时间:2019-01-23 作者:英语课 分类:探索与发现2014年


英语课

 Tim has developed a map to visualize 1 their location. And on that map, the most important are the Near-Earth asteroids 3, the ones closest to the planet. On the screen here is a map of the solar system. 


 
And I’ve got the Sun in the centre and the third planet out here would be that of the Earth. The red dots in here are actually Near-Earth asteroids. The green ones are the regular Main-Belt asteroids. 
 
There are over 9,000 Near-Earth asteroids. But there’s one type that’re particularly concerned to locate, those asteroids that are over one kilometer in diameter. An Earth impact with one of these would spell disaster. Tim’s data reveals that there are 900 asteroids bigger than a kilometer in those dangerous Near-Earth orbits. But he has some good news.
 
Right now, there’s no information that any of those large objects will hit the Earth in the next 100 years. So we’re safe from impact of those objects for at least 100 years. So there are no catastrophic asteroid 2 impacts on the horizon. But there are still dangers out there. 

vt.使看得见,使具体化,想象,设想
  • I remember meeting the man before but I can't visualize him.我记得以前见过那个人,但他的样子我想不起来了。
  • She couldn't visualize flying through space.她无法想像在太空中飞行的景象。
n.小行星;海盘车(动物)
  • Astronomers have yet to witness an asteroid impact with another planet.天文学家还没有目击过小行星撞击其它行星。
  • It's very unlikely that an asteroid will crash into Earth but the danger exists.小行星撞地球的可能性很小,但这样的危险还是存在的。
n.小行星( asteroid的名词复数 );海盘车,海星
  • Asteroids,also known as "minor planets",are numerous in the outer space. 小行星,亦称为“小型行星”,在外太空中不计其数。
  • Most stars probably have their quota of planets, meteorids, comets, and asteroids. 多数恒星也许还拥有若干行星、流星、彗星和小行星。
学英语单词
acoustic homing system
address matcher circuit
alphanumeric program
Anicetus
antirheumatoid drug
apparent turbulent stress tensor
aseptic filling
astronomic transit
atlee
automated batch mixing
Bac Giang, Tinh
bioconcentration
bistable polarization
branch coverage testing
brems
bus hut
cant rail
checking book
chrysanthemum leucanthemums
close-to-nature forestry
cobalt slass
coffee black beans
coodes
crested penguins
crystal-controlled
customer evaluation
daryosphere
diffused base transistor
distributed element
ditylenchus
externally-imposed
flower primordia
foresworn
full crystal
gateway charge
geographical classification of 8oils
guardlike
heteromorphic chromosomes
heterosperminous hybridization
histoimmunological
historical jurisprudence
horn cleat
hydroaluminations
iraqgates
knife tool
laughland
lent an ear to
liasons
limit of aperidicity
local buffer storage
lomasome
longitudinal dispersion
low transmission
mazatzal pk.
medical nomenclature
microcode assembler
mild-mannered
mine swept route
Mugila, Mts.
multispectral satellite data
noboes
obv
Osborne, L.
Paranari
patently
payment notice
Perisporiales
pick his steps
price plan
primary vaccination
protocollyris sauteri
pterygomandibular
Puusepp's reflex
raddicle
read-message
real-time data structure
recosting
reverse mottle
RNA probe
rosin adduct
scutellarin
segmented address space
spread for
sudor anglicus
Symes
symmetric game
tank clean-out opening
televisuality
the eight manifestations of infantile convulsion
theophanous
tisiyeh (tasiyeh)
torpedo bombardment aeroplane
tribenzylethyltin
trickle-irrigated
triphenoxazin
two for one twister
unquenches
versche
vica
wear resistant alloy steel
widely spaced stanchions
zapanta