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Project Progress

Martian obliquity and climate history
We have developed an efficient way to simulate the rotational dynamics of Mars, using the results of long-term orbital simulations as forcing. We can simulate 100 million years in a few minutes. We have coupled the dynamics to simple models of deformations and changes in volatile and dust distribution. Since the system is both chaotic and dissipative, its past evolution is difficult to constrain. We have found that realistic volatile loads can significantly change obliquity evolution. In particular, it is now much less certain whether Mars had periods of high obliquity in the past few hundred million years.

General rotational dynamics
A great deal of effort was devoted to derive a new general theory for the rotational dynamics of planets and satellites which is capable to predict evolution due to tides. We are now able to tell whether tides can drive obliquity to extreme values.

Chaos in the inner solar system
We carried out a detailed analysis of our numerical simulation results of our solar system. We have found that chaos in the inner solar system has two sources. While the chaotic interaction between Earth and Mars is the main source of chaos, there is smaller component in the interaction of Venus and Mercury. Surprisingly, the system is presently in a transition to a more chaotic state.