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
airdry
Al Kawah
an old head on young shoulders
anapest
anthraconite
antonie
apartment service area
Aschoff body
back-projections
Ban Tanong
bedroomy
bipolar frequency divider
borne system
boxcar function
candle-lighter
carolanne
cathode layer method
class play
cleofil
coal sizes
common laws
compulsory exercise
control feature
counter-defender
creature comfortss
cyberrelationship
cystica fibrous osteitis
Dowden, Edward
dutycycle
effective picture signal
enantioseparate
estrone
extravisual zone
family cetorhinidaes
fatou lemma
fissureina
frame front extension slab
full penetration single pass weld
fuyu
ghost station
glabripetalus
gram-atomic
hemimerid
honey-wheat
Hotta Masayoshi
hypoimmunogenic
indivisus
induced bacterial antagonism
infix syntax
infringing on
interleukin-6(IL-6)
Lonkin
meroistic ovariole
metalfluorescent indicator
metazonic acid
miohippus
multichannel sea surface temperature retrieval method
multiplier quotient register
natural target
non-planar
nucleus gracilis
Oberdorf bei Immenstadt
oil pressure test or tightness
ornithomyia fuscipennis
oxaloacetic acid
periodic media
photo chemistry
piling-ups
quenching and age-hardening
recumbently
regenerative hyperplasia
retail strategy
Rh negative
right-handed multiplication
rogen
roughsetting
safe strategy
saprolith
Seattle Seahawks
sill of side-scuttle
single cloth
sludge dewatering
spasm bands
stream steam sterilization
Sturm's conoid
Swertia angustifolia
synionism
ticket-holder
tickles the ivories
Tomahawk L.
total absorption peak
tousles
towel clamp towel forceps
transfer-case to front axle
tyre life
unemployment compensation tax
unit assembly and installation of auxiliary
univalent shift(person 1956)
unspang
very high frequency omini-directional radio site
wood card
zero stress-optical constant