NASA is gearing up for the launch of two sounding rockets - CAPER and RENU 2 - that will soar into the Northern Lights this winter. The goal is to study particle movement in an area near the North Pole where Earth's magnetic field is directly linked to the solar wind.

Both CAPER and RENU 2 are involved in the analysis of the cusp aurora phenomenon, a subcategory of the Northern Lights wherein particles are speeded downward into the Earth's atmosphere straight from the solar wind. A cusp aurora is not a rare phenomenon but it only happens during daytime. This makes the phenomenon difficult to spot as the daytime brightness covers the light show. CAPER and RENU 2 will utilize ground-based radar data to spot the cusp auroras even during the presence of clouds.

A Tale Of Two Rockets

CAPER stands for Cusp Alfven and Plasma Electrodynamics Rocket, which is set to launch first this winter. The rocket is set to investigate the electromagnetic (EM) waves that drive the electrons responsible for the light show. The electrons that speed downward into the Earth collide with particles suspended in the atmosphere, which releasing light and creating the cusp aurora.

CAPER will carry three instruments that will document low-frequency EM waves, high-frequency EM waves and the number of particles present at various energy levels. CAPER principal investigator Jim LaBelle stressed the difficulty in gauging high-frequency EM waves and the particles associated with them.

"They're moving at up to a million cycles per second, so the instruments have to be able to detect changes in the waves and collect enough particles to match up," said LaBelle.

RENU stands for Rocket Experiment for Neutral Upwelling. RENU 2 is the second version of the rocket, and it will analyze the link between the influx of electrons that produces the cusp aurora, the heated neutral atoms located in the upper atmosphere and the electric currents along the planet's magnetic field lines.

The rocket launches are supported through NASA's Sounding Rocket Program. The launch window will open on Nov. 27, but the exact date and time of the launches will depend on the presence of a cusp aurora and favorable weather conditions.