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International Mapping Standards Updated for Planets throughout Solar System

March 29, 2018

Clarifying Latitude and Longitude for Planets besides Earth

The internationally agreed upon standards for mapping planets and objects other than Earth throughout the solar system have been updated in a new report led by the U.S. Geological Survey. These standards include definitions of the latitude and longitude systems and body size and shape for all mapped objects.

The new parameters can be universally used by planetary science researchers to assign geographic position information to their data sets, allowing them to be registered and compared at known levels of accuracy and precision.

“These new standards ensure that anyone around the world, including individual scientists, instrument teams, spacecraft missions and space agencies, can make maps and geographically register information that can be compared and used interchangeably,” said Brent Archinal, a USGS scientist and the lead author of the study. “The recommended parameters will also allow for accurate and safe navigation of spacecraft near solar system bodies.”

Archinal is the chair of the Working Group for Cartographic Coordinates and Rotational Elements, the international group of scientists who have been given the responsibility by the International Astronomical Union to define the rotational elements of the planets, satellites, asteroids and comets of the solar system on a systematic basis. The WGCCRE issues a report approximately every three years that describes the most up-to-date recommendations for the latitude and longitude and rotational elements of all planetary bodies. The current report consolidates recommendations made at the 2015 meeting of the IAU.

These new parameters have provided a significant improvement to the coordinates on Mars. The previous model recommended by the working group had an error level of many tens of meters over 20-30 years, while the new model has a level of error at the 10-meter level over such periods. The new standards also provide a more accurate definition of the zero degrees longitude, or the prime meridian location, of Mars.

The USGS Astrogeology Science Center in Flagstaff, Arizona, has a long history of assisting the IAU with planetary cartography, as well as planetary nomenclature. The USGS Astrogeology Science Center is a national resource for the integration of planetary geoscience, cartography and remote sensing. The center was established in 1963 to provide lunar geologic mapping for NASA and assist in training astronauts destined for the moon. Throughout the years, the USGS has participated in processing and analyzing data from numerous missions to planetary bodies in our solar system, and collaborates with the planning and operation of space exploration missions.