July 28, 2021

“Once Under 100 Meters of Water” –JPL’s Perseverance Mars Report: Heading South to Explore Jezero Crater’s Lake Bed

Crater Lake

On June 1, says the JPL, NASA’s Perseverance Mars rover kicked off the science phase of its mission by leaving the “Octavia E. Butler” landing site. Until recently, the rover has been undergoing systems tests, or commissioning, and supporting the Ingenuity Mars Helicopter’s month of flight tests.

Jezero Crater Prelude –The Flyover

The Jezero crater Octavia E. Butler” “ landing site is home to the remains of an ancient river delta. Researchers have now found deposits of hydrated silica, a mineral that’s especially good at preserving microfossils and other signs of past life, near the delta.

“Using a technique we developed that helps us find rare, hard-to-detect mineral phases in data taken from orbiting spacecraft, we found two outcrops of hydrated silica within Jezero crater,” said planetary scientist Jesse Tarnas at Brown University. “We know from Earth that this mineral phase is exceptional at preserving microfossils and other biosignatures, so that makes these outcrops exciting targets for the rover to explore.”

“The material that forms the bottom layer of a delta is sometimes the most productive in terms of preserving biosignatures,” said Jack Mustard, a professor of Earth, Environmental, and Planetary Sciences at Brown. “So if you can find that bottomset layer, and that layer has a lot of silica in it, that’s a double bonus.”

Surveying some of the oldest geologic features in Jezero Crater

During the first few weeks of this first science campaign, the mission team will drive to a low-lying scenic overlook from which the rover can survey some of the oldest geologic features in Jezero Crater, and they’ll bring online the final capabilities of the rover’s auto-navigation and sampling systems.

NASA’s Perseverance Mars rover used its Mastcam-Z imaging system to capture this 360-degree panorama of “Van Zyl Overlook,” where the rover was parked as the Ingenuity helicopter performed its first flights. The 2.4 billion-pixel panorama is made up of 992 individual images stitched together. The images were taken between April 15 and 26, 2021, or the 53rd and 64th Martian days, or sols, of the mission. (NASA/JPL-Caltech/ASU/MSSS)

Mars Perserverence

By the time Perseverance completed its commissioning phase on June 1, the rover had already tested its oxygen-generating MOXIE instrument and conducted the technology demonstration flights of the Ingenuity helicopter. Its cameras had taken more than 75,000 images, and its microphones had recorded the first audio soundtracks of Mars.

Mars Perserverence Route

This image looking west toward the Séítah geologic unit on Mars was taken from the height of 33 feet (10 meters) by NASA’s Ingenuity Mars helicopter during its sixth flight, on May 22, 2021.

“Hitting the Road” to gather first samples from another planet

“We are putting the rover’s commissioning phase as well as the landing site in our rearview mirror and hitting the road,” said Jennifer Trosper, Perseverance project manager at NASA’s Jet Propulsion Laboratory. “Over the next several months, Perseverance will be exploring a 1.5-square-mile [4-square-kilometer] patch of crater floor. It is from this location that the first samples from another planet will be collected for return to Earth by a future mission.”

The science goals of the mission are to study the Jezero region in order to understand the geology and past habitability of the environment in the area, and to search for signs of ancient microscopic life. The team will identify and collect the most compelling rock and sediment samples, which a future mission could retrieve and bring back to Earth for more detailed study. Perseverance will also take measurements and test technologies to support future human and robotic exploration of Mars.

Exploring two unique geologic units

Spanning hundreds of sols (or Martian days), this first science campaign will pursue all of the mission’s science goals as the rover explores two unique geologic units in which Jezero’s deepest (and most ancient) layers of exposed bedrock and other intriguing geologic features can be found. The first unit, called “the Crater Floor Fractured Rough,” is the crater-filled floor of Jezero. The adjacent unit, named “Séítah” (meaning “amidst the sand” in the Navajo language), has its fair share of Mars bedrock but is also home to ridges, layered rocks, and sand dunes.

Martian version of an old auto club-style map

“To do justice to both units in the time allotted, the team came up with the Martian version of an old auto club-style map,” said JPL’s Kevin Hand, an astrobiologist and co-lead, along with Vivian Sun, of this science campaign. “We have our route planned, complete with optional turnoffs and labeled areas of interest and potential obstructions in our path.”

Jezero Crater Map

This annotated image of Jezero Crater depicts the routes for Perseverance’s first science campaign (yellow hash marks) as well as its second (light-yellow hash marks). (NASA/JPL-Caltech/University of Arizona)

Negotiating the Sand Dunes

Most of the challenges along the way are expected to come in the form of sand dunes located within the mitten-shaped Séítah unit. To negotiate them, the rover team decided Perseverance will drive mostly either on the Crater Floor Fractured Rough or along the boundary line between it and Séítah. When the occasion calls for it, Perseverance will perform a “toe dip” into the Séítah unit, making a beeline for a specific area of interest.

Under at least 100 meters of water 3.8 billion years ago

The goal of the campaign is to establish what four locations in these units best tell the story of Jezero Crater’s early environment and geologic history. When the science team decides a location is just right, they will collect one or two samples.

“Starting with the Crater Floor Fractured Rough and Seitah geologic units allows us to start our exploration of Jezero at the very beginning,” said Hand. “This area was under at least 100 meters [328 feet] of water 3.8 billion years ago. We don’t know what stories the rocks and layered outcrops will tell us, but we’re excited to get started.”

The first science campaign will be complete when the rover returns to its landing site. At that point, Perseverance will have traveled between 1.6 and 3.1 miles (2.5 and 5 kilometers) and up to eight of Perseverance’s 43 sample tubes could be filled with Mars rock and regolith (broken rock and dust).

Delta is rich in carbonates that can preserve fossils

Next, Perseverance will travel north then west toward the location of its second science campaign: Jezero’s delta region. The delta is the fan-shaped remains of the confluence of an ancient river and a lake within Jezero Crater. The location may be especially rich in carbonates – minerals that, on Earth, can preserve fossilized signs of ancient life and can be associated with biological processes.

The Daily Galaxy via Jet Propulsion Lab (JPL)

The NASA image at the top of the page illustrates area through which the Mars 2020 Perseverance rover could traverse across Jezero Crater as it investigates several ancient environments that may have once been habitable. The route begins at the cliffs defining the base of a delta produced by a river as it flowed into a lake that once filled the crater. The path then traverses up and across the delta toward possible ancient shoreline deposits, and then climbs the 2,000-foot-high (610-meter-high) crater rim to explore the surrounding plains. About half of this traverse could be completed in Perseverance’s prime mission (one Mars year, or two Earth years). For reference, the prominent crater near the center of the image is about 0.6 miles (1 kilometer) across.

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