NASA's Polar satellite monitors Earth's polar auroral regions. A substorm is shorter, lasting up to a couple of hours and results from the energy stored in the magnetotail being released and accelerated toward the Earth. Geomagnetic substorms are not particularly rare, and as we approach the solar maximum in mid-2000 we will see a lot of coronal holes, solar flares, and other events on the Sun which trigger magnetic disturbances. Our planet's magnetic field does a good job protecting the surface of Earth from solar wind storms. Life on Earth depends on our magnetic shield.
Scientists think our neighboring planet, Mars, formerly had oceans and an atmosphere.
Venus also has no appreciable magnetic field, and has lost nearly all of its water to space, in large part due to the action of the solar wind. The Aurora Fortunately for aurora lovers, the magnetosphere is not invincible. Strong bursts of solar wind can also squeeze our magnetosphere, compressing it until it bounces back like a vibrating rubber ball. Dr. Jim Spann is a scientist at NASA's Marshall Space Flight Center. Coronal Holes Regions where the corona of the Sun is dark when viewed in X-rays.