Turbulence is ubiquitous and occurs every day, such as when milk is stirred into coffee or in the stormy motions of the ocean and the atmosphere. Media in space and astrophysical systems can also develop turbulence, but the physics is different because the medium is in an ionized state (known as the plasma state) and the flow motion is strongly coupled to electromagnetic fields. Furthermore, space plasma is collisionless because the medium is so dilute that the particles do not collide with each other.

Analyzing a sample of 300 of the best-characterized planetary systems among the more than 1,000 known in the Milky Way, an international research team led by the Italian National Institute for Astrophysics (INAF) has discovered that the multiplanet systems identified so far belong to two distinct “families.”

A new study led by researchers at the University of Oulu in Finland sheds light on a poorly understood part of space weather: where powerful waves form at the edge of Earth’s magnetic shield and where the solar wind can find a way through.

The speed of an asteroid’s spin can tell astronomers a surprising amount about what it is made of. However, existing approaches to measuring spin based on telescope observations can often produce misleading estimates.

In the early moments of the big bang, two elements were forged: hydrogen and helium. Technically, the tiniest traces of light elements such as lithium were produced as well, but nothing of consequence. The early universe was about three parts hydrogen to one part helium. All the heavier elements, from the oxygen in your lungs to the iron in your blood, were created through astrophysical processes—fused in stars, formed in supernovae or scattered by the collisions of neutron stars. Even in the present cosmos, heavier elements are so cosmically rare that astronomers group them all as metals.