行星定义

他还说，其他天文学家想把行星定义为像地球一样受自引力作用呈球状的星体。

He said other astronomers want to define planet as round , like Earth , due to self-gravity .

国际天文学会对行星重新定义，剥夺了冥王星的地位。

Astronomers'reclassification strips ninth planet of status in solar system .

克罗斯维尔认为，我们对行星的定义应当简化，即行星是一种周期性围绕太阳旋转的星体，其直径不应小于冥王星的直径。

Croswell believes we should define a planet simply – as something that goes around the sun and has the diameter of Pluto or more .

两名天文学家于周三通报，他们发现了令人信服的迹象，表明存在一颗更大、更遥远的天体——该星体将满足目前对行星的定义，而冥王星则不符合。

Two astronomers reported on Wednesday that they had compelling signs of something bigger and farther away - something that would satisfy the current definition of a planet , where Pluto falls short .

国际天文学联合会在行星的新定义中将轨道作为一项衡量标准。

The new IAU planet definition mentions orbits .

行星的新定义不单是科学问题，也是社会问题。

The definition of planet is not only a science issue , but also a social issue .

首先，让我们重温国际天文联会通过有关太阳系行星的新定义。

First of all , let us look at the approved IAU definition of a planet in our solar system .

他说如果这颗行星真的存在，它应该能轻易吻合对行星的定义。

If the planet exists , it would easily meet the definition of planet , Dr. Brown said .