Frequently Asked Questions

So you have a question? This is the place to start. You can read all the frequently asked questions, or you can make finding your question easier by using the search fields below. If you don't see your question listed, please feel free to email Tim Titus at


Does ice have a discrete liquid stage on Mars?
Mars has a very low atmospheric pressure. Because of this, all ice can begin to boil even when the temperature is extremely low. As such, most ice sublimates on Mars.
How does Mars ice form?
The dry ice forms the same way frost forms on Earth, the ice condenses out of the atmosphere onto the soil.
How long is a Mars year?
The Mars year is not at all the 365 Earth days that our year is, rather it is 687 Earth days. To keep track of where in the year Mars is, we use Solar Longitude (Ls).
What is a seasonal freeze out?
Condensation (freezing) of the CO2 and H2O from the atmosphere.
What is Solar Longitude?
This is how we track where in orbit / seasons Mars is. See the glossary for more details on Ls.
What kinds of ice are there on Mars?
Mars ice can be categorized into two categories, CO2 ice, and H2O ice.
When is ice present on Mars?
It largely depends on where you are asking about, and what type of ice. CO2 ice is mostly found when during the winter at the large polar caps. Water ice is also largely present year round.
Where can ice be found?
Ice is found at the Martian poles. During the winter season, the polar caps extend closer to the equator.
Where can the CO2 ice be found?
95% of the Martian atmosphere is CO2. During the winter season, 25% of the atmosphere freezes out to cover 50° to 90° of latitude on the winter hemisphere.
Where can the dirty ice be found?
Dirty ice, or more appropriately, icy dirt, is found in the top meter of permafrost that is poleward of 60°
Where can the water ice be found?
Water ice can be found at the poles year round. However, at most times, it is covered with dry ice. Water ice can also be found in the top meter of soil poleward of 60°.
Where does the stuff for the ice come from?
Mars' atmosphere is largely CO2, on the order of 95% of it is. This provides an abundance for dry ice to form in a similar fashion to frost on Earth.
Where is the research happening?
Though Mars ice research is happening all over the world, much of it is conducted at following institutions: Ames Research Center, California Institute of Technology, Jet Propulsion Laboratory, Laboratoire de Météorologie Dynamique, New Mexico State Univ, Oregon State Univ, Paris-Sud Univ, Univ of Arizona, Univ of Toledo, and USGS in Flagstaff, Arizona, among many other research facilities world wide.