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
admit og no doubt
APP (Atomic Power Plant)
army serial number
at other times
BCVLV
beam communication
bills for collection
bluish-green argon laser
Brotterode
Caledon
cape towns
characteristic of dampness being heavy and turbid
chiliburgers
civil traffic computer-routing system
click one's tongue
competitive decay
coruscate
Croppa Creek
curatrices
diffuse endometrial carcinoma
Eastern gate
enter the lists
ethiopias
exogenous sampling maximum likelihood estimator
firm-level
force
genus Chilomastix
giving over
gyroelongated
hallooing
hanafin
heavy-chain
high voltage support frame
home card
hot lab
hunger march
instantaneous velocities
interlingually
Jacobines
john osbornes
k'meyer
Kalwaria Zebrzydowska
klebsiellosis
knock characteristic
lamp fitting
laser-tracking
letterbound
lever box
lipophilic exchanger
lunate surface
machinedependent
mean point of impact error
medium road oil
moving-company
multipion
mutagenizes
n. p.
natural subsidized solarpowered ecosystem
nerve sedative
non-fat dry milk
non-metal gitology
non-repetitive peak reverse voltage
nycti-
off-axis response
overpursued
paganish
pan boiling
para-ortho conversion
path of typhoon
pentahedroid
picture gate
plow horse
potassium perchromate
powerbridge
presence sensing device
principal party
rabbitlike
retraction stroke
Rhodiola wallichiana
runfola
salting-out elution chromatography
say thank you
scheme competition
sign one's own death warrant
silicone releasing agent
sissotorin
soda oil
solution heater
spare tag
sprelves
stage screw
submergible roller dam
summer form
super charge
thanatophobic
the web of life
thermoascus crustaceus
Tower City
ut dictum
valve facing
vinyl asbestos tile
zero geodesic