The Mars Exploration Program
| Science Overview
| Technology Overview
Since our first close-up picture of Mars in 1965, spacecraft voyages to the Red Planet have revealed a world strangely familiar, yet different enough to challenge our perceptions of what makes a planet work. Every time we feel close to understanding Mars, new discoveries send us straight back to the drawing board to revise existing theories.
Image left: Mariner 4 flew past Mars on July 14, 1965, collecting the first close-up photographs of another planet.
Image credit: NASA/JPL
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You'd think Mars would be easier to understand. Like Earth, Mars has polar ice caps and clouds in its atmosphere, seasonal weather patterns, volcanoes, canyons and other recognizable features. However, conditions on Mars vary wildly from what we know on our own planet.
Over the past three decades, spacecraft have shown us that Mars is rocky, cold, and sterile beneath its hazy, pink sky. We've discovered that today's Martian wasteland hints at a formerly volatile world where volcanoes once raged, meteors plowed deep craters, and flash floods rushed over the land. And Mars continues to throw out new enticements with each landing or orbital pass made by our spacecraft.
The Defining Question for Mars Exploration: Life on Mars?
Among our discoveries about Mars, one stands out above all others: the possible presence of liquid water on Mars, either in its ancient past or preserved in the subsurface today. Water is key because almost everywhere we find water on Earth, we find life. If Mars once had liquid water, or still does today, it's compelling to ask whether any microscopic life forms could have developed on its surface. Is there any evidence of life in the planet's past? If so, could any of these tiny living creatures still exist today? Imagine how exciting it would be to answer, "Yes!!"
Image right: Mars Exploration Rover Spirit panorama near "Husband Hill."
Image credit: NASA/JPL/Cornell
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Even if Mars is devoid of past or present life, however, there's still much excitement on the horizon. We ourselves might become the "life on Mars" should humans choose to travel there one day. Meanwhile, we still have a lot to learn about this amazing planet and its extreme environments.
Our Exploration Strategy: Follow the Water!
To discover the possibilities for life on Mars--past, present or our own in the future--the Mars Program has developed an exploration strategy known as "Follow the Water."
Image left: Artist's concept of future Mars outpost.
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Following the water begins with an understanding of the current environment on Mars. We want to explore observed features like dry riverbeds, ice in the polar caps and rock types that only form when water is present. We want to look for hot springs, hydrothermal vents or subsurface water reserves. We want to understand if ancient Mars once held a vast ocean in the northern hemisphere as some scientists believe and how Mars may have transitioned from a more watery environment to the dry and dusty climate it has today. Searching for these answers means delving into the planet's geologic and climate history to find out how, when and why Mars underwent dramatic changes to become the forbidding, yet promising, planet we observe today.
To pursue these goals, all of our future missions will be driven by rigorous scientific questions that will continuously evolve as we make new discoveries.
Brand new technologies will enable us to explore Mars in ways we never have before, resulting in higher-resolution images, precision landings, longer-ranging surface mobility and even the return of Martian soil and rock samples for studies in laboratories here on Earth.