Planetary Geology & EarthCache Sites

Help the Geocaching community learn more about our solar system, right here on Earth.

To celebrate the landing of NASA’s Rover Perseverance, which is trackable at, Geocaching HQ and GSA encourage the community to develop and visit EarthCaches that highlight planetary geology and Mars analogs found here on Earth. To better understand objects in space, such as planets, moons, asteroids, and comets, planetary geologists often study Earth-based sites, called analogs—and you can too!

A rocky Mars landscape.

View Toward 'Vera Rubin Ridge' on Mount Sharp, Mars. Image: NASA.

This early 2017 look ahead from the Mastcam of NASA's Curiosity Mars rover includes four geological layers to be examined by the mission, and higher reaches of Mount Sharp beyond the planned study area. "Vera Rubin Ridge" sits just above the reddish foreground rocks of the Murray formation.

How to Get Involved

Check out a few planetary geology EarthCache examples.

Odessa or Mars?
San Gabriel Anorthosite

Create (or update) an EarthCache that makes strong, specific, and educational connections between geologic features on Earth and Mars.

Follow the instructions in the Help Center (4.6. Planetary geology on earth).

Use some of the scientific resources compiled by GSA to aid in your background research.

Share your EarthCache with the community by doing any/all of the following:

  • Title your EarthCache in this format: “Planetary Geology on Earth: _____” (If you are updating an existing EarthCache, you may need to shorten the title to fit the character limits in
  • Post it to the Mars/EarthCache thread in the forums .
  • Share it on social media with the hashtag #geocachingtomars.

Visit EarthCaches that make Earth-Mars connections.

See the list of all related Earthcaches using Geocaching HQ‘s dynamic search.

Explore Mars some more.

NASA’s Rover Perseverance is trackable at Have you been able to discover it yet? – Mars Observing Guide

Zooniverse – Planet Four – Help explore the surface and weather of Mars' south polar region.

Zooniverse – Planet Four: Ridges – Help explore Mars by discovering networks of polygonal ridges.

Aerial photo of Martian sands.
The Red Planet's Holden Crater: Exquisite layering is revealed emerging from the sand in southern Holden Crater. Sequences like these offer a window into Mars' complicated geologic history. Image: NASA.