I'll admit the delay of the Mars Science Laboratory to launch in 2011 depressed me. But Kepler has started to show results and that will only accelerate in 2011.

As far as planetary exploration, 2011 will usher in some incredibly exciting robotic exploration. First MESSENGER will start very serious exploration of Mercury after orbit insertion. The flybys were nice, but settling in to really start to get a handle on Mercury will be really cool. Does anyone have doubts that many new discoveries will come from this exploration?

But I have to admit, I think just about the most exciting mission out there to me is DAWN. I've been anticipating this craft's vesta arrival since launch and now there is less than a year to go. The DAWN encounter(and leisurely orbit) with Vesta planetlet really sparks my imagination. And when done with Vesta on to the dwarf planet Ceres! Whole new mini worlds to explore!

And while we are getting used to seeing these new worlds up close, the most advanced lander ever devised by man will launch in 2011 and start Mars exploration in 2012. It will be continuous Christmas for space hobbyists and planetary scientists as these new vistas and worlds are unveiled.

March 18, 2011 MESSENGER: Mercury Orbit Insertion
August, 2011 DAWN: Vesta arrival
Late 2011 Launch MSL: Landing

I'm sure I'm leaving off some other activities in 2011, but these certainly have my attention. Feel free to add more.

Not for a moment. MESSENGER has already shed light on a variety of processes going on at Mercury and has already revealed a whole new Mercury. I'm looking forward with excitement to the MESSENGER orbit insertion.

You need to add Stardust-NEXT in there, Akatsuki arrives this December and the Juno launch is before MSL's.

I'll be interested to see what Messenger can tell us about the putative ice at Mercury's poles. A recent Icarus paper by Harmon, Slade and Rice updated and improved on former Arecibo radar imaging and seems to confirm ice at both poles - indeed ice (in some cases covered by a lag) filling basically every available (shaded) spot - all the way down to 67degrees latitude in one case. There seems to be a preference for ice in shaded southern rims and at the 'cold longitudinal poles'. They suggest an icy area of around 14,000sqkm at the better imaged North pole.

Obviously the interior of these craters is dark - but will Messenger be able to image ice using light reflected from nearby crater walls?

P

..following up on Antipode’s post (and pardon me for not wanting to start a new thread), the night sky of Mercury would occasionally feature a -7 magnitude Venus at close oppositions… About 15 times brighter than our view (I have seen Venus cast a shadow on a dark night here in the northern Midwest).

…Perhaps enough light to enable some cool Messenger night photo ops (although imaging ice in a crater at even 67° would be a stretch)

Everyone forgot about Phobos-Grunt launch (November 2011). I have great expectations for this mission.

Don't forget GRAIL and Lightsail-1