There is one less robot exploring the solar system today. MESSENGER, which has orbited Mercury for four years, finally ran out of fuel and crashed into the planet at 17:26 UT on Thursday, April 30, 2015.
At last week's Lunar and Planetary Science Conference, the MESSENGER team held a press briefing to share results from the recent few months of incredibly low-altitude flight over Mercury's surface. The mission will last only about five weeks more.
The two spacecraft currently orbiting the two innermost planets are both flying low in their orbits in the final phases of their missions. MESSENGER just performed a rocket burn to raise its orbit slightly, while Venus Express did the opposite.
Vignettes from dozens of LPSC talks: GRAIL and LADEE at the Moon; ice and craters and conglomerates and organics and gullies on Mars; polar deposits and volatile elements on Mercury; tectonics on Enceladus; and more, until my brain was so full I could barely speak.
Note the special time! In this week's Planetary Society hangout at 5pm PDT / midnight UTC, I'll talk with MESSENGER deputy principal investigator Larry Nittler about what MESSENGER has accomplished in its prime and extended missions at Mercury, and what it stands to do if awarded a mission extension.