In early December, observers in northern Norway will be treated to an unusual show: a sounding rocket double feature. Arcing up over the Norwegian sea, the first rocket will blast off to an altitude of more than 600 miles high, headed due north. Approximately two minutes later, at a lower altitude, another rocket will follow its path.
These twin rockets are chasing down a mystery about magnetic reconnection, the explosive process that allows charged particles from space to stream into Earth’s atmosphere. Carefully observing anomalies in this stream of particles, scientists have wondered about the processes that let them in: Does magnetic reconnection turn on and off, like a faucet, or do particles course in from separate locations, like the distinct streams of a sprinkler?
Armed with two rockets and a clever experimental design, the scientists behind the TRICE-2 mission, short for Twin Rockets to Investigate Cusp Electrodynamics-2, hope to uncover an answer. The results promise to shed light on the fundamental process of magnetic reconnection and, in the long run, help us better predict how and when Earth’s magnetic shield can suddenly become porous and let outside particles in.