首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A new look at an asteroid orbiting the sun shows it could possibly smash into the Earth with tremendous force. But experts say
A new look at an asteroid orbiting the sun shows it could possibly smash into the Earth with tremendous force. But experts say
admin
2012-10-23
77
问题
A new look at an asteroid orbiting the sun shows it could possibly smash into the Earth with tremendous force. But experts say the potential impact is still 872 years away, time enough for the speeding space rock to alter its course.
Named 1950DA, the asteroid--1 kilometer wide--is the most threatening to the Earth of all of the known large asteroids, but the odds are only adout one in 300 that it would impact the planet, researchers said. "One in 300 is pretty long odds," said Jon D. Giorgini, a scientist in Califonia. "I’m not personally going to worry about it. It is so far in the future that lots of things could change."
There are approximately 1,000 asteroids bigger than a kilometer that can pass near the Earth in their orbit of the sun. About 580 have been found and their orbits plotted. Of these, only 1950DA represents a possible threat. Scientists continue an effort to identify all the other large asteroids that pass near the Earth, and it is their great hope that they don’t find any that are greater threats. If 1950DA did hit the Earth, said Giorgini, it would have planet-wide effects, setting off fires, changing the weather and perhaps creating immense tidal waves. But it would not be a planet killer like the asteroid thought to have snuffed out the dinosaure some 65 millions years ago.
Asteroid 1950DA was first discovered in 1950, but then not noted in astronomy logs again for decades. It was rediscovered in the year 2000 and in March 2001 whizzed within about 77 million miles of Earth, giving astronomers an opportunity to gather visual and radar readings. From that, the astronomers projected the orbital path 1950DA would take on its next 15 near passes of the Earth--over a period covering nearly nine centuries. For the 15th near pass, on March 16,2880, the analysis showed it was mathematically possible, though unlikely, that the asteroid could hit the Earth.
He said the highest probability is that the asteroid in 2880 will miss the Earth by about 290, 000 kilometers--a distance closer than the 370, 000-kilometer orbit of the Moon around the Earth.
According to the passage, which of the folloving statements is true?
选项
A、Scientists have managed to know more things about asteroid 1950DA
B、Many people seem to be worried about the predicted asteroid smash.
C、Scientists are atill quite optimistic about man’s future.
D、The Earth is faced with frequent threats from space.
答案
A
解析
第4段说2001年1950DA划过地球“giving astronomers an opportunity to gather visual and radar readings. From that, the astronomers projected...”可以得出,人们对1950DA已经有很多了解。
转载请注明原文地址:https://kaotiyun.com/show/qG9O777K
0
考博英语
相关试题推荐
Uponreachinganappropriateage(usuallybetween18and21years),childrenareencouraged,butnotforced,to"leavethenest"
Uponreachinganappropriateage(usuallybetween18and21years),childrenareencouraged,butnotforced,to"leavethenest"
Thinkofallthecriminalswhohavekilled,allthesoldierswhohavekilled;considerthemassmurderofJewsinNaziGermany.
Language,likefood,isabasichumanneedwithoutwhichachildatacriticalperiodoflifemightbe______anddamaged.
Thatintelligence(tests)actually(give)ameasurementoftheintelligenceofindividuals(are)questionedbysome(eminent)ps
ItwasnotuntilmodernscholarshipuncoveredthesecretofreadingMiddleEnglishthatwecouldunderstandthatChaucer,farfr
InEngland,LatinappearsnevertohavesupersededtheoldGaelicspeechamongthepeople.
Theboycouldnotreconcilehimselftothefailure.Hedidnotbelievethatwashislot.
Aftersomanynightsof______,Mrs.Constabledecidedthatshereallymustseeadoctor.Shecouldnotcontinuetolieawake,n
Inthelongrunagovernmentwillalwaysencroachuponfreedomtotheextenttowhichithasthepowertodoso.Thisisalmost
随机试题
依照我国《土地承包法》,承包方对取得的土地承包经营权享有流转的权利,该权利包括()。
求在x轴上截距为2,且过点(0,-1,0)和点(2,1,3)的平面方程.
防治哮喘最有效的方法是_______。
如果能用t检验处理的资料而用秩和检验,则缺点是
在华工作的A国公民汤姆不幸在中国南京市因车祸丧生,其在华留有动产,公告六个月内,除汤姆在A国的姐姐主张继承权外,无继承人申请继承,下面有关本案继承的说法中,哪些是正确的()。
下列诉讼活动符合有关规定的是:()
试回答下列关于色度、光度的问题。色度测量仪有()。
A期货公司取得金融期货结算业务资格后一直未取得期货交易结算会员资格,根据《期货公司金融期货结算业务试行办法》的规定,从该公司获得期货交易结算业务资格之日起( )内,如果还未取得期货交易所结算会员资格的,该期货公司的金融期货结算业务资格便自动失效。
学习完中国古代历史,探究小组的同学撰写了多篇历史小论文,下列论文的题目不准确的是()。
请在【答题】菜单下选择【进入考生文件夹】命令,并按照题目要求完成下面的操作。注意:以下的文件必须保存在考生文件夹下。文慧是新东方学校的人力资源培训讲师,负责对新入职的教师进行人职培训,其PowerPoint演永文稿的制作水平广受好评。最
最新回复
(
0
)