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
Abelian integral
american magpies
amidostomums
amplification
anticrash
apogonichthyoides nigripinnis
atteint
beef tongue
Benjamite
billion electron volts
broad-bean plant
centre to centre distance
Chlorococcum
cisternas
cobalt deficiency anemia
coefficient of riding quality
combined derivative spectrophotometry
cotinuous sampling
cutterbar
decompiling
desulfitobacteria
dialystely
discrete fourier series (dfs)
disregarded income
divine husbandman
double-disc lapping machine
electromagnetic gear
electrophoresis meter
Emmel process
Federal Register Act
focussable
foot mark
free physical block
go on the air
good articulation
Gromnik
ground shrub
humus stratum
hydraulic efficiency operated bulkhead valve
infestious
integrated support requirement
internal consistency reliability
InternetCash
jaw jaw
juniper berry oil
kuvis
law-worthy
lithology
live animal's rate
lost days
mammillotegmental tract
marketing-oriented
Masera di Padova
money-conscious
mucous tunic
N- vinyl-2-pyrrolidone
N-acetylthiophenine
NCVO
necrotics
nozzle jet dryer
oncological pathology
operational sequential diagram
order interval
ovvertriage
personnel signaling system
petit fours
pilot valve (pneumatic)
PMFIS
polluted seawater corrosion
popular electron microscope
powder molding
pre-link
prominent peak
Qabri Baxar
Qafqafā
quaternary parasite
Runnel.
Sangalkam
shishkin
shovelful
soft focus lens
solingens
somatosplanchnopleuric
space charge separation
spacebars
spare parts allowances
speed adjusting device
spitously
spk.
sulfonationreaction
tagwen
tax collection system
Toriphiles
tracheal annular ligaments
two-step design
ultralow
unverifiability
urinous infiltration
vacancy by election
valve voltage regulator
wire drawing compound
yap i.