Frequently Asked Questions
Find answers to our most frequently asked questions below.
The goals for this website are to catalog completed geologic maps and to help track the progress of currently funded maps. If you would like to propose for a mapping investigation, check the appropriate planetary body in the map indexes on the Map Search page to see which geologic maps may have already been published or are currently in progress. Please also review our Mapping Handbook on the Guidelines page which contains general information on planetary geologic map processing from proposals to publication, suggested map content, and mapping program support personnel.
The USGS Astrogeology Science Center provides coordination of NASA's planetary geologic mapping program. Geologic mapping investigations of any imaged planetary body (except Earth) are proposed to NASA's Planetary Geology and Geophysics Program on an annual basis and then reviewed by the Lunar and Planetary Geoscience Review Panel. USGS map coordination is provided under the auspices of NASA's Planetary Cartography and Geologic Mapping Working Group and its Geologic Mapping Subcommittee. USGS provides:
- Participation in working groups charged with developing planetary geologic mapping program plans.
- Management and coordination of individual mapping projects.
- Oversight and expertise in meeting the requirements of USGS map standards.
- Editorial support in map reviews and revisions.
- Generation of geologic base maps and databases for map investigators, and
- Pre-press preparation and printing of maps in the USGS Scientific Investigations Map (SIM) Series.
Frequently Asked Questions
Where can I find information for NASA Proposers?
What is the purpose of The Planetary Geologic Mapping Program?
How are geologic mapping projects funded?
What happens when an author withdraws or relinquishes their map?
What scales are currently being mapped?
How do planetary geologic maps differ from terrestrial maps?
What is the map review process?
Can I use this website if I am not funded to produce a USGS map?
How do I get a feature named in my map region?
What is the sequence of events that leads to a geologic map?
How are map reviewers assigned?
What are the recommended digital mapping procedures?
When are mappers meetings held?
What is the difference between USGS review and technical review?
What is metadata and why should I care?
What are the typical components of a geologic map?
What is the purpose of The Planetary Geologic Mapping Program?
The purpose of the Planetary Geologic Mapping Program (PGM) is to provide the science community and general public with high-quality cartographic products that accurately represent the materials exposed on the surface of rocky bodies within the Solar System. In addition, PGM helps advise the science community by establishing techniques and guidelines for the timely and consistent production of geologic map products.
How are geologic mapping projects funded?
Geologic maps are supported by funds from various NASA programs. Individual investigators from a range of U.S. research institutions submit proposals that contain research elements appropriate for the production of scale-based geologic maps. The U.S. Geological Survey, through NASA's Planetary Geology and Geophysics Program, supports selected proposals that intend to produce scale-based geologic maps. This support includes the production of geologic base maps, relevant supplemental data sets, and geographic information system (GIS) projects and guidelines. Investigators are encouraged to contact the USGS Map Coordinator prior to submitting proposals to ensure that the desired technical specifications of intended geologic maps are wholly capable.
What happens when an author withdraws or relinquishes their map?
Maps that are withdrawn are those where past investigators have conducted some mapping but the map was never brought through the USGS review and publication process. Such maps have been officially released by past investigators so that other interested researchers can submit a mapping proposal. In some cases, the previous mapper has provided USGS with incomplete map products or components thereof that might be of use to future mappers Interested mappers should contact the USGS Map Coordinator for more information.
What scales are currently being mapped?
Three primary programs underway now are:
- 1:2,000,000-scale quadrangle mapping of the Moon using Lunar Orbiter and Clementine photomosaics
- 1:5,000,000- and 10,000,000-scale quadrangle mapping of Venus using Magellan synthetic aperture radar data
- Mapping of Mars at various scales using various image data sets including Thermal Emission Imaging System infrared and visual range, Context Camera, High Resolution Stereo Camera, and High Resolution Imaging Science Experiment images and topographic data derived from Mars Orbiter Laser Altimeter and stereophotogrammetrically derived digital elevation models.
Other planetary bodies are included in the mapping program wherever adequate mapping data are available.
How do planetary geologic maps differ from terrestrial maps?
Established cartographic standards that apply to terrestrial maps, such as map symbols, layout, scales, and quadrangle systems, are effectively replicated in most planetary geologic maps. However, the concentration on remote-based geologic observation for planetary regions of interest (versus field-based geologic observation for terrestrial regions of interest) forces us to adapt or alter some elements of cartographic representation. Most of these adaptations are intended to convey the lack of absolute knowledge about some mapped materials.
