We compare published solutions for the rotation angle W(t) which describes the location of the prime meridian of Mars with respect to the ICRF equator in IAU recommendations. If the model for W includes a very long period term, we transform it into a quadratic polynomial with updated epoch value and rate, resulting in a difference in the mean epoch value up to 200 km. The mean and true epoch rotation angles are about 800 mas (13 m) apart in J2000 and should not be confused with each other in order to accurately locate the prime meridian. We identify two groups of radio-science solutions for W, which can be distinguished by the prime meridian location they used as a priori that differ from each other by about 100 m at J2000.

This article examines the development, handling, and depositions of disc-on-bow brooches from the sixth to tenth centuries ad in the Vendel and Viking periods in Norway and mainland Sweden. A revised typological framework is presented, and the context of these brooches explored. The authors discuss their preservation, re-use, fragmentation, and ritual meaning within ongoing social negotiations and internal conflicts from the late Vendel period into the Viking Age. References to the past in Viking-Age society and the significance of women for maintaining narratives of the past are considered, as are levels of access, control, and definition of narratives of the past in times of social redefinition.

The discovery of a tenth-century AD high-status burial at Prague Castle in 1928 led to multiple identifications in the context of two world wars and the Cold War. Recognised variously as both a Viking and Slavonic warrior according to Nazi and Soviet ideologies, interpretation of the interred individual and associated material culture were also entangled with the story of the burial's excavator, the remains and commemorative monuments of two Czech Unknown Soldiers and the creation of the Czechoslovak state. This epic narrative reflects the circumstances of Czechoslovakia and Central Europe across the twentieth century.

In Anglo-Saxon and Viking literature swords form part of a hero's identity. In addition to being weapons, they represent a material agent for the individual's actions, a physical expression of identity. In this article we bring together the evidence from literature and archaeology concerning Anglo-Saxon and Viking-age swords and argue that these strands of evidence converge on the construction of mortuary identities and particular personhoods. The placement of the sword in funerary contexts is important. Swords were not just objects; they were worn close to the body, intermingling with the physical person. This is reflected in the mortuary context where they were displayed within an emotive aesthetic. Typically, swords were embraced, placed next to the head and shoulders, more like a companion than an object. However, there are exceptions: graves like Birka 581 and Prittlewell show sword locations that contrast with the normal placement, locations which would have jarred with an observer's experience, suggesting unconventional or nuanced identities. By drawing on literary evidence, we aim to use the words of the Anglo-Saxons and Vikings to illuminate the significance of swords in mortuary contexts and their wider cultural associations.

Metal detecting in England has recovered a large number of Viking Age single finds that have been reported to the Portable Antiquities Scheme. These reveal that silver bullion of Scandinavian origin was used as currency throughout the Danelaw between AD 865 and 940. Standardised weights of copper alloy were an integral part of this metal-weight economy. Bullion was not the sole means of silver payment during this period: coinage had long been used in the occupied Anglo-Saxon territories and continued to be minted under the Vikings. The resulting dual-currency economy may have facilitated trade with neighbouring Scandinavian territories, but the two currencies also served as markers of cultural identity, offering a choice of monetary media.

A rare, intact Viking boat burial in western Scotland contained a rich assemblage of grave goods, providing clues to the identity and origins of both the interred individual and the people who gathered to create the site. The burial evokes the mundane and the exotic, past and present, as well as local, national and international identities. Isotopic analysis of the teeth hints at a possible Scandinavian origin for the deceased, while Scottish, Irish and Scandinavian connections are attested by the grave goods. Weapons indicate a warrior of high status; other objects imply connections to daily life, cooking and work, farming and food production. The burial site is itself rich in symbolic associations, being close to a Neolithic burial cairn, the stones of which may have been incorporated into the grave.

