The low-energy ions begin in the upper portion of our atmosphere called the ionosphere. Here solar energy can strip electrons from molecules, leaving atoms such as oxygen and hydrogen with a positive charge. However, physically finding these ions has been problematic. While researchers knew they existed at altitudes of about 100 kilometers (60 miles), Andre and colleague Chris Cully set their sites higher – at between 20,000 and 100,000 km (12,400 to 60,000 mi). At the edge, the amount of cold ions varies between 50 to 70%… making up most of the mass of space.


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