Walking towards an ancient delta
Processed image. Enhanced-colour Mastcam-Z mosaic made from 14 frames captured on 28 November 2021 (sol 275). The blue sky is a processing effect, not the colour a person would see on Mars.
NASA/JPL image-use policy · credited mission imagery, resized to WebP
· Original image source · Image licenceOrbital expectations become cliffs, layers and a route across the ground.
- World
- Mars
- Case date or period
- Image archive · 2021–2022
Look closer
Jezero’s delta changes character as the rover approaches. Distant mesas resolve into stacked layers and eroded slopes, offering a way to read sedimentary architecture from the ground.
Follow the evidence
Compare the broad panorama and closer views before choosing a single intriguing detail. Perspective, distance and the rover’s changing viewpoint all affect the apparent shape of the delta front.
Layers that distinguish a delta from dunes
Nicolas Mangold and colleagues’ 2021 study measured the geometry of layers at Kodiak, an isolated remnant south of the main fan. Inclined beds lie between near-horizontal beds, with no evidence that later faulting or slipping rotated the outcrop. The arrangement supports sediment deposited on a delta front advancing into a lake, rather than windblown dunes. Layer transitions also indicate changing water levels; they do not mean Jezero held one constant-depth lake throughout its history.
Flood deposits change the story
The same study identified unsorted cobbles and boulders embedded in upper fan deposits, rather than merely loose stones that rolled downhill. Their size and setting imply flows capable of transporting much heavier material than the earlier delta-building river. The authors infer a shift toward powerful flood episodes, but leave some relationships between debris-covered units unresolved. A flood deposit documents a transport event; it does not by itself establish the cause or duration of the wider climate change.
Sources & further reading
- Spanning the Delta of Mars' Jezero Crater — NASA Image and Video Library / JPL
- Detailed Panorama of Mars' Jezero Crater Delta — NASA Image and Video Library / JPL
- Jezero Crater's Delta Is Getting Closer — NASA Image and Video Library / JPL
- Jezero: planetary feature record — IAU / USGS Gazetteer of Planetary Nomenclature
- Perseverance rover reveals an ancient delta-lake system and flood deposits at Jezero crater, Mars — Mangold and colleagues (2021) — Science / author-hosted first-release paper
- Perseverance Captures Image of Kodiak — NASA / JPL Photojournal