DocM Posted March 1, 2011 Share Posted March 1, 2011 Steppenwolf planet: a planet with no star, usually ejected by a close pass by another body etc. Imagine the evolutionary possibilities.... Paper.... Synopsis:The Steppenwolf: A proposal for a habitable planet in interstellar space Dorian S. Abbot, Eric R. Switzer (Submitted on 5 Feb 2011) Rogue planets have been ejected from their planetary system. We investigate the possibility that a rogue planet could maintain a liquid ocean under layers of thermally-insulating water ice and frozen atmosphere as a result of geothermal heat flux. We find that a rogue planet of Earth-like composition and age could maintain a subglacial liquid ocean if it were ~3.5 times more massive than Earth. If a rogue planet had about ten times higher water mass fraction or a thick cryo- atmospheric layer, it would need to be only ~0.3 times the mass of Earth to maintain a liquid ocean. Such a planet could be detected from reflected solar radiation and its thermal emission could be characterized in the far-IR if it passed within O(1000) AU of Earth. Link to comment Share on other sites More sharing options...
vincent Posted March 2, 2011 Share Posted March 2, 2011 Would be kind of hard for life to get a foothold if it's hurdling aimlessly though space, i think it might stabilize or have a better chance if said planet can be gravitationally captured by another star..then again im no astrobiologist Link to comment Share on other sites More sharing options...
DocM Posted March 2, 2011 Author Share Posted March 2, 2011 You forget the numerous lifeforms here on Earth that depend on chemosynthesis instead of photosynthesis, even secondarily as predators. Life does not live by light alone. Hell, some animals don't even use iron in their blood and some critters live in the midst of solid glacial ice at subzero temps. Others live in boiling acid volcanic springs. There are even subterranian bacteria that live indirectly off of radiation. Link to comment Share on other sites More sharing options...
vincent Posted March 2, 2011 Share Posted March 2, 2011 You forget the numerous lifeforms here on Earth that depend on chemosynthesis instead of photosynthesis, even secondarily as predators. Life does not live by light alone. Hell, some animals don't even use iron in their blood and some critters live in the midst of solid glacial ice at subzero temps. Others live in boiling acid volcanic springs. There are even subterranian bacteria that live indirectly off of radiation. I understand the climate differences in which life here can thrive in, what im referring to is the physics of steppenwolf planets, Imagine if earth's roation were to suddenly stop, also imagine if the sun were to suddenly dissappear, now further imagine that earth were to get hit by another object that would hurdle us into break neck speeds into interstellar or perhaps intergalactic space. Not saying life is impossible on Steppenwolfs but a bit more difficult imo at least. Then again, like i said im not an astrobioloigst Link to comment Share on other sites More sharing options...
DocM Posted March 2, 2011 Author Share Posted March 2, 2011 Well, it's not necessary to be hit to be ejected from a stellar orbit - the close pass of a brown dwarf etc through the systen could do it too. It's also very unlikely that rotation would be stopped - it more likely would be slowed or even sped up a bit. As long as the radioactive decay in the core was enough to keep most of the planet above freezing lifeforms would survive. It's even possible for the surface to stay thawed, but animals that depended on photosynthesis and their predators would have a tough time. OTOH a very advanced civilization that already had ebolved past fossil fuels into a geothermal, fusion or some other such non-solar power system, and who also used advanced food production (hydroponics, engineered "meats" etc) might be ae to survive, especially in underground shelters warmed passively by geothermal heat - advanced Morlocks, if you will. Link to comment Share on other sites More sharing options...
neoadorable Posted March 3, 2011 Share Posted March 3, 2011 wow...starless planets...it makes sense that there's tons of them, but they must be quite dark, cold places... Link to comment Share on other sites More sharing options...
carmatic Posted March 3, 2011 Share Posted March 3, 2011 wow...starless planets...it makes sense that there's tons of them, but they must be quite dark, cold places... not when theres volcanic activity on the planet itself and life forms would then live off the volcanic heat rather than the light from a star that the planet orbits Link to comment Share on other sites More sharing options...
neoadorable Posted March 3, 2011 Share Posted March 3, 2011 true, but by our standards they'd be literally dark, i.e very little starlight. galactic aura yes, but no sunshine per se. Link to comment Share on other sites More sharing options...
