
Copernical Team
Magnetic waves explain mystery of Sun's outer layer

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.
Earth from Space: Sardinia

This week's edition of the Earth from Space programme features a Copernicus Sentinel-2 image of Sardinia, the second-largest island in the Mediterranean Sea.
See also Sardinia, Italy to download the image.
Sardinia, Italy

Iodine thruster could slow space junk accumulation

For the first time ever, a telecommunications satellite has used an iodine propellant to change its orbit around Earth.
The small but potentially disruptive innovation could help to clear the skies of space junk, by enabling tiny satellites to self-destruct cheaply and easily at the end of their missions, by steering themselves into the atmosphere where they would burn up.
Counting elephants from space

China's space tracking ship completes satellite launch monitoring

Using ancient fossils and gravitational-wave science to predict earth's future

3D printing to pave the way for Moon colonization

European Commission awards launch contracts for next generation of Galileo satellites

China's first solar probe to be lofted in 2022
