Ions in lunar landing
Earth may have been leaking oxygen on to the moon for billions of years. Our planet鈥檚 magnetic field not only protects the moon from the solar wind, it also creates a sheet of ions that stream between the two, carrying hydrogen as well as oxygen (Nature Astronomy, ).
Smoking鈥檚 extra costs
Smoking accounts for almost 6 per cent of global healthcare spending, and its economic impact equals 1.8 per cent of global GDP. In 2012, that impact amounted to 拢1.15 trillion, with nearly 40 per cent of it borne by less-developed nations, according to data from 152 countries (Tobacco Control, ).
Practice makes perfect
Don鈥檛 stop just yet. A study involving 183 people learning a new task finds that to really master something, we should keep practising even when we no longer think we can get any better. Such 鈥渙verlearning鈥� may help cement improvements in performance (Nature Neuroscience, ).
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Sunken continent find
A long-lost continent has been found submerged deep in the Indian Ocean. Plate tectonics that drew India and Madagascar apart stretched it like plasticine, causing it to sink some 85 million years ago. Ancient zircon crystals brought up in lava on Mauritius have now revealed it (Nature Communications, ).
Fish use wee-mails
Urinating at rivals is all part of one cichlid fish鈥檚 territorial display. When fish separated by a transparent barrier couldn鈥檛 detect their opponent鈥檚 urine, they showed more hostile behaviour and urinated more often, presumably to get their message across. The barrier also made fish more likely to attack larger opponents (Behavioral Ecology and Sociobiology, ).
