Venus hypothesis

Venus hypothesis

1. Early Venus

   • If plate tectonics on Venus had been active they must have ceased before the stagnant lid phase
     • Violent resurfacing occuring by about 600-400 My BP
   • Stagnant lid period would have seen increasing pressure beneath the crust
     • Volcanic eruptions + impacting asteroids = more material ejected from Venus's surface
       • escape velocity of Venus = 10km/s, + impulse of 22km/s required to just reach earth
         • Take 150 days to travel
         • Hohnman Transfer orbit calculation

2. Cambrian Explosion, Great Ordovician Biodiversity event

   • Complex life suddenly appeared with Cambrian explosion 540My BP
     • Timings and duration for these all coincide with one another
     • Major challenge in the study of evolution on Earth
   • GOBE 460My BP diversity greatly increased.
   • models to describe them
     • Timings
       • No theories convincingly address all these questions
     • Why did it start
     • Why did it stop
     • why was this period unique
       • Lack of earlier fossils which have genetic correlation
     • GPBE: Timings of significant changes are diachronous across groups, enviroments and regions

3. How the VH solves the problems

   • Timing of material from Venus dictated by the violent resurfacing
     • Possibly exacerbated by the break up of the L-chondrite parent asteroid. 470My BP
   • Lack of precursor fossils explained by them being left on Venus
   • Geographical inconsistencies expected as meteorites carry new life, others destroy established communities
   • Genetic diversity expected as interesting beings could form on Venus due to its closer proximity to the sun and the different conditions
     • About twice the intensity of solar radiation and solar wind experienced on Earth
     • Tidal derotation, longer days
       • negligible magnetic fields
     • Exposure to radiation increases rate of mutation
       • more exotic and advanced in evolving than that on Earth