Paul VoosenTwo years ago, NASA’s InSight spacecraft alighted on the surface of Mars, aiming to glean clues to the planet’s interior from the shaking of distant earthquakes and deep heat leaking from its soil.
Mars, it turned out, had other ideas. Its sticky soil has thwarted InSight’s heat probe, and in recent months howling winds have deafened its sensitive seismometers.
Most mysteriously, the planet hasn’t been rattled by the large marsquakes that could vividly illuminate its depths.Despite these hurdles, a precious clutch of small-but-clear quakes has enabled the InSight team to see hints of boundaries in the rock, tens and hundreds of kilometers below.