Small Body Grooves, Theories for the formation of grooves on Lutetia and Phobos Options

[Phil Stooke]

The best set of grooves on any object since Phobos. This has to put an end to the 'grooves caused by Mars ejecta' argument. fantastic object and a wonderful data set. And this is just the highest priority data, all the rest still to come.

Phil

[bk_2]

The best set of grooves on any object since Phobos. This has to put an end to the 'grooves caused by Mars ejecta' argument. fantastic object and a wonderful data set. And this is just the highest priority data, all the rest still to come.

Phil

The similarities with Phobos are striking, the photos clearly show two families of roughly parallel grooves, in two different planes. But the grooves seem to have been obliterated over most of the surface by later big impacts.

Once again I have to say they look like the tracks of intersection with rings, edge on. What else could carve a long smooth trench on the surface of a large object in space? Where Lutetia might have encountered rings is not going to be easy to answer, the chaos of the early Solar System is way beyond our scrutiny. The grooves do seem to be very old features, pockmarked with small craters, as well as restricted to areas clear of debris from the big ones.

[Phil Stooke]

Organized grooves seem to me to require a fractured monolith. Impact jostling of the pieces could open those fractures to produce the observed bulk porosity, but the grooves could be linear.

Phil