Astronomy and Astrophysics – Astronomy
Scientific paper
Oct 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010dps....42.6106e&link_type=abstract
American Astronomical Society, DPS meeting #42, #61.06; Bulletin of the American Astronomical Society, Vol. 42, p.1088
Astronomy and Astrophysics
Astronomy
Scientific paper
Recent Cassini radio tracking data has provided a normalized moment of inertia for Titan of 0.34 (Iess et al. 2010). Given that the quadrupole field is consistent with hydrostatic equilibrium, a two-layer interior model implies incomplete differentiation with a 700 km water-ice shell and an undifferentiated ice and rock-metal interior. We investigate the accretional history of Titan in connection with its internal structure. Our formation model allows for a size distribution of impactors with upper size cut-off constrained by Hyperion's size and a variable power-law exponent (Mosqueira et al. 2010). The burial of impact energy takes place in a lengthscale of order of the impactor radius, as indicated by numerical simulations (e.g., Pierazzo et al. 1997) applied to our energy regime of interest. Our thermal model includes radiogenic heating due to short and long-lived radionuclides, latent heat of melting, gravitational energy release due to sinking rock, heat of accretion and radiative cooling. We find that melting in the interior takes place well before the satellite reaches its final size. As a result, we expect the formation of an ocean overlying a silicate carapace, which may spend a considerable amount of time in contact with the liquid layer. Such a framework not only facilitates the transport of heat from the interior, but also can help both in leaching Ar40 into the ocean and then releasing into the atmosphere. We consider a range of parameters such as the degree of hydration of the rock component, the fraction of the impact energy that is deposited at the surface of the satellite, and accretion times. But we do not yet consider the effects of small admixtures of contaminants. We argue that models that form Titan in a cold environment may have allowed for the interior to remain cold enough as to preclude complete differentiation.
Estrada Paul R.
Mosqueira Ignacio
No associations
LandOfFree
Titan's Cold Accretion and its Internal Structure 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 Titan's Cold Accretion and its Internal Structure, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Titan's Cold Accretion and its Internal Structure will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1230417