planet" which would increase the solar system's total well above the current nine by including Ceres, Charon, 2003 UB313 and potentially many other trans-Neptunian objects.
Along with Ceres, Charon and 2003 UB313, a further dozen are likely to join them soon. This proposal does not automatically leave our solar system with 12 planets. Mike Brown, the discoverer of Sedna and 2003 UB313, has claimed that this definition could eventually comprise up to 53 planets in our system alone, with hundreds, or even thousands, not yet discovered.
In its exact wording, the proposed definition is:
Quote:
"A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet."
Under this definition, it's now completely plausible that the Verse's solar system could include hundreds of planets. They are simply very small planets that would have been considered spherical asteroids in the 20th century and in 2002, when Firefly first aired.
NOTIFY: N | REPLY | REPLY WITH QUOTE | PERMALINK | TOP | HOME
Terraforming, here we come!
I wanna go! Chrisisall
NOTIFY: Y | REPLY | REPLY WITH QUOTE | PERMALINK | TOP | HOME
Quote:Except only one planet is defiantly in the habitable zone and no more than three. Doesn't matter how many planets there are in total in our solar system, there’s still only single figures within the habitable zone. Namely Earth (defiantly) Mars (probably) Venus (possibly).
Originally posted by CrevanReaver:
Under this definition, it's now completely plausible that the Verse's solar system could include hundreds of planets. They are simply very small planets that would have been considered asteroids in the 20th century and in 2002, when Firefly first aired.
More insane ramblings by the people who brought you beeeer milkshakes!
No one can see their reflection in running water. It is only in still water that we can see.
NOTIFY: Y | REPLY | REPLY WITH QUOTE | PERMALINK | TOP | HOME
Quote:
Originally posted by citizen:
Except only one planet is defiantly in the habitable zone and no more than three. Doesn't matter how many planets there are in total in our solar system, there’s still only single figures within the habitable zone. Namely Earth (defiantly) Mars (probably) Venus (possibly).
With advanced enough terraforming technology, the habitable zone will not matter. My own theory has always been that they use gigantic orbital mirrors for extra heat and light. The orbital mirrors focus light on each planet, thus little problem with sunlight and distance. So for me, the habitable zone has never been much of an issue. It's that they used the term "planet."
The new definition simply explains how they were able to call them planets - apparently their definition of the word planet was different from ours.
NOTIFY: N | REPLY | REPLY WITH QUOTE | PERMALINK | TOP | HOME
Quote:No a planet still has to reside within the habitable zone for humans to be able to exist on the surface unaided (without enclosures or suits). Orbital mirrors can extend that zone, and a larger hotter star will have a wider zone than ours to begin with, but the habitable zone is far from meaningless.
Originally posted by CrevanReaver:
With advanced enough terraforming technology, the habitable zone will not matter. My own theory has always been that they use gigantic orbital mirrors for extra heat and light. The orbital mirrors focus light on each planet, thus little problem with sunlight and distance. So for me, the habitable zone has never been much of an issue. It's that they used the term "planet."
Orbital Mirrors have been proposed to help terraform Mars, to produce a thicker atmosphere by evaporating polar CO2. These mirrors would be roughly 250km across to magnify sunlight on the ice caps.
Think about it, in order to magnify sunlight on the surface of a planet you'll need a collection surface greater than the planets surface. Orbital mirrors aren't a magic wand that'll make Pluto green; they can probably slightly extend the habitable zone, but not make it irrelevant.
If the Firefly verse had the level of technology to do that they wouldn't have to worry about little things like death, and I think you'll probably find conditions on the rim would be a little less stark.
More insane ramblings by the people who brought you beeeer milkshakes!
No one can see their reflection in running water. It is only in still water that we can see.
NOTIFY: Y | REPLY | REPLY WITH QUOTE | PERMALINK | TOP | HOME
By the way, here are the new categories proposed:
Planet: A round thing orbiting a star. More precisely: "A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet."
Pluton: A planet orbiting beyond Neptune, taking more than 200 Earth years to circle the Sun. So far, it would include Pluto; Pluto's former moon, Charon; and "Xena" (2003 UB313).
Satellite: Anything orbiting a planet, as long as the mutual centre of gravity does not fall outside the planet. Includes several bodies much larger than many planets, such as Jupiter's moon Ganymede (diameter: 5262 kilometres).
