[酷图] 机遇号抓拍蓝色日落 下周将在火星上拍日食

据美联社报道，美国“机遇号”火星车在拍摄火星地平线全景画面时，幸运地拍到了火星日落的奇景——空气中的灰尘让太阳看上去是蓝色的。

6个轮子的火星车拍照并不是为了记录风景，而是为了方便科学家们研究火星大气中的灰尘特性。指挥“机遇号”火星车上的全景照相机的科学家吉姆·贝尔昨天在美国航空航天局喷气推进实验室里展示了由机遇号拍摄的照片拼接而成的影片，从影片中人们可以看到蓝色的太阳在地平线上迅速地黯淡下去，蓝色主要是灰尘散射阳光所造成的。

在下个星期，指挥火星车的小组将尝试一下人类从未做过的事情：在另一个星球表面拍摄日食。火星车的摄像装置将捕捉火星的两颗“月亮”——火卫一与火卫二运行时经过太阳表面的奇观。

中新网　2004年02月28日

PIA05343: The Sun Sets on Mars

On Sol 20 of its journey, Mars Exploration Rover Opportunity woke up around 5:30 in the martian afternoon to watch the sunset. A series of five sets of three-color images from the rover's panoramic camera was acquired looking toward the southwest. Each set used an infrared, green and violet filter, rather than the human red-green-blue, so that the maximum panoramic camera wavelength range could be covered by the observations, enhancing the scientific value of the measurements.
A color image was made from the first post-sunset sequence of calibrated color images, with the color balance set to approximate what the sunset color would have looked like to the human eye. The color seen in this first post-sunset image was then used to colorize each image in the sequence. Approximately one-minute gaps between consecutive color images meant the Sun's position changed within each color set, so the images had to be manually shifted to compensate for this motion. In this fashion, the position and brightness of the Sun are taken from each individual image, but the color is taken from a single set of images. The images were then combined into a movie where one color set fades gracefully into the next. Analysis of the five color sets shows that there were only small color variations during the sunset, so most of the real variations are captured in the movie.

PIA05343: The Sun Sets on Mars

:eek:

http://photojournal.jpl.nasa.gov/animation/PIA05343