After drilling two new samples last month, the rover has finally confirmed high amounts of clay minerals, providing further proof that ancient Mars was once much wetter.

The presence of clay in the area was detected by the Mars Reconnaissance Orbiter (MRO) years before Curiosity ever touched down – in fact, it was one of the deciding factors in choosing a landing site. That's because clay usually forms in water, adding to the growing body of evidence that Mars was once covered in rivers, lakes and even oceans. And where there was water, there could have been life.

Beginning on April 6, Curiosity drilled two samples (nicknamed Aberlady and Kilmarie) from the suspected clay-rich region, and immediately got some feedback that it had hit pay-dirt. The drill reportedly sliced through the soft material far more easily than it ever has before, making it the mission's first sample to be obtained through only rotation of the drill bit.