The megalithic monuments of Arles–Fontvieille appear to have been deliberately constructed such that a ray of the setting sun on and around the equinox penetrates the subterranean chamber producing a spectacular light-and-shadow hierophany. Moreover, at one of the sites there is evidence in the form of rock art that observations were also being made of heliacal rising and settings, possibly of both the Pleiades and Orion. The equinox hierophany has been documented at three of the four intact monuments of the group. This phenomenon was probably exploited for sacred ritualistic purposes related to seasonal change and timekeeping by the agricultural people who built the monuments. This evidence has significant importance for understanding these monuments in the context of European megalithism and the wider European Neolithic as well as for understanding their cosmological role within the society that built them.

The helium ion microscope is a unique imaging instrument. Based on an atomic level imaging system using the principle of field ion microscopy, the helium ion source has been shown to be incredibly stable and reliable, itself a remarkable engineering feat. Here we show that the image contrast is fundamentally different to other microscopes such as the scanning electron microscope (SEM), although showing many operational similarities due to the physical ion interaction mechanisms with the sample. Secondary electron images show enhanced surface contrast due the small surface interaction volume as well as elemental contrast differences, such as for nanowires imaged on a substrate. We present images of nanowires and nanoparticles for comparison with SEM imaging. Applications of Rutherford backscattered ion imaging as a unique and novel imaging mechanism are described. The advantages of the contrast mechanisms offered by this instrument for imaging nanomaterials are clearly apparent due to the high resolution and surface sensitivity afforded in the images. Future developments of the helium ion microscope should yield yet further improvements in imaging and provide a platform for continued advances in microscope science and nanoscale research.

This is a brief introduction to the ideas behind the art installation Siderea, Homage to Galileo that was created for, and exhibited at the IYA 2009 Opening Ceremony at UNESCO in Paris. The text narrates the attraction that astronomy exercises on the author, who studied Classics before becoming an artist and has always been fascinated by science.