The 3rd landing site workshop for the 2020 Mars Rover mission was held at the Doubletree Hotel, Monrovia, CA, on February 8-10, 2017. The primary goal of the third workshop was to further evaluate the eight candidate landing sites that emerged from the second workshop and reduce the number of candidate sites remaining under consideration to three or four. Evaluations at the workshop employed the framework provided by existing data for Mars (e.g., MRO), the science requirements of the 2020 mission, and a better understanding of the 2020 engineering requirements and traversability of the landing sites relative to these requirements. Three sites were selected to continue as landing site candidates: Jezero Crater, NE Syrtis, and Columbia Hills. The letter describing the process and results of the workshop, sent from the Mars 2020 Landing Site Steering Committee Co-Chairs (John Grant and Matt Golombek) to the NASA Mars Lead Scientist (Michael Meyer), can be found here. The letter describing the Mars 2020 project’s revised list of candidate landing sites for the mission, sent from the 2020 Mars Project Scientists (Ken Farley and Ken Williford) to the NASA Mars Lead Scientist (Michael Meyer), can be found here. For more information about the three remaining landing site candidates, please see workshop presentations and this brief overview.

The agenda for the 3rd landing site workshop, with presentation files, can be found at the meeting page (i.e., see left menu bar: 3rd workshop). Additional information on the science criteria of the eight candidate sites can be found on the Background page (see left bar), as well as information about the down-selection process. See prior meeting pages to view presentations from those meetings, including science presentations and information about how the 2020 engineering constraints relate to these eight (and other) candidate 2020 landing sites.

From the 2nd (2015) Landing Site Workshop:
The purpose of this letter is to summarize the outcome of the joint Mars 2020 Project, Mars 2020 Project Science Group, Mars Exploration Program, and Mars 2020 Landing Site Steering Committee meeting held in Monrovia, CA, on the afternoon of August 6, 2015. This meeting was held immediately following the 2nd Mars 2020 Landing Site Workshop, also held in Monrovia, CA, on August 4-6, 2015.

The purpose of the post-landing site workshop joint meeting was to discuss the Mars 2020 landing site inputs from the science community and select eight sites for further engineering and science evaluation ahead of the next planned landing site workshop, scheduled for January 2017. The eight sites selected are (in alphabetical order):

  • Columbia Hills/Gusev
  • Eberswalde
  • Holden
  • Jezero
  • Mawrth
  • NE Syrtis
  • Nili Fossae
  • SW Melas
These sites are also shown on the map in Figure 1.

Of the eight sites selected for further investigation, there is only one difference versus the landing site rankings based on scientific criteria produced at the landing site workshop: the Nili Carbonate site was not selected. Instead, the 9th ranked site from the landing site workshop was selected.

Nili Carbonate was not selected for further work due to a high risk engineering assessment and scientific overlap with other selected sites. The engineering viability of the Nili Carbonate site depends on a significant reduction in landing ellipse margin that may not be realizable. Removing the site allows conservation of limited project resources for sites that are more likely to be acceptable from a landing safety perspective. Additionally, the carbonate science and geological context are available at other sites selected for further investigation.

Preliminary engineering analyses show that Terrain Relative Navigation (TRN) is required to guarantee access to most of the top eight sites. Only one appears to be a guaranteed non-TRN site (Nili Fossae), while two others may or not may be accessible safely without TRN (Columbia Hills, Holden). Half of the top-ranked landing sites are deltaic environments (Eberswalde, Holden, Jezero, SW Melas) reflecting the strong belief in the science community that rocks in deltas are amongst the most favorable for recording signatures of possible ancient life; landing at any of these sites is expected to require TRN.

Please let us know if you have any questions related to the outcome of the joint meeting. We look forward to further developing the engineering and science cases for the selected landing sites as we prepare for the third landing site workshop in 2017.

Ken Farley
Mars 2020 Project Scientist
Ken Williford
Mars 2020 Deputy Project Scientist
John Grant
Co-Chair, Mars 2020 Landing Site Steering Committee
Matt Golombek
Co-Chair, Mars 2020 Landing Site Steering Committee
Allen Chen
Mars 2020 Landing Site Selection Coordinator


Landing Site Workshop: John Grant (, Matthew Golombek (