Here, the atmosphere of the extrasolar planet GJ 436b is studied during its 'secondary eclipse'. The findings reveal the presence of some H2O and traces of CO2. The best-fit compositional models contain a high CO abundance and a substantial methane deficiency relative to thermochemical equilibrium models for the predicted hydrogen-dominated atmosphere. Disequilibrium processes such as vertical mixing and polymerization of methane may be required to explain this small methane-to-CO ratio

Atom chips provide a versatile quantum laboratory for experiments with ultracold atomic gases, but techniques to control atomic interactions and to generate entanglement have been unavailable so far. Here, the experimental generation of multi-particle entanglement on an atom chip is described. The technique is used to produce spin-squeezed states of a two-component Bose–Einstein condensate, which should be useful for quantum metrology

The accumulation of nitrate in freshwater and coastal marine ecosystems is one of the consequences of the worldwide production of artificial fertilizers. Here it is shown that nitrate accumulation in ecosystems shows consistent and negative nonlinear correlations with organic carbon availability, along a continuum from soils, through freshwater systems and coastal margins, to the open ocean. This pattern can be explained by carbon:nitrate ratios, which influence nitrate accumulation by regulating microbial processes