SOLAR STORY: About 3.5 billion years ago, Earth faced a bombardment of solar wind (shown here in a NASA illustration) that likely stripped much of the water out of the young planet’s atmosphere. That’s according to new research led by Rochester geophysicist John Tarduno that indicates the Earth’s magnetosphere, the boundary where the planet’s magnetic field shields the planet from the energetic particles released by the Sun, was once only half as strong as it is today. The work was published this spring in the journal Science.