Asteroids, comets and meteors are hurtling through the solar system.

小行星、彗星和流星正快速地劃過太陽系。

So how do you tell them apart and which rocks could hit our planet?

所以你該如何分辨它們，而哪一種岩石可能會撞擊我們的星球呢？

Comets pass near Earth, but they never make it to the surface.

彗星掠過地球，但它們從來不會墜落在地球表面。

These cosmic snowballs form overtime in the outer reaches of the solar system and are made up of ice, rock and metal.

這些星際雪球在太陽系外生成，由冰、石頭和金屬組成。

If a comet gets too close to the sun, some of the ice heats up and turns into a gas, creating a glowy layer and that famous tail.

如果一顆彗星太靠近太陽，其中的一些冰會融化變成氣體，呈現出光亮的表層和那有名的尾巴。

If a comet were to shed its ice, it'd become an asteroid. Meh.

如果一顆彗星擺脫掉它的冰，它就會變成一顆小行星。不稀奇。

These space rocks can be as big as an entire country or as small as a chihuahua head.

這些宇宙岩石可以像一整個國家一樣大，或是像一隻吉娃娃的頭一樣小。

Most of the time, you can find them hanging out in the asteroid belt, a rocky superhighway between Mars and Jupiter.

大多時候，你可以在火星和木星之間的小行星帶，一個充滿岩石的超級高速公路找到它們的蹤跡。

Pieces of rock that break off asteroids and comets are called meteoroids.

從小行星和彗星剝落的碎狀岩石稱為隕石。

When a meteoroid enters the Earth's atmosphere, it burns up and causes friction that results in a light phenomena.

當一顆隕石進入地球的大氣層，它會燃燒殆盡並導致磨擦產生亮光的現象。

The streak of light is known as a meteor or a shooting star.

那道光線被稱為隕星或是流星。

And if a meteoroid lands on Earth's surface, ah runaway, it becomes a meteorite.

而如果一顆隕石墜落在地球表層，啊快跑，它就變成一顆隕星。

So the next time you're gazing at the sky and see a shooting star, you'll know exactly what it is and exactly what it isn't.

所以下次當你正看著天空且看到一顆流星時，你就會知道你看到的到底是甚麼和到底不是甚麼。

You can catch more episodes of Galactic Glossary every Wednesday, and to learn more about space rocks, like the one that triggered the demise of the dinosaurs, check out this video here.

你可以在每個星期三看到更多 Galatic Glossary 的節目，學到更多有關宇宙岩石的知識，像是導致恐龍滅亡的隕石，來看看這部影片吧！

Thanks for watching and let us know what you think in the comments below.

感謝收看並在下方留言區讓我們知道你的想法。