© 2015

The Twin Sister Planets Venus and Earth

Why are they so different?


  • A comprehensive model for the evolution the planet Earth and Venus over Geologic Time

  • Offers a new approach to the intact capture model

  • Contains proposed tests of the models presented

  • Has many significant implications for the argument that habitable planets may be fairly rare in a large region of space


About this book


This book explains how it came to be that Venus and Earth, while very similar in chemical composition, zonation, size and heliocentric distance from the Sun, are very different in surface environmental conditions. It is argued here that these differences can be accounted for by planetoid capture processes and the subsequent evolution of the planet-satellite system. Venus captured a one-half moon-mass planetoid early in its history in the retrograde direction and underwent its “fatal attraction scenario” with its satellite (Adonis).  Earth, on the other hand, captured a moon-mass planetoid (Luna) early in its history in prograde orbit and underwent a benign estrangement scenario with its captured satellite.


Circular Maria Cool Early Earth Lunar Mascons Lunar Rock Magnetization Orbit Resonances Prograde Capture Retrograde Capture Tidal Capture Vulcanoid Planetoids X-wind Model

Authors and affiliations

  1. 1.Geosciences DepartmentDenison UniversityGranvilleUSA

About the authors

Bob Malcuit received his Bachelor and Master degrees in Geology from Kent State University in 1968 and 1970 and his Ph.D. in Geology from Michigan State University in 1973.  He taught in the Geosciences Department at Denison University from 1972 to 1999.  His main research interests throughout his teaching career and in retirement are in the field of Planetary Geology.

Bibliographic information


“The book presents a highly detailed discussion of the idea, which has clearly been a long-term research interest of the author. … The book will therefore be very interesting to specialists in the field, and it contains a wealth of detail, diagrams, many examples of computer simulations, and many references. … The detailed Glossary will be helpful for the non-specialist reader.” (Richard McKim, The Observatory, Vol. 136 (1250), February, 2016)