Meteorites on Mars observed with the Mars Exploration Rovers

Reduced weathering rates due to the lack of liquid water and significantly greater typical surface ages should result in a higher density of meteorites on the surface of Mars compared to Earth. Several meteorites were identified among the rocks investigated during Opportunity’s traverse across the sandy Meridiani plains. Heat Shield Rock is a IAB iron meteorite and has been officially recognized as ‘‘Meridiani Planum.’’ Barberton is olivine-rich and contains metallic Fe in the form of kamacite, suggesting a meteoritic origin. It is chemically most consistent with a mesosiderite silicate clast. Santa Catarina is a brecciated rock with a chemical and mineralogical composition similar to Barberton. Barberton, Santa Catarina, and cobbles adjacent to Santa Catarina may be part of a strewn field. Spirit observed two probable iron meteorites from its Winter Haven location in the Columbia Hills in Gusev Crater. Chondrites have not been identified to date, which may be a result of their lower strengths and probability to survive impact at current atmospheric pressures. Impact craters directly associated with Heat Shield Rock, Barberton, or Santa Catarina have not been observed, but such craters could have been erased by eolian-driven erosion.Additional co-authors: DW Ming, RV Morris, PA de Souza Jr, SW Squyres, C Weitz, AS Yen, J Zipfel, T Economo

The limits of India’s ethno-linguistic federation: understanding the demise of Sikh nationalism

From 1984 until 1993, the Indian state of Punjab witnessed a sustained insurgency by Sikh militants campaigning for a separate sovereign state. This insurgency was ultimately defeated by the overwhelming use of security force that officially resulted in the deaths of 30,000 people. By the mid-1990s, a ‘normalcy’ had returned to Punjab politics, but the underlying issues which had fuelled the demand for separatism remain unaddressed. This paper examines critically the argument that India’s ethno-linguistic federation is exceptional in accommodating ethno-nationalist movements. By drawing on the Punjab case study, it argues that special considerations apply to the governance of peripheral regions (security, religion). Regional elites in these states struggle to build legitimacy because such legitimacy poses a threat to India’s nation and state-building. In short, India’s ethno-linguistic federation is only partially successful in managing ethno-linguistic demands in the peripheral Indian states