For the past month, the Perseverance rover has spent much of its time documenting the flights of the Ingenuity helicopter on Mars. In between those events, the rover has also been taking in the local view and spied a multitude of intriguing rocks.
Now, Perseverance is gearing up to conduct its primary mission: studying Jezero Crater and searching for signs of ancient life on Mars.
About 3.9 billion years ago, the crater was filled with a lake that was fed by a river delta. Now, rocks strewn across the dry lake bed could help scientists reconstruct the history of this area on Mars and determine whether life ever existed there.
Information locked inside the rocks could reveal more about when the lake formed and dried up, as well as at what point sediment from the delta began piling up. Creating a timeline that corresponds with the rocks will help researchers date rock samples that the rover collects over the next two years. These samples, which will be returned to Earth by future missions, could contain microfossils preserving the presence of ancient life.
Recent images taken by the rover show rocks and pebbles scattered across the crater floor, as well as a hill called Santa Cruz located about 1.5 miles (2.4 kilometers) away from the rover.
Jezero is about 28 miles (45 kilometers) wide and located north of the Martian equator. The spot is 2,300 miles (3,700 kilometers) from Curiosity's landing site in Gale Crater.
Rover's SuperCam investigates rocks
The rover is outfitted with cameras and instruments that help with its rock investigations, including SuperCam, a laser instrument that has already zapped some of rocks to determine their chemical composition.
Determining the types of rocks in this area is key. If they are sedimentary, like sandstone, they likely formed around water and could contain minerals and sand, silt or clay that preserves signs of past life called biosignatures.
Igneous rocks, which are formed by volcanic activity, provide an accurate picture of when they formed, acting like time stamps.
These rocks have been exposed to wind and radiation over time and covered with layers of sand and dust. In the field, a geologist would crack open a rock to learn more about it.
"When you look inside a rock, that's where you see the story," said Ken Farley, Perseverance's project scientist at the California Institute of Technology, in a statement.
Perseverance can't quite take a hammer to the rocks around it, but it does have a tool called an abrader on its robotic arm that can grind and flatten the surface of rocks.
Instruments on the rover can then peer inside the rock to learn more about the chemicals and minerals contained within it.
"The more rocks you look at, the more you know," Farley said.
And the more the team knows, the better samples they can ultimately collect with the drill on the rover's arm.
Answers in mudstones?
Perseverance, which landed on Mars February 18, discovered the wealth of rocks nearby while helping the Ingenuity helicopter find its first airfield. The helicopter has graduated to a new phase during which it will demonstrate its capabilities over the next 30 days, flying to new airfields and acting like a scout, without interfering with the rover's scientific operations.
Perseverance will spend the next couple hundred sols, or Martian days, exploring a 1.24-mile (2-kilometer) patch of Jezero Crater's floor. Members of the rover's science team believe they will find some of the oldest material on the red planet in the crater.
"These rocks are likely to be mudstones, once mud at the bottom of the lake, and these are very important for our investigation because this is the kind of environment that we expect to be most habitable by organisms that might have existed on Mars billions of years ago, as well as having the capability to preserve biosignatures over the billions of years since," Farley said.
The rover will collect three or four samples in the area before heading northwest toward the ancient, dry river delta.
Before this collection can begin, Perseverance needs to go through some more checks to prepare its sampling system and driving capabilities. The team estimates Perseverance will collect its first sample in July, said Jennifer Trosper, Perseverance rover deputy project manager at JPL.
Ingenuity will wrap up flight operations no later than the end of August, which will allow the rover team to conclude their science activities and prepare for a communications blackout between Mars and Earth in mid-October, when the two planets are on opposite sides of the sun.