
PIXL on the rover turret
After a 203-day journey traversing 293 million miles, the Mars exploration rover Perseverance landed successfully on the surface of the red planet at 3:55 p.m. EST on February 18, much to the delight of Distinguished Professor Scott McLennan and Associate Professor Joel Hurowitz of the Department of Geosciences at Stony Brook University.
The two faculty have been working on Mars missions since 2004 and are actively involved in this mission, a two-year science investigation of Mars’ Jezero Crater. Both worked on the PIXL (Planetary Instrument for X-ray Lithochemistry) instrument that is attached to the arm of the rover. The PIXL is a micro-focus instrument that rapidly examines the chemical makeup of Martian rocks by focusing an X-ray beam to a tiny spot on the target rock or soil, analyzing the induced X-ray fluorescence.

Distinguished Professor Scott McLennan
McLennan is also a member of the SuperCam instrument team and the mission’s Returned Sample Science Working Group that will coordinate the selection of samples that will be drilled, placed into sealed containers, and cached on the Martian surface for potential future return to Earth, as part of the multi-mission international Mars Sample Return campaign.
Perseverance launched July 30, 2020, from Cape Canaveral Space Force Station in Florida. The rover mission marks an ambitious first step in the effort to collect Mars samples and return them to Earth. According to NASA, the rover will investigate the rock and sediment of Jezero’s ancient lakebed and river delta to characterize the region’s geology and past climate. A fundamental part of its mission is astrobiology, including the search for signs of ancient microbial life.
“Results obtained from the rover will address many of the highest priority scientific questions about Mars, including whether or not life ever existed on the red planet and why the climate of Mars dramatically changed during the planet’s geological history,” said McLennan. “In addition, the ultimate return of carefully selected samples by future missions will provide unparalleled opportunities for studying Mars by applying the most sophisticated scientific analyses available in the world’s finest laboratories.”

Associate Professor Joel Hurowitz
“The primary target for us is a stack of sedimentary rock that was deposited in the lake bed roughly three and a half billion years ago,” said Hurowitz, who serves as the deputy principal investigator for the PIXL and is part of the scientific leadership of the mission. “We’re going to be studying each one of those layers one by one because each contains a record or a snapshot of the environment on Mars through time. We’re hoping that it also contains some fossilized remnants that may tell us whether or not life started on Mars at one time in its history. It’s going to be a really exciting geological and astrobiological investigation for us.”
Jezero Crater is 28 miles wide and sits on the western edge of Isidis Planitia, a giant impact basin just north of the Martian equator. Scientists have determined that 3.5 billion years ago the crater was filled with water.
“This landing is one of those pivotal moments for NASA, the United States, and space exploration globally – when we know we are on the cusp of discovery and sharpening our pencils, so to speak, to rewrite the textbooks,” said acting NASA Administrator Steve Jurczyk. “The Mars 2020 Perseverance mission embodies our nation’s spirit of persevering even in the most challenging of situations, inspiring, and advancing science and exploration. The mission itself personifies the human ideal of persevering toward the future and will help us prepare for human exploration of the Red Planet.”
Watch the moment when Perseverance touches down on the surface of Mars: