Have you exhausted the possibilities in Google Earth – unlikely – then why not try Google Mars (www.google.com/mars)? Well it’s a bit early, as the site is still under construction, and does not yet include the features that enrich the Google Earth experience or the full planetary surface. Nevertheless the University of Arizona, which produced the data mosaics, has provided a bright, colour-coded elevation map and mosaiced images in visible and infrared wavelengths that show enough detail to easily examine many of the landforms for which the ‘Red Planet’ has become renowned.  It is a fine resource for targeting users to find specific kinds of feature – craters, dunes, water-carved valleys and lava flows. Once complete it should satisfy anyone who wants to explore, probably including those with delusions of ‘boldly going…’ before they become too old and infirm….

Breathing life into ‘Snowball Earth’

Paul Hoffman’s hypothesis of episodes, mainly in the late-Precambrian, when Earth was encapsulated in ice from pole to pole has taken repeated knocks since he first proposed it. It seems only natural that he should make the evidence and his ideas more publicly available on the Web – http://www.snowballearth.org. ‘Snowball Earth’ is a live and important aspect of geoscientific debate, for a whole raft of reasons, and it continually evolves. Although Hoffman does use the site as a vehicle for rebuttals to all the objections that further research has raised, it is a great deal more interesting and useful than that: a very well produced resource for anyone interested in a crucial period – the Neoproterozoic – in the evolution of life. Additionally, it helps budding geoscientists come to grips with the intellectual and experimental processes involved in major advances in knowledge and understanding. Besides which, it will save Hoffman a small fortune in air fares to have his say to live audiences!