Nasa’s rocket aimed at unraveling one of Earth’s mysteries

In the polar cusp, spacecraft inexplicably slow down. The goal of the mission is to understand what happens in the area created by a gap in the magnetic field.

Nasa wants to solve one of Earth's mysteries: what happens in the polar cusp. The area is located above our planet, at noon local time on the Arctic and Antarctic circles. It is a special zone created by a gap in the magnetic field of the globe, a place where the Sun's plasma meets our atmosphere. Here, 400 kilometers above the ground, spacecraft inexplicably slow down. The U.S. space agency, with the Cusp Region Experiment-2, or CREX-2, a rocket mission, plans to discover the reason for this slowdown.

The Polar Cusp Region

Our planet's atmosphere at the Polar Cusp is very tenuous, but it is not a perfect vacuum. Something is holding back spacecraft. "At about 250 miles above Earth, spacecraft feel more resistance, kind of like hitting a bump," Dr. Mark Conde, a physicist at the University of Alaska Fairbanks and CREX-2 principal investigator, said in a statement. "That's because the air in the cusp is significantly denser than air elsewhere in spacecraft orbits around Earth. But no one knows why or how." In the polar cusp, the mass would be 1.5 times greater than in any other area of the planet. The rocket to be sent by Nasa aims to understand how it manages to stay at that altitude. "You can't just increase the mass in a region by a factor of 1.5 and not do anything else, or the sky will fall," Conde explained.

Nasa's rocket mission

To understand how the extra mass stays 400 kilometers above the ground, the rocket will study the electrical and magnetic effects of the interaction between the Sun's charged particles and the upper atmosphere. It will also measure the behavior of winds, which could provide support for a number of possible scenarios. The rocket will release 20 containers the size of a soda can, each with its own rocket motor. They will launch in different directions and release vapor trails at different altitudes. These are the same particles found in fireworks. Glowing from exposure to oxygen and capturing sunlight, they will create bright clouds that would allow scientists to understand what is happening inside the cusp.

To make the experiment work, however, good weather conditions are needed both to launch the rocket and to observe the clouds from the right spots at the right time since there can't be too much light. The winter months are ideal and the researchers will be placed throughout Scandinavia, in the Svalbard Islands and even on a plane from Reykjavík, Iceland. Once the most suitable date for the mission has been identified, CREX-2 will be launched from Andenes in Norway.

About Earth, however, it was recently discovered what brought water to our planet and that the globe is becoming less bright. Another study analyzed what is hidden in the diamond in the depths of the Earth's sphere.

Stefania Bernardini