Cluster Path through Aurora Region (IMAGE) European Space Agency Caption The Cluster C3 and C1 satellite trajectories between 16:55 and 17:15 UT on June 5, 2009. During this period, both satellites were able to send back data about conditions in the auroral acceleration region of Earth's dusk-side aurora. C3 flew through the region at an altitude of about 6,400 km (one Earth radius or RE), while C1 was flying at approximately 9,000 km (1.4 RE) and lagging about five minutes behind. The blue ovals indicate the poleward half of the auroral oval, which is characterized by upward currents in the dusk-side magnetic field. Credit ESA Usage Restrictions For non-commercial use only. For free use only with full credit line indicated. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.