What is the map review process?
All NASA-funded (and USGS-supported) geologic maps go through an intensive process of review and revision. Mappers are expected to prepare maps in accordance with the latest guidelines in order to maintain a level of high-quality and consistency across all published maps. Each map goes through two (or more) technical reviews, a USGS/Map Coordinator review, a nomenclature review, and a metadata review (for digital submissions). The entire review and production process can last a year or more, depending on the initial state of the map and the responsiveness of author(s) to review comments.
Can I use this website if I am not funded to produce a USGS map?
Though the overarching focus of the Planetary Geologic Mapping community is to support NASA-funded projects that will result in USGS-published geologic maps, the techniques and guidelines that are provided by PGM and USGS should be used as a community resource.
How do I get a feature named in my map region?
Feature names are approved by the International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). To request a feature name for your mapping area please fill out the Name Request Form at the Gazetteer of Planetary Nomenclature website.
What is the sequence of events that leads to a geologic map?
The process from proposal to publication for geologic maps funded by NASA and published under the USGS SIM series is detailed in the Mapping Handbook on the Guidelines page. An updated version for 2022 is now available.
How are map reviewers assigned?
Technical reviewers are assigned by the Map Coordinator, with the approval of the GEMS Chair.
What are the recommended digital mapping procedures?
The vast majority of mappers now use Esri's ArcMap 10.x or ArcGIS Pro to digitally map in a GIS, and funded mappers receive a prepared GIS project for their mapping area with all relevant base maps and a geodatabase ready for use. The MRCTR GIS Lab is equipped to provide guidance on best practices, either remotely or in-person, and there are a number of online GIS tutorials to help as well.
When are mappers meetings held?
The Planetary Geologic Mappers annual meeting is held each summer, typically in early summer. Past meetings are listed on the Meetings page.
What is the difference between USGS review and technical review?
The initial USGS review conducted by the Map Coordinator is like a 'pre-review' of all submitted map components to ensure completeness and adherence to community standards. Once any necessary revisions are made the map and materials are passed on to the two assigned technical reviewers who look at the map package in its entirety, checking for accuracy, compatibility, correlation of map components, and other recommendations. Corrected map packages, with itemized responses to issues addressed during technical review, are then brought back to USGS for the Map Coordinator and nomenclature reviews.
What is metadata and why should I care?
Metadata is ancillary documentation that helps describe the rationale, authorship, attribute descriptions, spatial reference, and other pertinent information about a geospatial data set, as recommended by the Federal Geographic Data Committee (FGDC). It is commonly referred to as 'data about data'. At a minimum, proper metadata improves search, discovery, and data reuse. In short, a simple description of the data and its' intended use can help to stave-off misuse. Details of the processing steps and accuracy are often undocumented in currently released data sets. It is also important for users to recognize who created the data as well as to correctly credit or identify the origin of the data if the product is derived.
What are the typical components of a geologic map?
Components of a geologic map can vary; however, in addition to the geologic map itself all geologic maps typically contain at a minimum:
- description of map units (DOMU)
- correlation of map units (COMU)
- explanation of map symbols (EOMS)
- figures
- tables
- captions
- map text
- GIS files
After submission to USGS the relevant metadata, readme, web abstract and cover art are generated as required and packaged. Specific guidance on geologic map components can be found on the Guidelines page.
Information for NASA Proposers
Proposed geologic mapping or topical science investigations of any planetary or satellite surface that are intended to result in the publication of a Scientific Investigations Map (SIM) by the U.S. Geological Survey (USGS) should check the relevant box on the proposal Cover Page and clearly indicate this intention in the Proposal Summary, as well as in the text of the proposal. Investigators who choose to produce a geologic map as a USGS product will be required to follow current guidelines for the production and submission of digital products, including the generation of maps that are compatible with Geographic Information System (GIS) software packages for review, edit, and publication. To support this requirement, the USGS will provide a GIS project that contains the projected, geographically rectified, and scaled mapping base or mosaic as well as other relevant global- or regional-scale data sets (if available and needed). Investigators selected to publish USGS geologic maps will be expected to:
- provide peer reviews for two geologic maps generated by other planetary mappers, and
- attend the annual Planetary Geologic Mappers Meeting to present map status to the mapping community and receive updates on current guidelines.
Proposers are encouraged to contact the Map Coordinator (jskinner@usgs.gov) in order to obtain further information pertaining to the production of USGS geologic maps (e.g., map bases, scales, extents, formats, guidelines).