SCIENCE EXPLORATION SCHEME : PERSEVERANCE MASTER ESSAY.

BEYOND JEZERO : Perseverance has driven up and out of Jezero and is now exploring rocks that are some four billion years old in a region known as Lac de Charmes, after a reservoir in France.

Bedrock that old is rare on Earth, because plate tectonics and weather continually reshape the surface of the planet.

'' What Perseverance is offering us is really a view into that very early solar system history, like in the first half a billion years,'' said Vivian Sun, the acting deputy project scientist.

'' There's a lot that we can learn from these rocks.''

These rocks include the light-colored ones that have intrigued the NASA scientists since August.

Most of the Martian crust is made of basalt, a fine grained volcanic rock that is dark gray. { The reddish tint of Mars comes from the dust. When rock weathers, iron in the minerals rusts.}

'' And so anytime we see something that is distinctly light-toned, it attracts attention,'' said Katie Stack Morgan, a project scientist.

At the northern end of a valley in Lac de Charmes, the scientists spotted a collection of light-colored rocks so the rover took a detour to take a look.

The light colored rocks are what are known as  gabbros - coarse grained volcanic rocks that are similar in composition to basalt, but which probably formed farther underground where the magma cooled more slowly and allowed larger crystals to form.

'' We've been seeing in these rocks evidence for very intense melting and shock, and this is exactly what we expect to see in really, really ancient pre-Jezero rocks representing the crust of Mars,'' Dr. Stack Morgan said.

The scientists think the blocks of rock might even be the result of three separate meteor impacts - one that melted the Martian crust and produced the gabbro, a second that created patterns of  shock and additional melting and a third that propelled them to their current location just outside Jezero.

'' It's very much a detective mystery here,'' Dr. Stack Morgan said.

Perseverance attempted to drill one of the rocks, but it was too hard to collect a sample.

!WOW! thanks Kenneth Chang and The NYTs.