This is a historic moment - for the first time ever, a probe has seen the solar system's innermost planet from orbit, and this is the photo it took just a few short hours ago.
This is the first of 364 photos that NASA's MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry and Ranging - probe took this morning starting at 5:20 AM Eastern time. You'll want to expand the photo to get the full image.
NASA is set to release a bunch more of these images tomorrow, but for now we can see the very first product of the probe's long journey to Mercury. A project scientist explains some of the features we can see in this photo, as well as what lies ahead for the probe:
The dominant rayed crater in the upper portion of the image is Debussy. The smaller crater Matabei with its unusual dark rays is visible to the west of Debussy. The bottom portion of this image is near Mercury's south pole and includes a region of Mercury's surface not previously seen by spacecraft.
Over the next three days, MESSENGER will acquire 1185 additional images in support of MDIS commissioning-phase activities. The year-long primary science phase of the mission will begin on April 4, and the orbital observation plan calls for MDIS to acquire more than 75,000 images in support of MESSENGER's science goals.
Although Mariner 10 flew by Mercury in the 1970s and Messenger itself did some flybys of Mercury in 2008 and 2009, this is the first time ever a spacecraft has been in orbit around the planet. Humans have now put probes in orbit around most of the solar system's planets, with only Uranus and Neptune (and, yes, Pluto) left to go.