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Learn More about Mars Analogs:

What is a Mars Analog?

photo of MarsMars is an intriguing planet.  Data from the Mars Exploration Rovers and orbiters, such as Mars Odyssey and Mars Global Surveyor, have confirmed evidence of liquid water in Mars’ past.  Mars may have been, in some ways, similar to ancient Earth, and this is very interesting to scientists.  Even more significant is the possibility that Mars may have had (and might still have) life.  Wherever we find water on Earth, we find life!  Could the same be true for Mars?  Searching for life on Mars is a driving force behind our fascination and dedication to exploring the red planet.

Today, the environment on the surface of Mars is harsh and hostile.  The atmosphere is very thin and is only about 1/100th the air pressure on Earth.  Mars lacks a global magnetic field and when combined with its lack of a dense atmosphere, the surface (and any possible life, including human explorers) is exposed to extreme ultraviolet and space radiation.  If liquid water exists, it is probably sparse and seasonal.  Nonetheless, humans have sent more robotic spacecraft to Mars than any other planet, and NASA is planning to have human explorers on its surface within the next few decades.

photo of gullies on Marsphoto of gullies at LassenBut in the meantime, scientists are busy at work studying features of Mars—on Earth.  For example, there are places on our planet that can serve as test beds for how to conduct scientific investigations on Mars.  Antarctica, Lassen Volcanic National Park, Licancabur Volcano, and Devon Island HMP are but a few of the many places scientists are researching to help practice missions for robotic and human explorers to Mars.  These analogs share certain characteristics similar to environments on Mars.  For instance, the permanent snow packs found in Lassen Volcanic National Park are, in some ways, akin to permanent snow packs and gullies found in Martian craters and at the poles.

Jennifer studying snow algae

By studying the dynamics of snow packs on Earth, scientists can improve the models they have created to predict and analyze snow packs on Mars.  Additionally, snow algae living in the Earthly snow may give hints about how to identify life in Martian snow.

The majority of these analogs are considered extreme environments—places too harsh for humans and most other organisms, but where certain creatures like microbes thrive.  Extreme environments include such exciting places as volcanoes, deep underground, hydrothermal sea vents, glaciers, and the bottoms of permanently ice-covered Antarctic lakes.  As scientists learn more about how these microbes (called extremophiles) survive, they can use that knowledge to focus their search for life on Mars.


microbes that live in very acidic conditions extremophile that lives in water ice

scientists and engineers testing a rover




Mars analogs are also useful for trying out technology.  The Mars Exploration Rovers were tested extensively on “Mars yards”—places on Earth that have terrain like Mars.  

When astronauts get to Mars, they will need robotic helpers known as mobile agents, and Mars analogs on Earth are used to “train” these robot sidekicks. 


modbile agent with crew in Utah desert

artists conception of a drill on Mars Drilling in Rio tinto

Martian drills are being prototyped and tested in the Atacama Desert, Chile, and Rio Tinto, Spain.  The lessons learned from these drill tests on Earth are directly applied to modifying and improving the drill design for its ultimate mission to Mars.


Even human exploration of Mars is being tested on Earth.  Diverse groups of engineers, scientists, students, and psychologists have set up mock Martian habitats in places like Hanksville, Utah and Devon Island in the Arctic. 


In these studies, crews of people live in a confined spacecraft-like environment, conduct scientific research, use robots, perform extravehicular activities in mock spacesuits, plan and schedule their work with support from scientists and engineers on Earth, analyze their data and write daily reports to be inform Earth support teams of their progress; just like Martian explorers will someday.  As their work is conducted, their actions are recorded and their experience is analyzed, providing useful information to refine crew operations and mission designs.

Images credit: Mars Society
crew two at the mars desert research station mars mission simulation in the Utah desert

Studying aspects of Mars using Earth is much safer, more accessible, and less expensive.  Plus, it can be a lot of fun!  The knowledge and expertise gathered from these analog studies are an important and necessary step towards our future exploration of Mars.

See additional Mars analog studies around the world

 FirstGov  NASA

NASA Official: Mark León
Last Updated: May 2005
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