Hum Posted March 6, 2011 Share Posted March 6, 2011 Oh screw in a few thousand lightbulbs and you'd be good to go. :laugh: More seriously, would lone planets have gravity ? Maybe low gravity ... ? Link to comment Share on other sites More sharing options...
neoadorable Posted March 6, 2011 Share Posted March 6, 2011 they should, gravity comes from mass, planetary mass can exist irrespective of stars. Link to comment Share on other sites More sharing options...
carmatic Posted March 6, 2011 Share Posted March 6, 2011 Oh screw in a few thousand lightbulbs and you'd be good to go. :laugh: More seriously, would lone planets have gravity ? Maybe low gravity ... ? when you think of 'gravity' do you think of orbits, hence if there is no orbit there is no gravity? Link to comment Share on other sites More sharing options...
Hum Posted March 6, 2011 Share Posted March 6, 2011 I thought a planet had to spin on its axis, to at least provide a magnetic field against radiation, as well as regulate 'gravity'. Would a loose planet spin ? Link to comment Share on other sites More sharing options...
rob.derosa Posted March 6, 2011 Share Posted March 6, 2011 Detectable if it comes within 1000 AU of Earth.. so either there has to be literally billions of these guys per cubic parsec, or we aren't ever going to detect one...! Link to comment Share on other sites More sharing options...
Stetson Posted March 6, 2011 Share Posted March 6, 2011 Oh screw in a few thousand lightbulbs and you'd be good to go. :laugh: More seriously, would lone planets have gravity ? Maybe low gravity ... ? If the earth were a lone planet it'd have the same gravity it does now. Also no reason that it couldn't spin, our spin doesn't really have much to do with our orbit. Link to comment Share on other sites More sharing options...
rob.derosa Posted March 6, 2011 Share Posted March 6, 2011 I thought a planet had to spin on its axis, to at least provide a magnetic field against radiation, as well as regulate 'gravity'. Would a loose planet spin ? Once it starts spinning (caused by angular momentum conservation during the initial collapse of the proto-planetary cloud) it takes a long time to lose this angular momentum through tidal dissipation. Link to comment Share on other sites More sharing options...
neoadorable Posted March 7, 2011 Share Posted March 7, 2011 gravity is only related to mass i believe, magnetism comes from density and the composition of the core, not from spin, but correct me if i'm wrong. Link to comment Share on other sites More sharing options...
Nihilus Posted March 7, 2011 Share Posted March 7, 2011 gravity is only related to mass i believe, magnetism comes from density and the composition of the core, not from spin, but correct me if i'm wrong. No no, you're right. Gravity is due to mass, magnetism is down to having a molten metal core and the core is kept molten due to spin. If I'm not mistaken if a planet lost it's spin, the core would eventually solidify. Losing geothermal energy, and causing it's magnetic field to collapse, killing everything on the planets surface. Fortunately a planet doesn't need a star to spin :) Link to comment Share on other sites More sharing options...
neoadorable Posted March 7, 2011 Share Posted March 7, 2011 yes, that's what i thought, but i still don't understand why places like Mars and Venus have almost no magnetic field, they're still spinning just fine! Link to comment Share on other sites More sharing options...
