时间:2019-01-31 作者:英语课 分类:VOA常速英语2007年(十一月)


英语课
By Paul Sisco
Washington
14 November 2007
 


At the McDonald Observatory 1 in western Texas, a unique space program has been quietly underway for more than 30 years. It is called the Lunar Laser Ranging Program. VOA's Paul Sisco has more.


Research scientist Jerry Wiant has traveled a lonesome highway in western Texas to the McDonald Observatory in the Fort Davis Mountains almost every morning for 38 years.


Once there, Wiant powers up a high powered laser beam that travels to the moon and back several thousand times a day. "Light Amplification 2 by Stimulated 3 Emitted Radiation," he explains is how Laser gets its name.


It is all part of a study funded by the U.S. space agency, NASA.


The laser sends pulses of green light through a telescope, to four reflectors on the moon's surface. Wiant explains, "It hits the reflector that we are aiming at and then that reflector sends the light back."


Apollo 11 astronauts set up the first reflector when they made the first manned flight to the moon nearly 40 years ago. Subsequent Apollo mission's added two more reflectors, and an unmanned Russian mission sent a fourth.


"The fact that we can lunar range [target moon reflector with laser] at all is just short of a miracle," said Wiant


The lunar laser provides data on gravity, tides and spreading land masses here on Earth. It has also showed that the moon is moving away from Earth 3.8 centimeters annually 4.


NASA scientist Wendell Mendell says, "This information about the structure of the Earth and the structure of the moon is fundamental to our understanding of how planets work."


It is all in a day's work for Jerry Wiant, deep in the quiet hills of western Texas.




n.天文台,气象台,瞭望台,观测台
  • Guy's house was close to the observatory.盖伊的房子离天文台很近。
  • Officials from Greenwich Observatory have the clock checked twice a day.格林威治天文台的职员们每天对大钟检查两次。
n.扩大,发挥
  • The voice of despair may be weak and need amplification.绝望的呼声可能很微弱,需要扩大。
  • Some of them require further amplification.其中有些内容需进一步详细阐明。
a.刺激的
  • The exhibition has stimulated interest in her work. 展览增进了人们对她作品的兴趣。
  • The award has stimulated her into working still harder. 奖金促使她更加努力地工作。
adv.一年一次,每年
  • Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
  • They celebrate their wedding anniversary annually.他们每年庆祝一番结婚纪念日。
学英语单词
abstinent
alkal(a)emia
analyticities
aprotinin
Arbutal
arsenous compound
astrue
at a low cost
Babcock's clamp
bad urach
bafflingly
band-saw roll stretcher
biogeographers
boot cream
c-2s
Carolans
cellulose acetate rayon
chambered lode
chemical notation
chosisme
clausius (in calorie per degree)
computational cutoff rate
conjugal visitation right
Cross System Product
cut off state
Cyperus rotundus Linn.
dicentrarchus labrax
directly gripping
dracaena terminalis
dysorexia
effective communication
expense centre
fifth columnist
finishing drilling
formal logical system
FrontDoor
gaolbirds
hatlessness
Hohenholte
hoicked
huller rib
hypericine
invalidness
katunda
kingmamboes
Kooline
laser fuze
lifesharers
lithophyses
Lonicera hirsuta
manganous tartrate
maximum travel speed
mEq
minipumps
movie loop
muffle oneself up well
multiple electron
narrowmindedness
net transmission equivalent
nickel-titanium
non-affine deformation
non-circular shaft
noninducible
opossuming
ordinal interaction
par bond
paraboloid method
paramera
personal-liberty laws
Petroselinum crispum tuberosum
pheno-ether resin
polioencephalitis hemorrhagica
polycross seed
protein targeting
quadmire
quasi delicta
rimgale
rotor rocket
schroedinger equation
self-repellency
slignment wire
soemita
straight-set
streamgraphs
submarine pit
synchronous time-division multiplexers
synthetic lubricant fluid
Ségou, Rég.de
temple prostitute
the joys of winter
thirteenthly
tinkering around
to keep one's shirt on
tonoscillograph
train
trophoneurotic
typhus nodule
u-shapes
var. v. ophthalmomeningica
wills act
wooden framed mirror
working atmosphere