Alignment of satellites on 25 November 2001

This animation shows the positions of the satellites during the event on 25 November 2001.

During an opportune alignment that occurred during the recovery phase of a large geomagnetic storm, observations with different instruments from several different points were carried out.

A low frequency type of ULF wave, comparable to a beep every 10 minutes, was recorded continuously for many hours by the CARISMA magnetometer chain in Northern Canada. The waves were picked up by more than a dozen scientific satellites including the four ESA Cluster satellites, NASA’s Polar spacecraft and four of the Geostationary Operational Environmental Satellites (GOES).