In 1997 the Mars Global Surveyor measured elevations. So the 97 exaggeration factor commemorates 1997. The three photographs are not 97x they use 40x and 150x globe exaggeration factors. The blue "thingview" is the 97x design. The gray images are for a 386 megabyte .stl file linked in my About section. The Valles Marineras file is so big , I keep it on Google Drive. Scientists credited: S. SLAVNEY, 1999-03-10; M. CAPLINGER, 2000-04-04; R. SIMPSON, 2000-11-03; The Mars Global Surveyor (MGS) spacecraft was launched from the Cape Canaveral Air Station in Florida on 7 November 1996 aboard a Delta-2/7925 rocket. The 1062-kilogram spacecraft, built by Lockheed Martin Astronautics, traveled nearly 750 million kilometers over the course of a 300-day cruise to reach Mars on 12 September 1997 [JPLD-12088]. Upon reaching Mars, MGS fired its main rocket engine for a 25-minute Mars orbit insertion (MOI) burn. This maneuver slowed the spacecraft and allowed the planet's gravity to capture it into orbit. Initially, MGS whirled around the red planet in a highly elliptical orbit that took 45 hours to complete. Thank you NASA.Here is a link to all data that I used for Mars: http://pds-geosciences.wustl.edu/mgs/mgs-m-mola-5-megdr-l3-v1/mgsl_300x/meg004/ It has 4 files of Mars elevations, and instructions about format.