This paper was conceived as a keynote lecture for the Medieval Europe Research Congress (MERC) 2012 in Helsinki. The author himself has gone a long way from the more or less exclusively ship-functionalist perspective he presented at the first conference of this kind, Medieval Europe in 1992 in York. The intention here is to inspire other maritime archaeologists who may be stuck in studying ship technologies to apply their knowledge in contextual and cross-disciplinary approaches to ships, landscapes, and the human mind of the Middle Ages. A few examples of possible ways are discussed, albeit admittedly incompletely. These include a number of examples from the author's own research, which were strongly under the influence of a functionalist and techno-practical perspective in the 1990s.

Vikings with artificially modified teeth have previously been documented in the south-eastern parts of Scandinavia and in England. In a project dealing with life in the Mälaren Valley in Sweden during the period AD 750–1100, new cases of people with modified maxillary teeth were observed. The hypothesis that the practice was entirely associated with adult men dating to the Viking Age was tested. The new cases demonstrate that the habit extended to eastern-central Sweden, including the proto-town of Birka, perhaps as early as in the middle of the eighth century. Additionally, cases from Sigtuna show that the practice may have ended as late as the beginning of the twelfth century. A microanalysis, using a scanning electron microscope, showed the heterogeneous character of the modifications. The affected individuals were all adult men, similar to previously published cases. Some of the men are associated with weapons and violent acts and the cases from Sigtuna were all from cemeteries with a possible association with lower social strata. However, discrepancies in archaeological contexts and in the characteristics of the modifications suggest temporal and spatial variation in the social meaning of the modifications.

There have been several attempts to answer the question of whether there is, or has ever been, life on Mars. The boldest attempt was the only ever life detection experiment conducted on another planet: the Viking mission. The mission was a great success, but it failed to provide a clear answer to the question of life on Mars. More than 30 years after the Viking mission our understanding of the history and evolution of Mars has increased vastly to reveal a wetter Martian past and the occurrence of diverse environments that could have supported microbial life similar to that on Earth for extended periods of time. The discovery of Terran extremophilic microorganisms, adapted to environments previously though to be prohibitive for life, has greatly expanded the limits of habitability in our Solar System, and has opened new avenues for the search of life on Mars. Remnants of a possible early biosphere may be found in the Martian meteorite ALH84001. This claim is based on a collection of facts and observations consistent with biogenic origins, but individual links in the collective chain of evidence remain controversial. Recent evidence for contemporary liquid water on Mars and the detection of methane in the Martian atmosphere further enhance the case for life on Mars. We argue that, given the cumulative evidence provided, life has and is likely to exist on Mars, and we have already found evidence of it. However, to obtain a compelling certainty a new mission is needed, one which is devoted to the detection of life on Mars.

Instances of cultural interaction between Norse and native American have long been accepted. But current archaeological research recognises that the indigenous peoples of the north were themselves diverse and had diverse histories. Here the author shows that the culture of one of them, the Dorset people, owed nothing to the Norse and probably had no contact with them.

High in the mountains between Norway and Sweden, archaeological survey has brought to light a trail marked by standing stones at regular intervals and tall enough to show above the winter snows. In the absence of any cultural material, the erection of the stones was dated by the diameter of the lichen spreads upon them, and corroborated by a study of the documents and radiocarbon dates. The authors argue that this was not an indigenous trail but one constructed by a Norse chieftain probably around the ninth century AD to gain safe access to the fur-trading Sami.

The adaptability of extremophiles on Earth raises the question of what strategies putative life might have used to adapt to the present conditions on Mars. Here, we hypothesize that organisms might utilize a water–hydrogen peroxide (H2O–H2O2) mixture rather than water as an intracellular liquid. This adaptation would have the particular advantages in the Martian environment of providing a low freezing point, a source of oxygen and hygroscopicity. The findings by the Viking experiments are reinterpreted in light of this hypothesis. Our conclusion is that the hitherto mysterious oxidant in the Martian soil, which evolves oxygen when humidified, might be H2O2 of biological origin. This interpretation has consequences for site selection for future missions to search for life on Mars.