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
Abelvaer
absolute moisture content
all-metal mirror
Amphizona
apposition growth
Astaffort
battery reverse switch
beatenest
body centred cubic
branch structure
byplot
carcharhinuss
cargo ship construction certificate
checkhead
chisox
clean it
cofinal partial directed family of points
command-driven program
continuous-wave interference
control gage
copper-plate
Cugy
dactylotype intergrowths
derivating agent
dicotyledony
dijudicated
diploid cell
Drechslera
dual thrust rocket motor
dual-use line
dytiscidaes
earth conductivity
emergency overspeed trip
flexible wiring
Fluchthorn
foredunes
funicular line
gage cock body
genus Pterodactylus
genus xylopias
gossipings
heezed
height of summit
hemoclastic tissue
heterotactic
histomonosis
Hypotremata
internal area ratio
Itarsi
Kash.
kastanozems
Khānigaon
life-sized
locally finite
marine glues
meet with good results
mirch
multiple stage ampification
nanocomplex
navicula tuscula
nearest neighbor interaction
non intellectual
nondiversifiable
nontrees
Opatov
oral-aural
OreticHydrochlorothiazide
organometallic condensation polymer
over your head
partitioning of matrix
pipe-shaped
Pityrosporum malassezii
place word
pointsettias
postsphenoid
power knitting machine
Qafl
r-ny
radio-frequency carrier
refer to...as
remix
rhythm method of birth control
screw sth out of sb
shelved
signal code capacity
slosh mass
snipes
solar array power at the BOL
summer fallow field
Supergames
tailstock center sleeve
tavies
thermal insulation tape
time-axis shift
transient intermediate
transplant survival percent
tropical cyclone
Vistula Lagoon
white ash
wisdom literatures
work to
YAAP