时间:2018-12-30 作者:英语课 分类:国家地理2007年


英语课
Believe it or not, astrobiologist Penny Boston is searching for life on Mars by dropping deep into this heart of darkness. This is a lava 1 tube, a subterranean 2 cave formed by underground lava flows during volcanic 3 eruptions 4 that occurred thousands of years ago. And Boston has someone she wants us to meet.

Sometimes they are in crevices 5. Sometimes they are kinda hard to see.
Is this one, the scary monster reveals itself?
Ah! There is one.
Actually no. This is an extremophile.

We are looking for what we astrobiologyists call extremophiles in this environment. That means that they are organisms that are living in very difficult conditions. In this particular case, these organisms are living in a very cold cave right around freezing. They are making their living without benefit of sunlight and there is almost nothing to eat in this cave.

In recent years, scientists have discovered tenacious 6 microorganisms living in all forms of extreme environments. So if on Earth, why not on Mars?

We think that Mars is covered with lava tubes. We believe that by looking at organisms that live in these extreme circumstances on Earth, we can learn a lot about what to look for on Mars; and that, similar Martian organisms may be able to persist on Mars in places very similar to this lava tube.

To find out, Dr. Boston has created her own little Mars environment biospheres, essentially 7 exposing a range of microscopic 8 Earth life forms to various elements to be expected on Mars.

They have been subjected to Mars-like levels of high ultraviolet radiation, and Mars-like temperature cycles. We have given them atmosphere compositions from very low levels of carbon dioxide with nothing else to, perhaps, 1/10 the density 9 of Earth's atmosphere, and tested them under those conditions.

And so far, she's isolated 10 36 different strains of organism that thrive quite happily. So in theory at least, life could survive the harsh conditions of Mars except for one problem.

There is one thing for sure that we know, and that is that all forms of life on our planet require liquid water. We don't know if that's going to be true on other planets. But we think that where there is going to be life, there is going to have to be water.

astrobiologist: one who specializes in astrobiology, one who studies life on celestial

subterranean: existing, occurring, or done under the earth's surface

extremophile: microorganism that lives in extreme environmental conditions

tenacious: persisting in existence




n.熔岩,火山岩
  • The lava flowed down the sides of the volcano.熔岩沿火山坡面涌流而下。
  • His anger spilled out like lava.他的愤怒像火山爆发似的迸发出来。
adj.地下的,地表下的
  • London has 9 miles of such subterranean passages.伦敦像这样的地下通道有9英里长。
  • We wandered through subterranean passages.我们漫游地下通道。
adj.火山的;象火山的;由火山引起的
  • There have been several volcanic eruptions this year.今年火山爆发了好几次。
  • Volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。
n.喷发,爆发( eruption的名词复数 )
  • There have been several volcanic eruptions this year. 今年火山爆发了好几次。 来自《简明英汉词典》
  • Over 200 people have been killed by volcanic eruptions. 火山喷发已导致200多人丧生。 来自辞典例句
n.(尤指岩石的)裂缝,缺口( crevice的名词复数 )
  • It has bedded into the deepest crevices of the store. 它已钻进了店里最隐避的隙缝。 来自辞典例句
  • The wind whistled through the crevices in the rock. 风呼啸着吹过岩石的缝隙。 来自辞典例句
adj.顽强的,固执的,记忆力强的,粘的
  • We must learn from the tenacious fighting spirit of Lu Xun.我们要学习鲁迅先生韧性的战斗精神。
  • We should be tenacious of our rights.我们应坚决维护我们的权利。
adv.本质上,实质上,基本上
  • Really great men are essentially modest.真正的伟人大都很谦虚。
  • She is an essentially selfish person.她本质上是个自私自利的人。
adj.微小的,细微的,极小的,显微的
  • It's impossible to read his microscopic handwriting.不可能看清他那极小的书写字迹。
  • A plant's lungs are the microscopic pores in its leaves.植物的肺就是其叶片上微细的气孔。
n.密集,密度,浓度
  • The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
  • The region has a very high population density.该地区的人口密度很高。
adj.与世隔绝的
  • His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
  • Patients with the disease should be isolated. 这种病的患者应予以隔离。
学英语单词
Achillean
air pressure regulator valve
ask for a ruling
atonements
belay
big-businesses
bigram
botolph
brined meat
camera control operator
cathode half bridge
Centranthera tonkinensis
certificate of audit(or)
charing machine
Chorvoq
class-struggle
collision drill
coverboys
coveys
deliquity
drop-in commercial
drum-like
dry risers
Eastern Western
Egyptian grass
emulsio olei jecoris plscis
ensealing
evrythin
extraneous evidence
exudative lobular tuberculosis
family Ginkgoaceae
floating warranty
fried sliced pork
gamma activation analysis
gargulun
greenweed
gutenbergs
helium 3B phase
icaroscope
idiochord
incompatibility problem
infantile spinal muscular atrophy
inhibiting pulse
Jehovah-tsidkenu
kavans
knocks it off
ku niao su
landscape genetics
leichman
lime glass
longitudinal magnetic field probe
macro-function
master of the house
Mauritius
miniplant
Mitmachen
monitrice
mosswood
native XML database
non-uniform shock wave
on the down grade
out migrant
pelletierine sulfate
perseveraunt
post-coordinate
preselections
prochlorophytes
quavering
raising by dewatering with compressed air
ratless
respiratory enzymes
reverberation absorption coefficient
Rubrobacteraceae
ruling and balancing accounts
ruyschiana
sanitary pads
Sayatón
season duck
secondary industrial sectors
semiiterative
shareable routine
Siabu
siliceous wood
snoopily
software licensing
spastic unilateral paralysis
Stegnogramma
stomach types
superscribing
t-tube
tactic pattern
temporalls
tetraconate
thomas hopkins gallaudets
triacontahexaene
trichilemmal
Vallisneria denseserrulata
wastewater dilution
Wild-Barfield furnace
yard-wand
yeast contaminant