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
adviewing
andrena cheni
anillo
antacoid
bosss
both-to-blame collision clause
cephalothoraxes
chalybeate
coalmie
color-apparent magnitude diagram
command file application
concentrator unit control
coppelling
corn crusher
dechoker
diploid sporophyte
dolmens
down-weight
Ewood
expenses form
fair-handed
fallen earthquake
five roll idler
five-by-five
flying horse
fratty
gastroduodenoscopy
gel electrophoresis
graduated L-square
GS pump
heat-drawn wire
high candle power
High-Churchism
icing-glass
in the nick of time
Inachis
infrared spectrometer
intake pipe
intermarine
isolated reservoirs pressure
Jewdom
Khwarizmi, Al-
labelled network
lecturee
Low Middling Lighter Spotted
ltpi
Lyatoga
manageresses
Mecigoxin
message-level
monodehydroascorbate
Monte Bello Is.
monus
napeas
natural-draught cooling tower
non-congealable
Oskara, Mys
oxygen carrying capacity
paseido-intraligamentary
photon trapping
plate appearances
poliodystrophia
pre-press operations
preleukelic
preparation for starting
price-baseds
procedure division statement
propagandistic
reasons and excuses
recontribute
refrigerated cargo carrier
regulating current device
reticulum cell sarcoma of bone
revertents
rigid insulation
rufigallic acid
rundown circuit
scattering problem
Segway HT
sexphobe
signless integral
single isolated bubbles
Slavo-
small sample time-series study
south equatorial drift current
steel cylinder rectifier
stillingic acid
supporting arms
the lily
thunder storm day
took with a grain of salt
Touch-a-Matic
trait and factor theory
transpalatal
triflusal
turned over to
unamortized debt expense
unticked
uploaded
yttrium ferrite
Zenza
zero sequence protection