Steppingstones to nearby stars. The majority of stars are binaries. If rogue planets form from the same gravity-based mechanism, are they mostly binary? Do they eject rogue moons? Wrt gas clouds & 1816-style cooling, the cloud would have to be dense enough to interfere with light from the sun. The solar wind has created our own little bubble to ward them off. Rich --- Quoting Bill Gosper <billgosper@gmail.com>:
On 2017-07-25 17:00, hbaker1 wrote:
FYI -- And we thought that Earth's orbits were getting full of space junk... I can envision 'Star Trek'-like starships ending up like windshield-splatted bugs in picoseconds... https://motherboard.vice.com/en_us/article/mbaw5y/rogue-planets-are-roaming-...
That animation looks wrong. The background galaxy(?) doesn't return to its original position after the planet passes. NeilB has done some serious work here: http://neilbickford.com .
Can someone explain how a collapsing primary can eject a planet?
Julian found traces of the Dancing Stars web page, but the Archive seems to punt Java. That simulation gave a strong but possibly misleading impression that 3-body systems were unstable. (Confinement to 2D massively raises the "triple collision" frequency.) But in a triple or quadruple system, a brown dwarf is likely first to leave.
Shouldn't we also worry about dust clouds? Judging by the "summer" of 1816, an interplanetary cloudy spell could kill almost everything. --rwg
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature23276.html
Planet formation theories predict that some planets may be ejected from their parent systems as result of dynamical interactions and other processes. Unbound planets can also be formed through gravitational collapse, in a way similar to that in which stars form. A handful of free-floating planetary-mass objects have been discovered by infrared surveys of young stellar clusters and star-forming regions as well as wide-field surveys, but these studies are incomplete for objects below five Jupiter masses.
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