Teebor Posted March 7, 2011 Share Posted March 7, 2011 yes, that's what i thought, but i still don't understand why places like Mars and Venus have almost no magnetic field, they're still spinning just fine! From what I understand, and that is limited, but it is also limited by the fact that I don't think anyone really knows why the earth has a magnetic field. It is something to do with the molten metals in the earth outer core which have been subject to a charge (possibly from the sun many millions of years ago), this then constantly moving mass pretty much then keeps building up the magnetic field until it reaches its maximum. Ultimately as someone already said though if the core cools down enough and solidifies that movement is lost and so the field collapses. Circulation of a liquid metal alone would not generate a magnetic field. Circulation alone would just get the proton and electrons moving in the same direction. Since these particles have opposite charges, they would create opposing magnetic fields if they are moving in the same direction. Therefore, their fields would cancel each other out. In order to get a circulating liquid metal to generate a magnetic field, you need an initial magnetic field to start the proton and electrons moving in opposite directions as the liquid circulates. This creates an electrical current that will then strengthen the initial field which will then strengthen the current, etc. until we reach the maximum strengths for each that is allowed by the conditions. This is not a chicken or egg problem. The fact of the matter is that you must have both circulation and a magnetic field in order start the current. So my guess would be they are too far away from the Sun to have been affected in this way as much, different internal composition, and many other factors Link to comment Share on other sites More sharing options...
Nihilus Posted March 7, 2011 Share Posted March 7, 2011 yes, that's what i thought, but i still don't understand why places like Mars and Venus have almost no magnetic field, they're still spinning just fine! Non-metal cores? I think core-composition, mass and speed of rotation play a large factor. But obviously a non-metal core isn't going to have any electrical currents running around down there xD From what I understand, and that is limited, but it is also limited by the fact that I don't think anyone really knows why the earth has a magnetic field. It is something to do with the molten metals in the earth outer core which have been subject to a charge (possibly from the sun many millions of years ago), this then constantly moving mass pretty much then keeps building up the magnetic field until it reaches its maximum. Ultimately as someone already said though if the core cools down enough and solidifies that movement is lost and so the field collapses. So my guess would be they are too far away from the Sun to have been affected in this way as much, different internal composition, and many other factors I don't think anyone knows the "exact" mechanics of it. However I'm pretty sure it's known to be due to having a liquid metal core, in which the liquid circulates and generates a slight electric current. Like building a rather big electromagnetic. Link to comment Share on other sites More sharing options...
neoadorable Posted March 8, 2011 Share Posted March 8, 2011 thanks for the explanations. it shouldn't be distance from the sun, it has to be composition. i mean Venus is closer to the old gasbag than we are, and she's got very little in the way of a magnetic field. Link to comment Share on other sites More sharing options...
DocM Posted March 9, 2011 Author Share Posted March 9, 2011 Magnetic fields in rocky planets arise from a rotating solid iron/nickle (80% of the total) inner core about the size of the moon and a molten outer core, both spinning faster than the rest of the planet. Fully solidified core = no or little magnetic field. In the case of a gas giant like Jupiter it's a spinning core of hydrogen in its metallic phase. That can form only under enormous pressures. Residual heat is enough to keep an iron/nickle core liquid for a while, but not as long as Earths has. The source of the extra heat is the radioactive decay of trace isotopes, mostly potassium-40 but also uranium. Link to comment Share on other sites More sharing options...
neoadorable Posted March 9, 2011 Share Posted March 9, 2011 cool, thanks for clarifying that Doc. so in practical terms a compass would be useless on Mars or Venus, right? thank goodness for GPS i suppose... Link to comment Share on other sites More sharing options...
DocM Posted March 9, 2011 Author Share Posted March 9, 2011 The core of Venus is almost solidified and that of Mars is almost certainly so. As such, long term habitation on Mars will require a local artificial magnetosphere or heavy shielding. The early development has been done for an artificial magnetosphere for spacecraft, but in an atmosphere its more difficult. Yes kiddies, spacecraft could soon have shields. Link to comment Share on other sites More sharing options...
neoadorable Posted March 11, 2011 Share Posted March 11, 2011 those will be cool, less need to worry about debris and random meteor showers that don't show up on radar. will be handy when we send light-speed ships to one of those roving steppenwolf planets :whistle: Link to comment Share on other sites More sharing options...
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