These particles can affect a spacecraft, and in particular, the electrons may charge it negatively to hundreds and even thousands of volts, which could interfere with normal operations. With over 200 communication satellites inhabiting the synchronous orbit, there is obviously a good reason for studying substorm effects there. It is not easy to piece together a pattern from such observations, since most of the evidence comes from isolated satellites. What seems to happen is that magnetic field lines of the tail are first stretched tailwards and are then released, in a way frequently compared to the stretching and rebounding of a slingshot. As the lines bounce back, they propel and energize ions and electrons in the midnight region, at typical distances of 6-15 R E .
Most natural phenomena require an input of energy, which is then changed to some other form.
This also holds true for substorms. Such a shift leads to two effects. First, it weakens the Earth's magnetic field near noon, where plasma and field lines have been peeled off, allowing the solar wind to push its way closer to Earth. Secondly, more of the magnetic field is drawn into the tail, and the tail lobes expand , storing additional magnetic energy in them. It is widely believed that the expanded lobes are the main storehouse of energy which powers the substorm.