08-06-2014, 05:13 AM
(This post was last modified: 08-07-2014, 04:30 AM by iancampbell.)
(08-05-2014, 10:57 PM)kch49er Wrote: If a Venus-analouge spun faster but still retrograde(perhaps whatever slowed its rotation was bigger and caused it to stop spinning and staart going the other way) Woul this have had any effect on Venusian life? Would it cause the magneitc north and south to flip? Possibly confusing migratory lifeforms that navigated via it?
Can't see it. Planetary magnetic fields periodically switch polarity anyway - at least that of Earth does. The reason is unknown, but probably connected with the chaotic motion of the molten iron of the core.
As a matter of fact, some people think we are at the start of a polarity switch now, with the field getting a good deal more complicated than a simple dipole.
It's probable that the polarity switch is usually slow enough for most species that use magnetic navigation to adapt. However, the average field across Earth in the middle of the switch would be close to zero; which leads to all manner of interesting consequences including aurorae at the Equator and an increased mutation rate. Probably weather changes too, as solar protons get into the atmosphere.