A solar-powered airplane finished crossing the United States on Saturday, landing in New York City after flying over the Statue of Liberty during its historic bid to circle the globe, the project team said. The spindly, single-seat experimental aircraft, dubbed Solar Impulse 2, arrived at New York's John F. Kennedy International Airport at about 4 a.m. local time after it took off about five hours beforehand at Lehigh Valley International Airport in Pennsylvania, the team reported on the airplane's website. Such a pleasure to land in New York! For the 14th time we celebrate sustainability," said the project's co-founder Andre Borschberg on Twitter after flying over the city and the Statue of Liberty during the 14th leg of the trip around the globe. The Swiss team flying the aircraft in a campaign to build support for clean energy technologies hopes eventually to complete its circumnavigation in Abu Dhabi, where the journey began in March 2015. The solar cr...
If this volume is hard to visualise, imagine the Earth's entire land surface covered in a layer some 180m deep. The new calculation comes from a Canadian-led team and is published in the journal Nature Geoscience. Significantly, little of this water - just 6% - is the kind of bankable resource that is most useful to people. That small fraction is referred to as "modern" groundwater: it is extractable because it is near the surface, and can be used to supplement above-ground resources in rivers and lakes. It's the groundwater that is the most quickly renewed - on the scale of human lifetimes," explained study leader Tom Gleeson from the University of Victoria. And yet this modern groundwater is also the most sensitive to climate change and to human contamination. So, it's a vital resource that we need to manage better."To quantify just how much water is stored in the top 2km of the Earth's surface, Dr Gleeson's team had to combine larg...