Mars Science Laboratory Contribution to Mars Exploration Program Science Goals

Mars Science Laboratory science investigations are designed to support the Mars Exploration Program's overall science strategy of "Following the Water." The four science goals that support this strategy for discovery are:

NASA's strategy for scientific investigations on Mars is to "follow the water." Without water now or in the past, life as we know it could not exist.

The first step in understanding the possibility of past or present life on Mars is to determine whether the red planet ever had environmental conditions able to support life. Now that NASA's two Mars Exploration Rovers, Spirit and Opportunity, have found compelling evidence that liquid water once persisted on the surface of Mars, scientists hope to determine if other things necessary for life were also present. With a single rover bigger than both the Viking landers sent to Mars in the 1970s, Mars Science Laboratory will look for chemical elements that are the building blocks of life. These building blocks include six elements necessary to all life on Earth: carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.

Life requires small amounts of other elements, such as iron, along with sources of energy. On Earth, this energy comes from sunlight or from electrons moving back and forth between elements and compounds in nature. Life also requires a stable enough environment to to get a foothold without being eradicated by natural hazards such as volcanic explosions or excessive ultraviolet radiation. The Mars Science Laboratory will study carbon and water cycles on the planet through its history. That is, it will seek to determine in what form and amount carbon and water is stored on the planet or in its atmosphere and how that may have changed through time.

Scientists hope to determine if environmental conditions on Mars were ever capable of supporting microbial life. An example might be layers of rock indicating the presence of water, as portrayed in this artist's concept.

Mars Science Laboratory will characterize Mars' ancient climate and climate processes for the lower and upper atmosphere. In the past, a warmer Mars might have supported a thicker, wetter atmosphere. But now, with its thin, cold atmosphere, much of the water on Mars has left the surface and atmosphere. Most of it is probably trapped under the surface, either as ice or possibly in liquid form if any exists near a heat source on the planet, such as a volcanic "hot spring." An earlier thicker, wetter atmosphere may have provided better environmental conditions for supporting microbial life in Mars' early history.

Mars Science Laboratory will allow scientists to determine more precisely the composition of the Martian atmosphere, for instance, by measuring the stable isotopes of elements such as carbon. (Isotopes are atoms of the same element that have different masses because they have a different number of neutrons in the nucleus.) Most elements of biological interest have two or more stable isotopes. Organisms often selectively use particular isotopes based on their availability and mass. Environmental conditions also affect the availability of various isotopes. Mars Science Laboratory will look for biosignatures - signs of life - such as abrupt changes in isotopic abundance that might be associated with life, and will investigate the composition of rocks, soils, and land forms that might be linked with changes in the planet's atmosphere over time.

Mars Science Laboratory will study Martian weather patterns and characterize the distribution of water, carbon dioxide, and hydrogen in the atmosphere and near the surface. It will also measure surface radiation, including cosmic rays, solar protons, and neutrons bombarding the planet from space.

Layers of rock in craters and mountains, as shown in this artist's concept, contain a record of the geologic past on Mars.

A record of Mars' history is folded in the layers of the martian surface -- in essence, geology's version of tree rings. Mars Science Laboratory will study the rock and soil record in order to understand the geologic processes that created and modified the martian crust and surface through time. In particular, it would look for evidence of rocks that formed in the presence of water.

Mars Science Laboratory will help pave the way for potential human exploration of Mars, as depicted in this artist's concept.

By demonstrating an ability to land large, heavy payloads on the surface, Mars Science Laboratory will pave the way for sending equipment and the huge infrastructure needed by any human explorers of the future. Experience in precision landing techniques will also provide the first early steps in developing an ability to send astronauts to a given location safely and reliably.

A better understanding and characterization of radiation levels at the surface of Mars will help mission planners understand potential hazards faced by any future astronaut crews and design methods for protecting their health.