英语听力：自然百科 行星旅行指南：火星 Mars—17

 It is chemically impossible for methane¹ to survive for long in the Martian atmosphere, so it must have been released recently. 

 

Now what makes methane? Cows make methane? Probably not cows. Oh, microbes, various sorts can release methane, there are a variety of geographical² processes, volcanoes can release methane, so the mere³ fact that there is methane doesn’t say life, but either way, the methane says that Mars is an active planet. It is either biologically active or it is geologically active or both. 

 

The methane release appears to be seasonal⁴ and links to areas of suspected subsurface ice, ice found exposed in fresh craters⁵, has proven that water lurks⁶ not only near the poles but also much closer to the equator, it is pretty clear, that if the Viking Lander had dug just 4 inches deeper, they would have reached this ice and perhaps a totally different conclusion about life on the red planet. 

 

So if Mars has any life at all, whether it is so small you can only see with a microscope, or they had a mammoth⁷, it wouldn’t matter to me, it’s the whole question of : is there life at all on Mars. 

 

Either way, there certainly will be life on Mars, the moment the first human traveler arrives. 

 

The fact that there are no scheduled flights to Mars hasn’t stopped people from preparing for the trip, and for a flight like this, planning is everything. And there we go. 

 

In 2009, 6 men walked into a series of connected rooms inside a warehouse⁸ in the Moscow suburbs and shut the door behind them for 3 months, they took all their food with them and drank recycled water, the only communication with the outside world was electronic, with a 20-minute/ delay. They were trying to simulate a flight to Mars.

1 methane   

n.甲烷，沼气

参考例句：

• 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。

2 geographical   

adj.地理的；地区(性)的

参考例句：

• The current survey will have a wider geographical spread.当前的调查将在更广泛的地域范围內进行。
• These birds have a wide geographical distribution.这些鸟的地理分布很广。

3 mere   

adj.纯粹的；仅仅，只不过

参考例句：

• That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
• It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。

4 seasonal   

adj.季节的，季节性的

参考例句：

• 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。

5 craters   

n.火山口( crater的名词复数 )；弹坑等

参考例句：

• Small meteorites have left impact craters all over the planet's surface. 这个行星的表面布满了小块陨石留下的撞击坑。 来自《简明英汉词典》
• The battlefield was full of craters made by exploding shells. 战场上布满弹坑。 来自《现代英汉综合大词典》

6 lurks   

n.潜在，潜伏；（lurk的复数形式）vi.潜伏，埋伏（lurk的第三人称单数形式）

参考例句：

• Behind his cool exterior lurks a reckless and frustrated person. 在冷酷的外表背后，他是一个鲁莽又不得志的人。 来自《简明英汉词典》
• Good fortune lies within Bad, Bad fortune lurks within good. 福兮祸所倚，祸兮福所伏。 来自互联网

7 mammoth   

n.长毛象；adj.长毛象似的，巨大的

参考例句：

• You can only undertake mammoth changes if the finances are there.资金到位的情况下方可进行重大变革。
• Building the new railroad will be a mammoth job.修建那条新铁路将是一项巨大工程。

8 warehouse   

n.仓库；vt.存入仓库

参考例句：

• We freighted the goods to the warehouse by truck.我们用卡车把货物运到仓库。
• The manager wants to clear off the old stocks in the warehouse.经理想把仓库里积压的存货处理掉。