Vision and Voyages for Planetary Science in the - Solar System ...

live there now?”—both key components of Mars’s scientific exploration. The Workings of the Solar
System theme includes the question “can understanding the roles of physics, chemistry, geology, and
dynamics in driving planetary atmospheres and climates lead to a better understanding of climate change
on Earth?” Mars’s climate has transpired from an early, warm, wet environment to its current state of a
cold, dry planet with a thin atmosphere; its study can shed light on the evolution, and perhaps future, of
Earth’s own climate. Most like Earth in its atmosphere, climate, geology, and surface environment, Mars
plays a central role in the broad question as to “how have the myriad chemical and physical processes that
shaped the solar system operated, interacted, and evolved over time?”
SCIENCE GOALS FOR THE STUDY OF MARS
The Mars science community, through MEPAG, has worked to establish consensus priorities for
the future scientific exploration of Mars. 3 One overarching theme is to understand whether life arose in
the past and persisted to the present within the context of a differentiated rocky planet (deep interior,
crust, and atmosphere) that has been strongly influenced by its interior evolution, solar evolution and
orbital dynamics. Parallel investigations among multiple disciplines are required to understand how
habitable environments and life might have developed on a dynamic planet where materials and processes
have been closely coupled. The Mars science goals embrace this approach by articulating an
interdisciplinary research program that drives a multi-decadal campaign of Mars missions. These goals
include multiple objectives that embody the strategies and milestones needed to understand an early wet
Mars, a transitional Mars, and the more recent and modern frozen, dry Mars. Ultimately these efforts will
create a context of knowledge for understanding whether martian environments ever sustained habitable
conditions and life.
Building on the work of MEPAG, the committee has established three high priority science goals
for the exploration of Mars in the coming decade. These goals are:
• Determine If Life Ever Arose on Mars—Does life exist, or did it exist, elsewhere in the
universe? This is perhaps one of the most compelling questions in science, and Mars is the most
promising and accessible place to begin to begin the search. If successful it will be important to know
where and for how long life evolved, and how the development of life relates to the planet’s evolution.
• Understand the Processes and History of Climate—Climate and atmospheric studies remain a
major objective of Mars exploration. They are key to understanding how the planet may have been suited
for life and how major parts of the surface have been shaped. In addition, studying Mars’s atmosphere
and the evolution of its climate at various timescales is directly relevant for our understanding of the past,
present, and future climate of Earth. Finally, characterizing Mars’s environment is also necessary for the
safe implementation of future robotic and human spacecraft missions.
• Determine the Evolution of the Surface and Interior. Insight into the composition, structure,
and history of Mars is fundamental to understanding the solar system as a whole, as well as providing
context for the history and processes of our own planet. Geological and geophysical investigations will
shed light on critical environmental aspects such as heat flow, loss of a global magnetic field, pathways of
water-rock interaction, and sources and cycling of volatiles including water and carbon species (e.g.
carbon dioxide and hydrocarbons). In contrast to Earth, Mars appears to have a rich and accessible
geological record of the igneous, sedimentary, and cratering processes that occurred during the early solar
system history. Geophysical measurements of Mars’s interior structure and heat flow, together with
detailed mineralogic, elemental, and isotopic data from a diverse suite of martian geological samples, are
essential for determining the chemical and physical processes that have operated through time on this
evolving, Earth-like planet.
Subsequent sections examine each of these goals in turn.
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