[酷图] [新闻] 卡西尼号最新图片(2004年03月05日)

土星甲烷图片(2004年03月05日)

卡西尼窄角照相机2004年02月16日在距离6610万千米处使用特殊的滤光器拍摄了这张土星
图片。图片显示了高空大气中的云和薄雾。这张图片的比例是397千米/像素。

MT2光谱过滤器对电磁频谱的近红外区域进行采样。甲烷气体吸收这个区域中波长为727纳
米的辐射。图片中显示的是三个甲烷滤光器之一。它们将会用来估计云和薄雾的高度和厚
度。甲烷和氢气的混合气体是土星大气的主要成份。图片中较暗的区域表示强烈的甲烷吸
收，relatively free of high clouds；较亮的区域 are places with high, 较厚的云
which shield the 甲烷 below。相邻区域的不同亮度显示了云的不同高度和厚度。这张图
片显示了 a high thick 赤道附近的云 and a relatively deep or thin 薄雾环绕在两极
附近，以及不同的经度上不同的云层高度特征。图片同时还显示了南半球的高空大气扰动
。它一直持续出现在20世纪90年代哈勃太空望远镜拍摄的图片中。

图片中还可以看到土星的四个卫星。它们分别是(从右边开始逆时针方向)：土卫二(大小4
99千米)、土卫一(大小396千米)、土卫三(大小1060千米)和土卫五(大小1528千米)。土卫
一和土卫二的亮度被增强了三倍。

卡西尼—惠更斯任务是美国航空航天局和欧洲航天局的一个合作项目。位于帕萨迪那的喷
气推进实验室作为加州理工学院的一个机构，为位于华盛顿的美国航空航天局空间科学办
公室管理卡西尼任务。The imaging team is based at the Space Science Institute，
Boulder，科罗拉多州。

关于卡西尼任务的更多信息，请访问卡西尼主页：http://saturn.jpl.nasa.gov

Credit: NASA/JPL/Space Science Institute
Released: March 5, 2004 (PIA05381)
Image/Caption Information
原文如下：
PIA05381: Saturn Methane Image

The Cassini narrow angle camera took this image of Saturn on Feb. 16, 2004, from a distance of 66.1 million kilometers (41.1 million miles) in a special filter which reveals clouds and haze high in the atmosphere.
The image scale is 397 kilometers (247 miles) per pixel. The MT2 spectral filter samples a near-infrared region of the electromagnetic spectrum where methane gas absorbs light at a wavelength of 727 nanometers. In the image, methane gas is uniformly mixed with hydrogen, the main gas in Saturn's atmosphere. Dark locales are places of strong methane absorption, relatively free of high clouds; the bright areas are places with high, thick clouds which shield the methane below.

Image details reveal a high, thick equatorial cloud and a relatively deep or thin haze encircling the pole, as well as several distinct latitude bands with different cloud height attributes. It also shows a high atmospheric disturbance, just south of the equator, which has persisted throughout the 1990s in images returned by NASA's Hubble Space Telescope.

Four of Saturn's moons are visible (clockwise from above right): Enceladus (499 kilometers, or 310 miles across); Mimas (396 kilometers, or 245 miles across); Tethys (1,060 kilometers, or 659 miles across); and Rhea (1,528 kilometers, or 949 miles across). The imaging team enhanced the brightness of Mimas and Enceladus by a factor of three.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colo.

For more information, about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.

我和同学在晚上也观测了土星~~