NASA’s Curiosity is exploring the slopes of Mars' Mount Sharp, the highest feature within the Gale Crater. This area was once a large lake and the rover is studying the composition of the soil to better understand how this mountain came to form, and how different Mars was billions of years ago.

One of the robotic explorer’s instruments focuses on minerals that only form in the presence of water. And a few weeks ago, it struck gold. Well, clay. It collected two samples and found the largest amount of clay minerals ever found during the mission. Curiosity has spent over 2,425 Martian days (or sols) on the Red Planet, since arriving there on August 6, 2012.

The rover drilled two target rocks, nicknamed "Aberlady" and "Kilmarie". Although they contain more clay minerals, they are poorer in hematite, an iron oxide that was common on the Vera Rubin Ridge (named after the famous American astronomer), which Curiosity previously explored and only recently left just a few months ago.

Among the hard work of collecting the new samples, Curiosity found time to take a celebratory selfie not only showing itself in its full glory but also showing the holes it left in Aberlady and Kilmarie. The selfie was taken on May 12, or sol 2,405^th, but the samples were collected back in April. The rover drilled at Aberlady on Sol 2370, and Kilmarie on Sol 2384.

It is believed that the rocks currently being studied on Mount Sharp formed from ancient layers of mud. The composition of the samples is giving researchers insights into what the region looks like. We believe water is one of the key elements for the formation of life, so it could be possible that once upon a time this region had life. So far we haven’t found any conclusive evidence that this was indeed the case.

Between drilling, analyzing samples, and taking selfies, the rover has also been working as a meteorologist. It observed drifting water ice clouds on May 7 and May 12 roughly 31 kilometers (19 miles) high. NASA’s lander InSight also, recently, observed clouds. The teams running the two missions are planning to coordinate observations. The rover and the lander are 600 kilometers (372 miles) apart so observing the same clouds would allow them to more precisely estimate their altitude.