One of the long-standing questions in planetary science is how Earth has water and life, and other planets, like Venus, don’t. A key part of the solution may be the electrical fields of both planets. The Venus Express mission found that the electrical field had a strong electrical potential. This means the field could have pulled apart the positively charged water molecules and blasted them into space. The Earth may have a weaker electrical potential in its magnetic field, and scientists think that this is the reason why Earth still has its water.

To figure this out, a team will determine how much electrical potential the Earth’s magnetic field has. They estimate it to be 25 times weaker than Venus. The measurement is made indirectly. Earth’s atmosphere has electrons moving away at a known speed, and any variation in the speed will be caused by the electrical potential.

More Information

NASA Goddard press release