NASA recently revealed that Chief Scientist Ellen Stofan has left the space agency after more than three years on the job to embark on “new adventures.”

Stofan was appointed NASA chief scientist on August 25, 2013, and served as the principal advisor to NASA Administrator Charles Bolden, overseeing the agency’s science portfolio.

In a recent interview for NASA’s tumblr, Stofan said she had the opportunity to work on several fun challenges such as the agency’s strategy on how to get humans to Mars as well as learning about and promoting research conducted each day on the International Space Station.

Stofan said she believes the next big thing for NASA is the search for life beyond Earth. Regardless of whether that discovery takes place on Mars, on an ocean world like Europa (one of Jupiter’s four Galilean moons) or one of the distant planets discovered by the Kepler Space Telescope outside of our solar system, Stofan believes the answer of whether or not we are alone in the universe will be answered in the next few decades.

Stofan’s departure appears to be part of a larger management reshuffling. Geoffrey Yoder, Deputy Associate Administrator for the Science Mission Directorate, announced in September that he would be retiring from the agency at the end of the year. A recent internal memo revealed that Dennis Andrucyk, the current deputy associate administrator for NASA's Space Technology Mission Directorate and acting chief technologist, would fill the vacancy left by Yoder effective January 17.

NASA spokesperson Dwayne Brown was unable to provide Space.com with an exact departure date or information as to who might fill the role of chief scientist in Stofan’s absence.