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
adult body
Aighton
aminourea hydrochloride
Aphroditus
autohormonoclasis
beam intercept
beccafico
bending equation
biocharacteristics
bismuth triphenyl
black tarantula
bridge to bridge radio telephone
c.c.p.r.
central detector
chagomas
chthamalus moro
clean core
Coelodiscus
cold-front thunderstorm
compounding room
comprehensivize
conspergens
Corispermum confertum
deep impurity state
deleveraged
destructive
diamino monocarboxylic acid
dominick
dry cargo ship
dry point
drying indicator test
dyscalculics
El Naranjo
engineering approach
estro
euphorbiums
ex (exchange)
false coxa vara
germ roll
giga
gliding model
gronked
high order precedence grammar
hurry down
IBM Power Systems
idling running
instrument and control
intrauterine insemination
inviabilities
knotter
Kohlrausch
L-CMRG
lacquer tree, lacquer plant
macrochaetus serica
manner of articulation
market ability
misconduct
multiple spindle broaching machine
non-ledger assets
northwestwardly
NSGCTT
Opening tag
oscillatory extinction
outmuscle
overdevelops
paddle-wheeler
Pegaline
pelvifemoral
pepinnier
Petrer
pharmacias
phoca groenlandica
photorefractory
podocarpus nivaliss
polypropylene random copolymer
potencial
preponderations
previous chapter
pyin
Quiscamote, Cerro
rancke
renounce claim to an inheritance
road sodas
savants
schnozzles
scree iron ore
seat cushion angle
solid epitaxy
squamous cell carcinoma of palate
statistic analysis
subgenital porticus
swap order
tender collar
time division multiplexer
to all appearance
trichlormethane
tripod bolt
Ubaitaba
underwater demolition
where one lives