时间:2019-02-05 作者:英语课 分类:自然百科2012年


英语课

 And it’s here in a freezer that Messenger will encounter another puzzle: can ice exist on a planet so close to the sun?


 
It's only when the first radar 1 observations to the surface of Mercury were obtained back in the 90s that it was discovered that Mercury in fact, had what appeared to be polar caps in these first radar images.
 
Some corners of Mercury’s polar craters 3 are in permanent shadow. Here, on the most sun-baked planet of all, water seems to survive frozen in / eternal darkness.
 
The ice is contained in places where literally 4 the sun never shines, and so the ice is quested in these dark, interiors of craters of the high latitude 5 regions.
 
We found the same thing on our moon. In late 2009, the LCROSS mission crashed a probe into a deeply shadowed crater 2 confirming ice hidden near the lunar South Pole. Where did it come from? A comet? 
 
It's very interesting. Because we believe that the water in the earth, in its atmosphere, in the oceans, and even below the surface, probably came from the similar source, and so part of the mystery of Mercury is to try to find out where the water came from, and maybe that might help us find out where the water of earth came from. 
 
It may never be possible to send a human to Mercury, but how about a robot? In 2011, when Messenger arrives in orbit, imagine this tough little spacecraft circling a lonely planet a very long way from home.

n.雷达,无线电探测器
  • They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
  • Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。
n.火山口,弹坑
  • With a telescope you can see the huge crater of Ve-suvius.用望远镜你能看到巨大的维苏威火山口。
  • They came to the lip of a dead crater.他们来到了一个死火山口。
n.火山口( crater的名词复数 );弹坑等
  • 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》
adv.照字面意义,逐字地;确实
  • He translated the passage literally.他逐字逐句地翻译这段文字。
  • Sometimes she would not sit down till she was literally faint.有时候,她不走到真正要昏厥了,决不肯坐下来。
n.纬度,行动或言论的自由(范围),(pl.)地区
  • The latitude of the island is 20 degrees south.该岛的纬度是南纬20度。
  • The two cities are at approximately the same latitude.这两个城市差不多位于同一纬度上。
学英语单词
adrocaine
adzhars
air compressor bracket
Alan Lloyd Hodgkin
alizarin bordeaux ba
Allium aciphyllum
anistreplase
backed away
bankfull discharge
be highly necessary to
be proportional to
biliscopin
buzzeth
Bāqir, Jab.
calc-gneiss
cancel session request
charity stripe
chrysoretin
complete annealing
coraco-hyoid muscle
Cormatin
cousin-german
dayworks
deep-skier
delofts
displacement component
divinitize
economic refugee
effective cutting edge
Eleocharis ovata
epidemic hemorragic fever virus
equi-mass model
family Primulaceae
field jacket
filariform larve
file tag in
film plane
Fossa cubitalis
four-wheel garage jack
freewheeled
galvanizers
good organization
high-rater
hook someone up
hydrocarbon analyzer
in return for this
intermediate vadose water
interrupt queue head pointer
introduction agency
inversion of kinematic-chain
Janūb Dārfūr, Wilayah
Khawr, Sharm al
kurtzke
labda
machine vice
major plate
materials cost account
megapacks
melarsomine
mellitimide
modified factor system
morphine type drug dependence
multi-tapping
navigation and guidance
navigation light board
night-fishing
non-buyers
non-marketed
norm of progressive average
outlet edge of impeller blade
overspecified
pick a back export scheme
posterior spinocerebellar tract
precentral gyruss
prison ring
rate of cure
reenthroning
reglutinate
relative wear of the tool flank
ringbird
running free
sceptry
SDFG
seed aspirator
septate parenchyma
sequesterment
shillman
super atmospheric pressure
superalumag
suspended silo unloader
tanenhaus
thiamine tetrahydrofurfuryl
three cotton genotypes
transformer with ring core
transverse intersection
tutorest
vigna radiatas
weathered stone
WKBJ method
womanises
Xicohténcatl
zizzo