Extreme‐pressure research explores how Earth's mantle solidified

During the earliest stages of the Earth's formation, the planet's mantle may have taken the form of a giant magma ocean, being fully or partially molten all the way down to the core‐mantle boundary. Though mantle material is predominantly solid today, some scientists suggest that regions of anomalously low seismic wave velocity deep within the mantle, known as ultralow velocity zones (ULVZs), may be indicative of a remnant magma ocean or of partial melting of minerals near the core‐mantle boundary. To understand how the early mantle solidified or whether modern melt could be the source of ULVZs, scientists need to know how various minerals and melts behave under the extreme conditions found near the center of the Earth.