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
54
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.
The main task of the Kepler space telescope is to find out planets with similar conditions to Earth’s.
选项
A Right
B Wrong
C Not mentioned
答案
A
解析
第二段最后一句话“…on hunting planets that might have conditions similar to those on Earth”明确指出了这一点,因此题干的说法是正确的。
转载请注明原文地址:https://ti.zuoweng.com/ti/hp9QKKKQ
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-sizedplanets...
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanets...
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanets...
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanets...
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanets...
SoMany“Earths” TheMilkyWay(银河)containsbillionsofEarth-sizedplanets...
随机试题
东坡居士苏轼有可能与下列哪一名句的作者一起推杯换盏、吟诗作对()。
开放性损伤早期处理最重要的是
《义务教育数学课程标准(2011年版)》对课程总目标从四个方面进行了阐述,请问是
以下说法符合安全运动条件的是( )。
可以引起视神经炎的药物是
人是一种在本能与理想、欲望与价值的冲突中求取()的动物,本能与欲望是()的,
据美国汽车业的一项调查,一个满意的顾客会引发8笔潜在的生意,其中至少有一笔成交;
属于饱和脂肪酸的是A:棕榈油酸B:亚油酸C:棕榈酸D:二十二碳六烯酸E:α-亚麻酸
甲国人李某长期居住在乙国,并在乙国经营一家公司,在甲国则只有房屋出租。在确定纳税居民的身份上,甲国以国籍为标准,乙国以住所和居留时间为标准。根据相关规则,...
资产评估的( )主要有来自委托人和产权持有人的风险、来自评估对象的风险、来自资产评估报告使用中的风险等。A.经营风险B.业务风险C.财务风险D