SSS 2009-01-16
时间：2019-01-08 作者：英语课 分类：Scientific American(一)月
This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute.
There’s definitely methane 1 on Mars—and there are seasonal 2 variations of how much is being released into the thin Martian atmosphere. Which means that Mars is still active geologically. Or that deep underground, something is or was alive. Or both. NASA and university scientists report the finding in the January 16th issue of the journal Science.
Researchers studying the Martian atmosphere discovered and measured methane levels over the last few years, using telescopes with infrared 3 spectrometers. These instruments identify chemical compounds by analyzing 4 their unique light absorption properties.
They found that Mars methane is being released as concentrated plumes 5 at specific latitudes 6. Such plumes could come from various kinds of geological events. Underground bacterial 7 communities could also be producing the methane. Or now-extinct living systems could have produced the methane long ago, with it only now being released through pores or fissures 8 created by seasonal temperature variations.
On earth, 90 percent of the methane in the atmosphere comes from the biochemical activity of life. The rest is produced by geochemical processes. The Mars methane’s specific isotopic 9 makeup 10 could reveal whether its origins are biochemical or geological.
Thanks for the minute for Scientific American's 60-Second Science. I'm Cynthia Graber.
- The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
- Methane may have extraterrestrial significance.甲烷具有星际意义。
- The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
- The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。
- Infrared is widely used in industry and medical science.红外线广泛应用于工业和医学科学。
- Infrared radiation has wavelengths longer than those of visible light.红外辐射的波长比可见光的波长长。
- Analyzing the date of some socialist countries presents even greater problem s. 分析某些社会主义国家的统计数据，暴露出的问题甚至更大。 来自辞典例句
- He undoubtedly was not far off the mark in analyzing its predictions. 当然，他对其预测所作的分析倒也八九不离十。 来自辞典例句
- The dancer wore a headdress of pink ostrich plumes. 那位舞蹈演员戴着粉色鸵鸟毛制作的头饰。
- The plumes on her bonnet barely moved as she nodded. 她点点头，那帽子的羽毛在一个劲儿颤动。
- Latitudes are the lines that go from east to west. 纬线是从东到西的线。
- It was the brief Indian Summer of the high latitudes. 这是高纬度地方的那种短暂的晚秋。
- Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
- Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。
- Rising molten rock flows out on the ocean floor and caps the fissures, trapping the water. 上升熔岩流到海底并堵住了裂隙，结果把海水封在里面。 来自辞典例句
- The French have held two colloquia and an international symposium on rock fissures. 法国已经开了两次岩石裂缝方面的报告会和一个国际会议。 来自辞典例句
- The isotopic signatures of most ancient limestones indicated the same process. 大多数古代石灰岩的同位素特征说明了同样的过程。 来自辞典例句
- Isotopic discrimination is not likely. 同位素甄别是不可能的。 来自辞典例句