首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
So Many “Earths” The Milky Way (银河)contains billions of Earth-sized planets ...
So Many “Earths” The Milky Way (银河)contains billions of Earth-sized planets ...
admin
2020-12-24
52
问题
So Many “Earths”
The Milky Way (银河)contains billions of Earth-sized planets that could support life. That’s the finding of a new study. It draws on data that came from NASA’s top planet-hunting telescope.
A mechanical failure recently put that Kepler space telescope out of service. Kepler had played a big role in creating a census of planets orbiting some 170,000 stars. Its data have been helping astronomers predict how common planets are in our galaxy. The telescope focused on hunting planets that might have conditions similar to those on Earth.
The authors of a study, published in The Proceedings of the National Academy of Sciences, conclude that between 14 and 30 out of every 100 stars, with a mass and temperature similar to the Sun, may host a planet that could support life as we know it. Such a planet would have a diameter at least as large as Earth’s, but no more than twice that big. The planet also would have to orbit in a star’s habitable zone. That’s where the surface temperature would allow any water to exist as a liquid.
The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them. The scientists used those numbers to extrapolate (推算)to the rest of the stars that the telescope could not see.
The estimate is rough, the authors admit. If applied to the solar system, it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars. Neither planet is Earthlike (although either might have been in the distant past). Using tighter limits, the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world. These are ones that would take 200 to 400 days to complete a yearly orbit.
Four out of every 100 sunlike stars doesn’t sound like a big number. It would mean, however, that the Milky Way could host more than a billion Earth-sized planets with a chance for life.
This is the first research finding about the planets with a chance for life.
选项
A Right
B Wrong
C Not mentioned
答案
C
解析
全文均未提到是否为 “the first research finding”。
转载请注明原文地址:https://ti.zuoweng.com/ti/5p9QKKKQ
相关试题推荐
20Theheartcontainsthebody’sstrongestmuscle.ARightBWrongCNotmentio
20Theheartcontainsthebody’sstrongestmuscle.ARightBWrongCNotmentio
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanet...
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanet...
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanet...
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanets...
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanets...
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanets...
EtaCarinae Aspossiblythegalaxy’s(银河)mostmassivestar,EtaCarinaeis...
EtaCarinae Aspossiblythegalaxy’s(银河)mostmassivestar,EtaCarinaeis...
随机试题
在《担保法》规定的五种担保方式中,既允许债务人用自己的财产也可以用第三人财产向债
根据我国《合同法》,要约生效的时间为( )。
依据辅助设施验收细则规定,脉冲电子围栏及入侵报警装置验收中前端设施的验收标准是(
主要用于控制症状的抗疟药有() A.氯喹 B.伯氨喹 C.奎宁 D.
某杂志记者未经核实,就报道某明星在公共场所打架斗殴,袭击前来处理事情的警察,该明
甲某贩运假烟,驾车路过一个检查站,检查人员朱某正要登车检査时,甲某突然发动汽车
下列具有自律性的心肌细胞为 A-心房肌细胞B.心室肌细胞C.乳头肌细胞D.心内膜细胞E.窦房结
按照《建设工程项目管理规范》(GB/T50326-2006),下列区域中风险等级最高的是()。A.风险区AB.风险区BC.风险区CD.风险区D
当供求曲线移动时,下列可引起均衡价格変化不确定的情形有()A.需求曲线和供给曲线同时向右移动B.需求曲线和供给曲线同时向左移动C.需求曲线向右移动而供给曲线
某种运输服务价格变动引起另一种运输服务供给量变动的灵敏程度用()来反映。A:运输需求派生弹性B:运输供给派生弹性C:运输供给交叉弹性D:运输需求交叉弹性