机遇号将探索火星的新地貌

标签:
杂谈 |
分类: 科学与技术 |
2013.08.21
机遇号拍摄的照片显示了两种不同的地形的衔接,前景为颜色较浅的岩石,远景为颜色较暗的岩石。
华盛顿——好奇号(Curiosity)火星漫游车自2012年8月登陆火星后蜚声全球。与此同时,在火星表面进行探测的美国航空航天局(NASA)的老资格漫游车机遇号(Opportunity)正悄悄等待它在这个红色星球上的第五个冬季。
机遇号正在探测被美国航空航天局喷气推进实验室(Jet Propulsion Laboratory)的科研团队命名为“索兰德高地”(Solander Point)的火星区域,两种截然不同的岩层在这里交汇。机遇号将在那里度过一个冬季,确定这片区域可以透露哪些有关火星地质史的资料。
机遇号自2004年1月登陆火星以来已经在火星上安然度过了5个冬季。由于火星绕太阳公转的速度比地球慢,与地球相比不太经常出现冬季。机遇号目前正朝着北边坡地的某个地点前进,漫游车的太阳能电池板将在那里朝着冬季的太阳倾斜,从太阳获得重要的电力补充。
加利福尼亚(California)的喷气推进实验室的机遇号项目科学家马特·戈隆贝克(Matt Golombek)说:“我们知道机遇号行驶一天就可抵达那块朝北的坡地,但现在我们尚不需要去那里。我们有时间探测索兰德高地底层周围两个地质单元的接合部。地质学家热衷于研究这些接合部。”
机遇号目前正在探测的地质接合部是一处被称为“伯恩斯组”(Burns Formation)的地点。这里有含硫酸盐的矿物质存在。这为远古火星环境含有硫酸一事提供了证据。这个结构隆起地带因撞击而在附近形成了一个大坑,毗连更古老的岩石。火星轨道飞行器所得到的观测和机遇号在火星表面其他地方的探测向研究人员表明,更古老的岩石中可能含有在潮湿和较低酸性的环境下形成的矿物质。
科研团队计划在12月中旬之前让机遇号抵达朝北坡地,虽然他们预期让机遇号在整个冬季都保持移动。漫游车每日接受的光照强度将在2014年2月达到冬季最低点。索兰德高地为漫游车提供了可供其在整个冬季继续进行研究的岩石露头。
机遇号及其伙伴勇气号(Spirit)在2004年4月完成了为期3个月的主要使命。这些行星探测器登在登陆后仅几个月内就发现了火星上曾经存在潮湿环境的证据。
此后,机遇号和勇气号执行了几年的扩大使命。勇气号在2010年登陆火星的第4个冬季停止运行。机遇号也显示出一些节点活动失灵等老化迹象,但在继续完成探索和科研任务。
Read more: http://iipdigital.usembassy.gov/st/chinese/article/2013/08/20130821281446.html#ixzz2clicCHG4
Opportunity Explores New Martian Landscape
20 August 2013
This Opportunity snapshot shows the abutment of two different formations, lighter rock in the foreground and darker in the distance.
Washington — The Mars rover Curiosity has become an international celebrity since landing on the planet in August 2012. In the meantime, the senior NASA rover on the Martian surface, Opportunity, is quietly preparing to tuck in for its fifth winter on the Red Planet.
Opportunity is studying an area that the scientific team at NASA’s Jet Propulsion Laboratory (JPL) has dubbed Solander Point. Two very different rock layers join up at this point, and Opportunity will spend a winter there trying to determine what the site reveals about Mars’ geologic history.
Since it landed on Mars in January 2004, Opportunity has survived five Martian winters, which occur less frequently than on Earth because of the planet’s slower orbit around the sun. Opportunity is now heading for a spot on a northern slope where the rover's solar panels will be tilted toward the winter sun, providing an important boost in available power.
“We know we could be on that north-facing slope with a one-day drive, but we don't need to go there yet,” said Opportunity project scientist Matt Golombek at JPL in California. “We have time to investigate the contact between the two geological units around the base of Solander Point. Geologists love contacts."
The geological contact that Opportunity is now investigating is a site known as Burns Formation, which includes sulfate-bearing minerals providing evidence of an ancient environment containing sulfuric acid. This formation borders older rocks, uplifted by the impact that formed a nearby crater. Observations by Mars orbiters and Opportunity's work elsewhere on the surface suggest to researchers that the older rocks may contain minerals that formed under wet and less acidic conditions.
The team plans to get Opportunity onto the north-facing slope before mid-December, though the team expects to keep the rover mobile through the winter. Daily sunshine for the rover will reach a winter minimum in February 2014. Solander Point offers rock outcrops for the rover to continue studying through the winter months.
Opportunity and its twin rover Spirit both completed their three-month prime missions in April 2004. These planetary explorers found evidence within only a few months of landing that a wet environment had existed on Mars in the past.
After that, Opportunity and Spirit conducted years’ worth of extended missions. Spirit ceased operations during its fourth Martian winter, in 2010. Opportunity shows symptoms of aging, such as loss of motion in some joints, but continues to accomplish exploration and science.
Read more: http://iipdigital.usembassy.gov/st/english/article/2013/08/20130820281409.html#ixzz2clidoGpw