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
4-Nitrometaxylene
amortization of patents
anelectrics
bacillus pneumonicus alilis
backing ring
bisdigitoxoside
Brush under the carpet
Bunge's spoon
cargo loaded
chain rule
charlery
clan armed fighting
cliffordville
cochleosaccular degeneration
colodny
connection box
counterweight fill
cross feed carbon
daiko
darksomeness
deep-freeze locker
departure of tidal hour
disjoint elements
drag link ball socket
e-nfs
ebulliometry
electronic data processing technology
engine overspeed switch
enshroudest
enzinopsis zepa
eramin
Eriocaulon sclerophyllum
flavaspidinol
forgery of negotiable instruments
frequency shift keying
GANU
genelogi
Gorokhovo
have a wash and brush up
have the law on
heygate
high rubber mixing
high-values
Hirsutodontus
hydrodynamics of fishing gears
hydroelectric project
internationalization of capital
inverted-cone antenna
isophenergan
leishmanial
lemon spirit
Little Miami River
matt coating
maximum lateral amplitude of bridge
mesoanalysis
MOLSO
muck-fork
niobium oxide
nonintuitively
nuclear repulsion
one-to-one printing
orometry
Osmedysphoria
otherdom
overstamp
p-adic formal group
Palmarella, Col de
parallel-axial extinction
peripheral foreland basin
Peromyscus maniculatus
pices
Plains Cree
ponceau R
postmortem autolysis
prescind
ram recovery
ramleh
red wax mesh for retention
reggae-ish
rusty tinamous
satsuma rubrolaeva
seismoastronomy
Sensationdermal
set going
sharpest
shell receiver
shuttle conveyer belt
stumpers
Stöllet
symbolic goods
take time out to
taon
tongueflowers
trims down
Turing computability
unslippered
vane motor rotary actuator
weather driven
wii
withincommunity diversity
work safety