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
1/D
accidental loss(AL)
acetic hydroperoxide
acrrospiroma
aerodynamic guidance
amedi
arrendation
arteria genus descendens
ASBO
bieldy
block-printing
body-shops
border mutual trade management
branles
bulkages
cape colonies
Castro Laboreiro
ccca
cdfis
centanni
cererian
climatic anomaly
communication system protection
constant humidity cabinet
construction division
continuous discounting
copper coating
coriaceo-reticulate
Daq-jiu
de-fragments
deadman method
diamino acid
dissolvible
distance protection
distributed-computing
do sb out of sth
dusken
ectotrophic, ectotropic
electroacoustical reciprocity theorem
endorse over
exceptional remedy
flooring plate
Giglio Island
glacial stairway
goverment bonds outstanding
haggag
heinrich engelhard steinways
helminthosporium spot
high level language architecture
high-technology industry
identifier without type suffix
immunologic(al)
jary
lasik surgery
letting agency
logical product
material man
method of forming
moderate-duty service
Natsin
odd half-spinor
penmate
perichondral ossification (or perichondral bone formation)
plate glass edge grinding machine
polygenetic regeneration
praiseworthier
pre-detection integral
prism block
procedure return
protolophules
pucks
pulse feeder
quadratic estimator
redneck cocaine
repetitive addressing
rotary vane thrower
Rubus wardii
Rusovce
sanitation department
scouring of river banks
sensitized medium
seriflux
sleeper pitch
smolar
square law response
submerged-arc furnace
sulfoaluminate
surditas
synthetic nitrogenous fertilizer
t back
tea panning
tenellum
trigger action relay
trimethadione
tsaritsyns
universalizable
vaccinate
variable capacity pump
vorobyov
what if
winding displacement
winding frame