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
a cha
alleyn
art
arteria nutricias
as far as I can tell
astronomical twilight
auxiliary credit
available hydropower resources
bring an action against sb.
bring sth back
brynjolfsson
caincas
channel table
chilalgia
chloridium laeense
chokage
cleansable
combined springing
compressinal vibratin
conditioned climate
counter emf
craft and related trades workers
cricopharyngeal
criticisingly
Daoism
Democratic Republic of East Timor
densitometries
diff-locks
dimbulbs
earth elasticity
Ferrlecit
folktronica
fractional distortion
Francke's needle
freat
freezing duration
halely
Holmsveden
hotel building
Hymenogaster
inconels
injection refining
kirked
land use capability survey
large imperial
larr
Lebenswelt
literalizing
LlandoverianEpoch
lopresor
madra buba
meningoencephalomyelitis
mollycoddling
multicutter lathe
Neufchâtel-Hardelot
nicolar
nonpliant
octadic
orbit closure
overlap adjust knob
overstable
paddle wheel vessel
palaeohistological
Papes
pearly nautilus
pilule
pre-aeration
Primula woonyoungiana
Quotid
radial transformation
Rambus dynamic random access memory
ratio of peripheral velocity difference
reqd
res ipsa loquiturs
resistance thermometer adapter
Rhizopus nigricans
rib cage
right bundle branch block
roadside landingstrip
Rūkanpur
sedentarisation
semi-simple Lie algebra
serigrapher
sex ratio at birth
side run-off
skid steer
smoothing by sight
speckled glaze
sports fields
Stephanotis pilosa
student-level
suscitability
tabarly
tchambulis
temporal hour
thrombon
Thurmond, James Strom
trailing moment
tycoonship
unfit
Xisha
Zhang Zhidong