One of the critical events that occurred in that initial hour was the unfurling of Phoenix's two solar cell arrays. Without the power supplied by these arrays, Phoenix would quickly drain its small batteries, and would die an ignomious death on the northern plains of Mars. Electronics on the lander detected that the batteries were charging, and a series of photos verified the good news: the arrays deployed without incident. This was the pattern for every element of the surface initiation sequence – everything operated perfectly.
On NASA TV, one could hear some of the project team members discussing the landing events. It was obvious that they were marveling at how smoothly everything had gone. Several of them commented that the actual landing was so much better than their endless simulated landings that it almost didn't seem real...
Here are the first quick photos (and mosaics) of the surrounding terrain. These initial photos are in black-and-white, but later photos will be taken through multiple color filters for many reasons, including to produce true-color photos.
Finally, here's the first stereoscopic pair from the mission. If your screen is wide enough, they will show up side by side. Then if you can cross your eyes to fuse the two images into one, you'll see a beautiul 3-D view of the Martian landscape. The pattern of gentle bumps, in polygon shape, is strongly reminiscent of certain arctic territories here on Earth. Here such shapes are caused by repeated thawing and freezing of wet soil – naturally it's very tempting to immediately conclude that's the situation on Mars. Certainly that's the suspicion, because that suspicion is why NASA chose this site for Phoenix.
Update 9:10PM:
The first post-landing news conference is underway. No surprises yet. It's fun to see this very happy team sharing their enthusiasm and joy...