English: Brett W. Denevi, a scientist at the Johns Hopkins University Applied Physics Laboratory (APL) speaks during a briefing on the discoveries provided by NASA's MESSENGER spacecraft while in orbit around the planet Mercury, Thursday, June 16, 2011, at NASA Headquarters in Washington. After nearly three months in orbit about Mercury, MESSENGER's payload is providing a wealth of new information about the planet closest to the Sun. Photo Credit: (NASA/Paul E. Alers)