For one thing, it's not a perfect circle, it's quite an elongated ellipse.

至少不是一个标准的圆形，而更像是一个拉长的椭圆。

An ellipse is an asymmetrically shaped closed oval.

任何椭圆都是对称封闭的椭圆形。

Remember too that the Moon's orbit around the Earth is an ellipse.

同样要记住的是，月亮绕地球的公转轨道是个椭圆。

This ellipse has an important property called eccentricity.

椭圆有一个重要的性质，叫做离心率。

Eccentricity measures how flattened an ellipse is compared to a circle.

偏心率衡量的是椭圆与圆相比的扁平度。

As Kepler showed, the earth's orbit is an ellipse, with the sun at one of the two focal points.

就像开普勒曾指出的，地球的轨道是个椭圆，相对以太阳为中心绕起来的有个焦点。

As the planet orbits the star, it makes a big circle (or ellipse) .

当行星围绕恒星运行时，它会形成一个圆(或椭圆)。

Now, Newton predicted that the orbit of Mercury was an oval, or as scientists like to say " an ellipse."

牛顿预测的水星轨道是椭圆的，或者用科家惯用的词，“椭圆形”。

The further apart the foci are, the more squashed the ellipse is.

焦点距离越远，椭圆受到的挤压就越。

Not only that, the Moon orbits the Earth on an ellipse.

不仅如此，月球绕地球公转的轨道是椭圆形的。

It has two points, called foci, which act as a combined center for an ellipse.

它有个点，称为焦点，作为一个椭圆的联合中心。

Instead, they generally have a stretched version of a circle, which is technically called an ellipse.

相反，它们通常有一个圆形的拉伸公转，也就是椭圆。

Well, an ellipse is a shape that resembles a kind of squashed circle.

椭圆是一种类似于被压扁的圆的形状。

Well, a is the semi-major axis, or half the distance along the long axis of the ellipse.

a 是半长轴，或者说椭圆长轴的距离的一半。

Its foci are two points within the ellipse that describe its shape.

它的焦点是椭圆内描述其形状的个点。

Simply put, eccentricity tells how much the ellipse deviates from a perfect circle.

简单地说，离心率表示椭圆与正圆的偏离程度。

And b is the semi-minor axis, or half the distance along the short axis of the ellipse.

b 是半短轴，或者说椭圆短轴的距离的一半。

And as if they were cuboidal cells that got stretched tall, their nuclei also are stretched into an ellipse.

由于它们是立方体细胞，被拉伸得很高，它们的细胞核也被拉伸成椭圆形。

They are aligned in a rough ellipse.

它们排列成一个粗略的椭圆。

An ellipse with zero eccentricity would just be a regular old circle.

偏心率为零的椭圆就是一个普通的圆。