Mercury's Geomagnetic Storms Are Similar to Farth's.

• Position: PLANETS

Mercury, our solar system's smallest planet, has geomagnetic storms similar to those on Earth, according to research by an international team of scientists from the U.S., Canada, and China. The finding, a first, answers the question of whether other planets, including those outside our solar system, can have geomagnetic storms regardless of the size of their magnetosphere or whether they have an Earth-like ionosphere.

A geomagnetic storm is a major disturbance in a planet's magnetosphere caused by the transfer of energy from the solar wind. Such storms in Earth's magnetosphere can disrupt radio communications.

'The processes are quite similar to here on Earth," says Hui Zhang, a space physics professor at the University of Alaska's Geophysical Institute. He points out that both Earth and Mercury possess ring currents --electric currents carried by charged particles trapped in a planet's magnetosphere. "The main differences are the size of the planet and Mercury has a weak magnetic field and virtually no atmosphere."

Confirmation about geomagnetic storms on Mercury results from research made possible by a...