Mantle unmixed; Aurora gets the goahead; Charon pinned down; Dark skies for a car park; Sirius B balances the Sun; Liverpool on the Honours List; Middle-sized black hole; Dark galaxy found

Abstract

Sue Bowler, Editor This issue contains a very satifying example of a step forward in science, when conflicting data and ideas resolve themselves into a new and clearer picture thanks to advances in data collection, modelling and so on. The example is excellently described by George Helffrich in his Bullerwell Lecture, which elegantly explains how the emerging geophysical picture of a mantle mixing throughout its depth conflicts with the geochemical view of distinct regions, chemically isolated and unable to mingle. The lesson of this review is that different viewpoints allow observers to see different things. The geochemical picture defined characteristics of distinct parts of the mantle, without locating them, whereas the geophysical view showed where such isolated volumes of rock could not be, but can see only fuzzily what the different rocks might be. Together, however, they now have a vastly improved picture of around half the planet, and one that in turn provides a framework for future research in all aspects of the deep Earth. But this is also a lesson for scientists in general. One point of view, whether a fixed opinion or a limited collection of data, is not enough. Astronomers have in the past few years seen a comparable explosion of data, thanks again to improved data collection and handling methods, and to the larger observatories now available. The boost in this field has been the availability of multiwavelength data, so that astrophysicists can now examine objects such as gamma-ray bursters in full colour, as opposed to the monochrome views of the past, that used only a fraction of the electromagnetic spectrum. Planetary science, solar– terrestrial physics, and all branches of astrophysics are benefitting in the same way from this avalanche of data. Long may it continue – as long as the development of data storage and handling methods keeps pace, or we will all drown in data. EDITORIAL