Scientists believe that the Oort cloud is the source of many comets.

科学家们认为奥尔特云是许多彗星的来源。

The existence of the Oort cloud was first proposed by Dutch astronomer Jan Oort.

奥尔特云的存在最早是由荷兰天文学家扬·奥尔特提出的。

The Oort cloud is thought to be a spherical shell surrounding the solar system.

奥尔特云被认为是围绕太阳系的一个球形壳。

The Oort cloud remains one of the most mysterious regions of our solar system.

奥尔特云仍然是我们太阳系中最神秘的区域之一。

Some comets from the Oort cloud can take thousands of years to complete an orbit.

一些来自奥尔特云的彗星可能需要数千年才能完成一个轨道。

The hypothetical planet—or companion of the Sun—would be located in the outer part of the Oort cloud.

这颗假设行星（或太阳的伴星）应该位于奥尔特云的外围。

I believe it is likely that this is because the Oort Cloud is being disturbed by a massive body that is throwing comets out of stable orbits, a small fraction of which could reach the Earth.

我认为这可能是因为奥尔特云受到一个正在把彗星抛出不变轨道的大天体的扰动，其一一小部门彗星可能会达到地球。

The Oort Cloud is thought to extend about 1 light year from the Sun.

欧特云团距太阳1光年距离。

Our solar system is surrounded by a vast collection of icy bodies called the Oort Cloud.

我们的太阳系被一大片冰体物质所包围，这就是所谓的欧特云团(Oort Cloud)。

Their theory was that the orbit of this star every 26 million years moved into an area called the Oort cloud and dislodged comets that then pounded the earth.

他们的理论是，这颗星星的轨道每隔2600万年都会进入奥尔特星云所在的区域，从而激发该处的彗星冲击到地球上。