Sunny Solar Impulse 2 August 2, 2016 by World Book | Tuesday, August 2, 2016 | Last week, on July 26, the solar-powered airplane Solar Impulse 2 landed in Abu Dhabi in the... Business & Industry, Conservation, Current Events, Energy, Environment, Science, Technology. solar energyairplaneaviation Read More Africa's Deep Helium Pool by World Book | Thursday, July 7, 2016 | Photo Credit: © AP Photo: Helium lifts weather balloons high into the atmosphere to record and... Business & Industry, Current Events, Energy, Science. Africagasheliumweather balloon Read More