Small solar system body: Anything orbiting the Sun that's not a planet or a satellite. Most asteroids and comets would be SSSBs. Currently called minor planets.
Unofficial categories of planet:
Dwarf planet: A planet smaller than Mercury (diameter: 4879 kilometres), which is the smallest uncontested planet. Would include the former asteroid Ceres; Pluto; Charon; and Xena.
Giant planet: Jupiter, Saturn, Uranus, Neptune.
Classical planet: The four giant planets plus the familiar four rocky, terrestrial planets: Mercury, Venus, Earth, Mars.
The intro at the beginning of Serenity could now be:
"Earth-That-Was could no longer sustain our numbers, we were so many. We found a new solar system: dozens of dwarf planets and hundreds of moons -- each one terraformed, a process taking decades, to support human life. To be new Earths."
NOTIFY: N | REPLY | REPLY WITH QUOTE | PERMALINK | TOP | HOME
Quote:I don’t know about that. You might be able to extend the habitable zone out. Clearly the Earth's atmosphere provides a degree of warmth that allows it to exist at the very edge of our sun's habitable zone. However, when nitrogen snow starts falling or the surface is molten, I think you’ve reached the limit of technology.
Originally posted by CrevanReaver:
With advanced enough terraforming technology, the habitable zone will not matter. My own theory has always been that they use gigantic orbital mirrors for extra heat and light. The orbital mirrors focus light on each planet, thus little problem with sunlight and distance. So for me, the habitable zone has never been much of an issue. It's that they used the term "planet."
I see that Citizen has already levied this critism, so you can disregard this.
Nihil est incertius vulgo, nihil obscurius voluntate hominum, nihil fallacius ratione tota comitiorum.
Nothing is more unpredictable than the mob, nothing more obscure than public opinion, nothing more deceptive than the whole political system.
-- Cicero
NOTIFY: Y | REPLY | REPLY WITH QUOTE | PERMALINK | TOP | HOME
I think the key to habitable planet is the balance of atospheric elements. We may end up being in a totally different geological niche, underground, in ocean trenches, whatever, on another planet.
The easiest way to make humans exist on a different temperature level is probably to alter humans. Artic squirrels are extremely similar to humans genetically, and yet can tolerate absurdly low temperatures. When you picture the scale of a terraforming project, human mods may seem more reasonable.
NOTIFY: Y | REPLY | REPLY WITH QUOTE | PERMALINK | TOP | HOME
Quote:The problem with that is we're then creating new species to live on other planets, kinda makes the exercise a little pointless.
Originally posted by dreamtrove:
The easiest way to make humans exist on a different temperature level is probably to alter humans. Artic squirrels are extremely similar to humans genetically, and yet can tolerate absurdly low temperatures. When you picture the scale of a terraforming project, human mods may seem more reasonable.
Also you can't really adapt Humans to be able to sustain temperatures lower than we can now anyway. People can survive in pretty cold climates with minimal technology, and much lower and you are looking at problems where biological life simply can't survive, or at least complex biological life.
The other problem is that people who are modded will be able to live in one place and one place only. Someone designed to live.
The reason why you want to terraform a planet is more than just getting Humans living there, you want to grow crops and raise animals, two things that go along way to producing a viable stand alone colony. That's why you terraform, to produce an off world independent colony. To get the same thing with 'mods' you'd have to engineer an entire eco-system, which I'd hazard a guess could actually be harder than terraforming.
If you're looking for an alternative to terraforming it's called life support technology.
More insane ramblings by the people who brought you beeeer milkshakes!
No one can see their reflection in running water. It is only in still water that we can see.
NOTIFY: Y | REPLY | REPLY WITH QUOTE | PERMALINK | TOP | HOME
Not at all, Citizen
Marsaforming an individual human is easier than terraforming Mars, even if you have to do it a million times. And adaptability would not restrict them from returning to earth necessarily. Arctic squirrels are perfectly capable of living in our environment. Clifford D. Simak tackles this issue in "City". I don't think it's a serious problem.
The trouble with terraforming is how about you going to move a trillion tons of compressed gas? If the planet is close to habitable, would you be exterminating all native life? (it wouldn't be designed for multiple planets like our mod humans.)
NOTIFY: Y | REPLY | REPLY WITH QUOTE | PERMALINK | TOP | HOME