CNN News:NASA公布18亿像素火星图片

It all starts now with a picture. They say pictures are worth a thousand words. These are said to have 1.8 billion pixels. And while it looks like a high resolution image of a desert landscape, maybe in Utah, it's actually the desert landscape of Mars, taken from Mars.
NASA has several active missions there. This panorama was captured by a rover named Curiosity. It's the key part of a $2.5 billion project to investigate the planet's environment. What looks like one picture according to NASA is actually made up of 1,200 individual images that were taken over several days. Scientists can zoom in to see distant details, for instance, the rim of the crater that Curiosity is in. Pan left and you can see another crater estimated to be three miles wide. An area that's rich in clay, unique features of the land, a cliff — it's all visible here. And from the details we can see of the Curiosity rover itself, a sundial is there to indicate what time of the sol it is.

Scientists call days on Mars "sols". Each ones about 39 and 1/2 minutes longer than each Earth day. You can also see the tracks the rover made through the Martian dirt as it ambled across the planet's surface. The photos were taken around the time of last Thanksgiving. While NASA's employees were off enjoying turkey, the organization made Curiosity work. That is to say it gave the rover the command to take lots of pictures that could be stitched together to complete the panorama.