Scientists find a long-sought electric field in Earth’s atmosphere
Once established, the field can act as a booster for lighter ions like hydrogen, giving them enough energy to break free of Earth’s gravity and zoom away as the polar wind.
Why NASA is sending a probe to Europa – and what it’s looking for
This, in addition to hints of geophysical activity – such as the rusty lines that streak its surface – and complex chemistry, is why Europa has long captivated astronomers searching for habitable worlds beyond our pale blue dot.