Shakin' Goin' On?

Researchers using photographs taken by orbiting probes suggest both Mars and Earth's Moon may still be seismically active.

A group studying Mars have found trails made by boulders rolling down cliffs-- and the trails seem to radiate from what would be the epicenter of a marsquake. The fact that the trails are still obvious suggests they were made recently.

Another group, studying the Moon, has also found evidence of recent moonquakes. Grabens, long trenches across the surface associated with seismic activity, have been photographed on the far side. Of course, Apollo instrument packages have monitored moonquakes, but the newly created grabens add another line of evidence that the Moon may still be active.