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
-rel
actual rate of wastage
administrative program
advanced level examination
AF input impedance
Aghchourguit
apocryphal work
apodizations
arolella
ask for instructions
at anchor
Bangkal
basu
bevel pinion shaft carrier
bogsted
Boy and Girl
bunny slopes
coefficient of compressibility
combined balance sheet all fund
contact miss
corresponding leg
curve break
D-Sorbtol
decentraliser
deformity of ear
Dictyoptera
digit circuit
diphenamid
disc sanders
disigned waterplane
doanes
Dolocap
drawing chain
duodenopylorectomy
elice
end tag
English legal system
ESA-4
euergasia
evaristuss
feiseanna
fluid power transmission
FOR statement syntax
fun sponge
glauc-
hacksters
have an account to settle with sb.
hyperlastic
incandescent detonator
indicating defining occurrence
internior angle
Lake Charles
life-saving equipment
marofsky
marrish
massacrous
maximal detectable range
meaniing
Merries
methylacetylcholine
NATR
neurodendron
ornerily
osb
plastiosome
policy studies
preapoptotic
Principle of Liability Without Fault
Pterygogenea
quinin oleate
razzmatazzs
RBC-A
regular unbiassed critical region
restricted fare
revertive pulses
rosarist
SDDS
segregationalism
semirigid plastic
shrewdness
shrp
sight feed gage
soft-wood
spray injector
St-Amand-sur-Fion
storability
stripes'
synchronous altitude spin stabilized experiment
tannic acid ointment
tetrahydroxybutane
thermionic engine
Tichocarpeae
torus manus
towing rail
undespoiled
unhamper
untenured
upreaching
vacuum power brake
vinyl n-butyl ether
voice group call service
Wangka