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Year of the Solar System logo: silhouette of child with planets and stars
NASA is celebrating the Year of the Solar System! Spanning a Martian year (23 months), numerous missions will encounter their targets—the Moon and Mars, Mercury and Jupiter, and even comets and asteroids! It’s an unprecedented time in planetary sciences as we learn about new worlds and make new discoveries! Join the exploration at

PLANETS: New Worlds, New Discoveries

NASA is at the leading edge of a journey of scientific discovery that promises to reveal new knowledge of our Solar System’s content, origin, evolution and the potential for life elsewhere.  NASA Planetary Science is engaged in one of the oldest of scientific pursuits: the observation and discovery of our solar system’s planetary objects.  With an exploration strategy based on progressing from flybys, to orbiting, to landing, to roving and finally to returning samples from planetary bodies, NASA advances the scientific understanding of the solar system in extraordinary ways, while pushing the limits of spacecraft and robotic engineering design and operations. Since the 1960s, NASA has broadened its reach with increasingly sophisticated missions launched to a host of nearby planets, moons, comets and asteroids.

NASA Planetary Science continues to expand our knowledge of the solar system, with spacecraft in place from the innermost planet of our Solar System to the very edge of our Sun's influence. In 2010 the EPOXI spacecraft encountered Comet Hartley 2, returning the first images clear enough for scientists to link jets of dust and gas with specific surface cometary features.  In early 2011, the Stardust-NExTmission provided the planetary science community with a first-time opportunity to compare observations of a single comet (Temple 1) made at close range during two successive passages.  When the Stardust spacecraft was retired in March 2011, it had travelled over 3.5 billion miles in our solar system. In another first, in March of 2011 NASA Planetary Science inserted the spacecraft MESSENGERinto orbit around our solar system’s innermost planet, Mercury, providing unprecedented images of that planet’s topography and improved understanding of its core and magnetic field.

Also in this unprecedented productive year of planetary exploration, the spacecraft Dawn was inserted into orbit around the asteroid Vesta in July 2011, the Juno spacecraft was launched in August 2011 on a mission to Jupiter to map the depths of Jupiter’s interior to answer questions about how the gas giant was formed; the two GRAIL spacecraft were launched to the moon in September 2011, and the Mars Science Laboratory was launched in November 2011, on its voyage to Mars with Curiosity, the largest planetary rover ever designed, destined for the surface of Mars to continue the work begun by Spirit and Opportunity. And at the outer reaches of our solar system, New Horizonscontinues on its way to study Pluto and into the Kuiper Belt, birthplace of comets.

With the release of the Planetary Science Decadal Surveyin March 2011, NASA’s planetary scientists and engineers are preparing missions to every corner of the Solar System to seek out the discoveries needed to push the boundaries of planetary science further than ever before.

Our Solar System is a place of beauty and mystery, incredible diversity, extreme environments, and continuous change. Our Solar System is also a natural laboratory, on a grand scale, within which we seek to unravel the mysteries of the universe and our place within it.