Curiosity has discovered an exciting new rock on Mars, and not just any old rock, a delicious chocolatey meteorite.
It’s not the first time the rover has found meteorites on Mars but it makes a nice change from its usual rocky scenery, and frankly, meteorites are cool on any planet. This one has been nicknamed “Cacao”.
Curiosity came across this impressive specimen while exploring Gale Crater in late January. At first, the rover’s team back home on planet Earth wasn’t sure if it was definitely a meteorite.
“The rock we are parked in front of is one of several very dark-colored blocks in this area which seem to have come from elsewhere, and we are calling ‘foreign stones,’” Ashley Stroupe, Mission Operations Engineer at NASA's Jet Propulsion Laboratory, wrote in a mission update on January 27, sharing the black and white image below.
“Our investigations will help determine if this is a block from elsewhere on Mars that just has been weathered in an interesting way or if it is a meteorite.”
A closer investigation revealed that the dark gray rock is indeed an iron-nickel meteorite about 30 centimeters (11.8 inches) across found in what NASA called a “sulfate-bearing unit” – meaning rich with salty minerals – region of Mount Sharp.
Unfortunately, the rover team explained in the Twitter thread, there's no way to date the meteorite, but "it could have been here for millions of years!" When asked about the lack of visible impact crater the team explained there probably had been a "BIG" crater in the ancient past, but erosion had flattened the area surrounding it, carving away the softer material and only leaving the hardest.
In December 2021, InSight (RIP) actually caught a meteor as it slammed into Mars, marking the first time seismic surface waves have been observed on another planet and revealing new details about Mars's interior.
Currently, the team is examining two scientific targets, named "Curare" and "Cururu", which are both on top of the Cacao rock. "This is a very tricky set of observations because Cacao is close in front of us and very tall, so we need to be extra careful to avoid hitting it with the [rover's] arm," Stroupe wrote. After that, Curiosity will attempt to drive over it to get to its next target because, for a busy rover, there are always more rocks to see.