The Moon could have experienced very recent tectonic activity, within the last 50 million years, reports a study published online this week in Nature Geoscience. Previously, the youngest tectonic features, much less than a billion years old, were thought to be formed by recent shrinking of the Moon as its interior cooled. Thomas Watters and colleagues analysed images obtained by the Lunar Reconnaissance Orbiter Camera. They identified narrow trough-like features in the lunar highlands and mare basalts that are thought to have formed as the lunar crust was stretched and extended. The features appear pristine and are rarely cross-cut by impact craters implying they formed relatively recently. Thermal models of lunar evolution suggest that the surface of the Moon should currently be under compression. However, the faults identified here are indications of the extension of the Moon’s surface, and imply that the Moon may not have totally melted after its formation.