Mercury isn't a bit like it was supposed to be. NASAs Messenger spacecraft shows craters on the planet that are deep and cold enought to hold frozen water – but Mercury is the rock closest to the Sun. Images of other regions indicate large eruptions have taken place – which somehow they can date to 3.7 billion years ago. When journalists or press releases express these numbers with such certainty one can't help being amused – but then again someone must have fed them the information. Craters are in fact thought to be buried beneath the lava – or basalt floor of the planet. Some fast tracking on the part of somebody seems to be appropriate. High levels of sulphur and potassium have also been detected – elements that evaporate early and should not really be lurking around. As data pours in from Messenger novel interpretations are being aired. No doubt this will eventually gell into the prevailing consensus – stretch its credibility a little, but basically made to agree (see www.sciencenews.org/view/generic/id/331505/title/Messages_from_Mercury/).
Odd Mercury
19 June 2011Astronomy