Jupiter – not to blame after all?

It is now generally accepted that, from a geochemical perspective, our Solar System is lumpy. In fact it comes in two very distinct lumps. This was pointed out by Paul Warren in his 2011 paper. He showed that when various isotopes (e.g. 54Cr, 62Ni, 50Ti), measured in a wide range of extraterrestrial materials, are plotted…

A big splash! – water and the giant impact

It is now widely accepted that the Moon formed as the result of a collision between two planet-sized objects. An event generally referred to as the giant impact. But that’s more or less where the consensus ends. There is currently little agreement on the relative size of the colliding bodies or the energy of the…

Earth’s doppelganger

A new paper in Nature presents some very interesting ideas about the evolution of the inner Solar System and by implication the nature of the bodies that collided in the giant impact to form the Earth-Moon system. Martin Schiller, Martin Bizzarro and Vera Assis Fernandes have looked at the calcium isotope composition of various inner…