找回密码
 注册
查看: 3559|回复: 35
打印 上一主题 下一主题

Astronomers strip Pluto of its status as a planet天文学家取消冥王星行星地位

[复制链接]

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

1#
发表于 2006-8-25 08:42 |只看该作者
With one vote, toys and models of the solar system became instantly obsolete, forcing teachers and publishers to scramble to update textbooks and lessons used in classrooms for decades.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

2#
发表于 2006-8-25 08:43 |只看该作者
Discovered in 1930 by the American Clyde Tombaugh, the icy rock of Pluto has traditionally been considered the ninth planet, farthest from the sun in the solar system.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

3#
发表于 2006-8-25 08:44 |只看该作者
However, the definition of a planet, approved after a heated debate among 2,500 scientists from the International Astronomical Union (IAU) meeting in Prague, drew a clear distinction between Pluto and the other eight planets.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

4#
发表于 2006-8-25 08:45 |只看该作者
The scientists agreed that, to be called a planet, a celestial body must be in orbit around a star while not itself being a star.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

5#
发表于 2006-8-25 08:46 |只看该作者
It must be large enough in mass for its own gravity to pull it into a nearly spherical shape and have cleared the neighborhood around its orbit.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

6#
发表于 2006-8-25 08:47 |只看该作者
Pluto was disqualified because its oblong orbit overlaps Neptune's. Xena also does not make the grade of being a planet, and will also be known as a dwarf planet.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

7#
发表于 2006-8-25 08:49 |只看该作者
The agreed-upon definition -- the first time the IAU has tried to define scientifically what a planet is -- comes in sharp contrast to the draft sent around to delegates at the General Assembly last week.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

8#
发表于 2006-8-25 08:51 |只看该作者
The new definition creates a second category called "dwarf planets," as well as a third category for all other objects, except satellites, known as small solar system bodies.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

9#
发表于 2006-8-25 08:52 |只看该作者
From now on -- or 'at least for the time being' joked one delegate -- traditional planets will be restricted to eight: Mercury, Venus. Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

10#
发表于 2006-8-25 08:53 |只看该作者
It's an issue mainly for the public, not really for scientists.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

11#
发表于 2006-8-25 08:56 |只看该作者
Officials at the American Museum of Natural History in New York had been at the vanguard of the movement to demote Pluto and were feeling vindicated on Thursday.
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

12#
发表于 2006-8-25 09:01 |只看该作者
请冷玉将此贴移至书院
NIMBUS

291

主题

0

好友

1万

积分

版主

Rank: 7Rank: 7Rank: 7

13#
发表于 2006-8-25 09:07 |只看该作者
书院帖子可以慢慢浏览,潜心细读
聊作无益之事,以遣有涯之生

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

14#
发表于 2006-8-25 09:11 |只看该作者
来自世界各地的天体物理学家在布拉格投票,取消冥王星的地球第九大行星资格,原因是它按照新的行星定义,不具备围绕一颗形体运转的独立的运行轨道(他与海王星的轨道交叉重叠,没有依靠自身的质量形成绕太阳旋转的独立轨道),而且其直径很小,质量不大
NIMBUS

115

主题

0

好友

7670

积分

终极会员

Rank: 8Rank: 8

15#
发表于 2006-8-25 09:13 |只看该作者
这样,太阳系便只剩下八大行星。课本和科普文章都得重新修订。从小知道太阳系有九大行星的我们也必须改变观念了
NIMBUS
您需要登录后才可以回帖 登录 | 注册

手机版|Archiver|长安新城

GMT+8, 2024-12-23 01:12 , Processed in 0.057269 second(s), 18 queries .

Powered by Discuz! X2.5

© 2001-2012 Comsenz Inc.

回顶部