Mathematics – Logic
Scientific paper
Jan 1997
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997stin...0247559z&link_type=abstract
Technical Report, 1997 Chapman Venus Conference
Mathematics
Logic
Planetary Craters, Monte Carlo Method, Computerized Simulation, Venus (Planet), Venus Surface, Geochronology, Projectile Cratering, Lunar Craters
Scientific paper
Impact craters on Venus appear to be uniformly and randomly scattered over a once, but no longer, geologically active planet. To first approximation, the planet shows a single surface of a single age. Here we use Monte Carlo cratering simulations to estimate the age of the surface of Venus. The simulations are based on the present populations of Earth-approaching asteroids, Jupiter-family, Halley-family, and long period comets; they use standard Schmidt-Housen crater scalings in the gravity regime; and they describe interaction with the atmosphere using a semi-analytic 'pancake' model that is calibrated to detailed numerical simulations of impactors striking Venus. The lunar and terrestrial cratering records are also simulated. Both of these records suffer from poor statistics. The Moon has few young large craters and fewer still whose ages are known, and the record is biased because small craters tend to look old and large craters tend to look young. The craters of the Earth provide the only reliable ages, but these craters are few, eroded, of uncertain diameter, and statistically incomplete. Together the three cratering records can be inverted to constrain the flux of impacting bodies, crater diameters given impact parameters, and the calibration of atmospheric interactions. The surface age of Venus that results is relatively young. Alternatively, we can use our best estimates for these three input parameters to derive a best estimate for the age of the surface of Venus. Our tentative conclusions are that comets are unimportant, that the lunar and terrestrial crater records are both subject to strong biases, that there is no strong evidence for an increasing cratering flux in recent years, and that that the nominal age of the surface of Venus is about 600 Ma, although the uncertainty is about a factor of two. The chief difference between our estimate and earlier, somewhat younger estimates is that we find that the venusian atmosphere is less permeable to impacting bodies than supposed by earlier studies. An older surface increases the likelihood that Venus is dead.
McKinnon William B.
Zahnle Kevin J.
No associations
LandOfFree
The Age of the Surface of Venus does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Age of the Surface of Venus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Age of the Surface of Venus will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1199132