How Hydrogen and Magma Create Water Deep Inside Planets
Sub-Neptunes — worlds slightly smaller than Neptune — are common among exoplanets. They are detected using the transit method (by the dimming of a star), pioneered by William Borucki.
Nitrogen on the Brink of a Polymer: Two New Phases
Nitrogen, the very gas we breathe, behaves like a finicky metal under a million atmospheres of pressure. In a diamond anvil cell, it is squeezed to 78–98 gigapascals and heated with a laser to 1800–2500 kelvin. Under these conditions, N₂ molecules rearrange into crystals that can store energy more densely than explosives.