该行星轨道的方向不断变化。

The orientation of the planet's orbit is changing continuously.

科学家仔细察看行星照片，寻找生命迹象。

Scientists are studying photographs of the planet for signs of life.

其他行星上有生命吗？

Does life exist on other planets?

哪些行星可以维持生命的存在？

Which planets can sustain life?

土星是太阳系中的第二大行星。

Saturn is the second biggest planet in the solar system.

这颗行星可能正环绕着一颗小恒星运行。

The planet is probably in orbit around a small star.

这幅图标示了太阳系八大行星中的6颗。

The picture shows six of the eight planets in the solar system.

新发现的行星大约是地球的10倍那么大。

The new planet is about ten times the size of the earth.

行星躲过超新星爆发的几率总是十分渺茫。

The chances of a planet surviving a supernova always looked terribly slim.

一颗不为人知的行星被命名为“祝融”。

The name Vulcan was given to the undiscovered planet

1664年，胡克注意到这颗行星表面有一块微红的斑点。

In 1664 Hooke observed a reddish spot on the surface of the planet.

在我们自己的星系里可能有数以万计的行星系。

Within our own galaxy there are probably tens of thousands of planetary systems.

新发现的这个天体具有不同于任何其他行星的运行轨道。

The newly discovered world followed an orbital path unlike that of any other planet.