A cubical satellite small enough to sit on the palm of your hand is zipping around the world and sending data about radiation to the Louisiana students who designed and built it.

The satellite, called CAPE-3, carries a chip designed and built by students at the University of Louisiana at Lafayette to detect radiation, with an eye to keeping astronauts safe.

"The detectors would provide liquid crystal display readings so astronauts could constantly monitor how much radiation they're being exposed to," Dr. Paul Darby, the university's project leader, said in a news release.

The satellite also carries a tiny Geiger counter so students can tell whether the chip is accurate.

Each side of the satellite is only 10 centimeters—less than 4 inches—across. It was among 10 launched Jan. 17 from a Virgin Orbit rocket that itself was launched high above the Pacific Ocean from a customized Boeing 747.

Eight of the other nine were built by students at other schools. The tenth was built by NASA, which runs the CubeSat Launch Initiative to give nonprofit organizations and schools at all levels a chance to do scientific investigations in space and help NASA with exploration and technology development.

The Sun's extremely hot outer layer, the corona, has a very different chemical composition from the cooler inner layers, but the reason for this has puzzled scientists for decades.

One explanation is that, in the middle layer (the chromosphere), magnetic waves exert a force that separates the Sun's plasma into different components, so that only the ion particles are transported into the corona, while leaving neutral particles behind (thus leading to a build-up of elements such as iron, silicon and magnesium in the outer atmosphere).

Now, in a new study published in The Astrophysical Journal, researchers combined observations from a telescope in New Mexico, the United States, with satellites located near Earth to identify a link between magnetic waves in the chromosphere and areas of abundant ionized particles in the hot outer atmosphere.

Lead author Dr. Deborah Baker (UCL Space & Climate Physics) said: "The different chemical compositions of the Sun's inner and outer layers were first noted more than 50 years ago. This discovery generated what is one of the long-standing open questions in astrophysics.