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
-spermal
adjustable for height
agency havas
amplifying relay
anti-overshoot device
asbestos-exposure
auliscus sculptus
battle group
be down for a count of
blanded
Blaxican
bonding equipment
bonneting
Borrentin
brain-derived neurotrophic factor
bull the buoy
call black white
cialdini
coiled macromolecule
common-battery set
community antenna television line extender
Corydalis harrysmithii
counterpropositions
cross head shoes
defined point on chip breaker
deviation
double ten
drimenene
dry chamber system
electric engine oil
entero-enterostomy
equate to
excreters
express train
familial goiter
femulen
floor thrust
free fatty acid
fuel-reprocessing waste
genus sciaenopss
group pension policy
gut it out
hydrogen-embrittlement
improve the shining hour
jyotirlinga
long forecastle
long shaft pendulum tool
makela
makeup water softening
mergener
methyl crotonate
nonoperating company
obv.
opposed shelf type vertical conveyer
osteochondromatous fibroma
overhead view
P-alkalinity
panabaj
pea-like structure
penguinery
permeability rise factor
polyfidelity
potassium chromic oxalate
pre-releases
preventive maintenance management
quiddity
quintafurcation
radell
radiotelegraphers
ramiz
release lever groove
resonance zone
right round here
ringroundabout
rowan atkinson
separated morphism
shaves
slaveowners
sloppinesses
sphericalness
sternothyreoideus
stokes component
suetty
supply and vent tank
swing transation
tallow oleine
technomyrmex horni
thermal comfort
things concealed
thrust sheet
tooth ga(u)ge
topological division ring
torsional vibration
ultramacroion
Union Astronomique Internationale
wannamaker
welsh cob
West Sussex County
wheel extension
yottasecond