This story was updated 11:35 a.m. EDT.
Stern, a seasoned planetary scientist who joined NASA in April 2007 to pursue a reform-minded agenda, informed colleagues in an e-mail March 26 that he would be leaving the agency in the month ahead.
In his e-mail, which he sent out at 8:34 a.m., according to the time stamp, Stern said that he offered his resignation March 25 and that NASA Administrator Mike Griffin "reluctantly accepted" it.
"I will remain at NASA for a few weeks," Stern wrote. "It's been my privilege to serve the NASA and scientific community and to work with you."
"I also want you to know," Stern continued, "that Mike and I remain on good terms. He remains in my eyes the best administrator NASA has ever had."
In a statement,
"Alan has rendered invaluable
service to NASA as the Principal Investigator for the Pluto/New Horizons
mission, as a member of the NASA Advisory Council, and as the associate
administrator of the Science Mission Directorate,"
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