For 350 years after Galileo's discoveries, ground-based telescopes and theoretical modelling furnished everything known about the Sun's planetary retinue. Over the past five decades, data from spacecraft sent to all the planets and some of their satellites have shown the diversity of Solar System bodies. Many planets and satellites have changed substantially since their birth, and violent events punctuate their histories.

Using historical data combined with more recent satellite observations, these authors show that global phytoplankton biomass has been declining during the past century.

Non-classical states of light, such as entangled photon states, form an essential quantum resource. Entangled photon pairs can be created by spontaneous parametric down-conversion of laser light, but so far it has not been possible to produce photon triplets in this way. These authors report the generation of quantum-correlated photon triplets by cascaded down-conversion of a single pump photon. This should find widespread use in optical quantum technologies.