Where you can learn more about how planets are actually discovered

在這裡你可以瞭解更多關於行星是如何被發現的。

The first 200 people to click on the link in the description will get 20% off of an annual premium subscription

前200名點擊描述中的鏈接的人將獲得年度高級訂閱的8折優惠。

So based off the demographics of people that watch my videos

所以根據看我視頻的人的人口統計數據

Chances are that most of you learned at school at some point that the solar system contains 9 planets

很有可能你們大多數人都在學校學過 太陽系有9顆行星

Mercury, Venus, Earth, Mars, Saturn, Jupiter, Uranus, Neptune, and Pluto.

水星、金星、地球、火星、土星、木星、天王星、海王星和冥王星。

In 2006, the Internation Astronomical Union removed Pluto from this list and reclassified it as a dwarf planet.

2006年，國際天文學聯盟將冥王星從這一名單中刪除，並將其重新歸類為一顆矮行星。

Which lowered the count of planets in the solar system to 8, and has disappointed Pluto fans ever since.

這讓太陽系的行星數量降到了8顆，從此讓冥王星迷們失望了。

So from 2006 on, school curriculum in the United States and elsewhere has taught that the solar system just contained 8 planets.

所以從2006年開始，美國和其他地方的學校課程都在講太陽系剛好包含8顆行星。

But, it may actually have been 9 all along. It just wasn't ever Pluto.

但是，其實可能一直都是9號。只是從來沒有冥王星。

In 2016, 2 researchers up at California Institute of Technology came to a startling conclusion based off of mathematical and computational models.

2016年，加州理工學院的2名研究人員根據數學和計算模型得出了一個驚人的結論。

These models suggested that a huge and undiscovered planet may exist in the far regions of the solar system.

這些模型表明，在太陽系的遙遠區域可能存在一顆巨大的、未被發現的行星。

If this turns out to be true, the model suggests that the planet has about 10 times the mass of Earth and about 2-4 times Earth's diameter, making it roughly the same size as the planet, Neptune.

如果結果是真的，該模型表明，這顆行星的品質約為地球的10倍，直徑約為地球的2-4倍，是以它的大小與海王星大致相同。

Neptune is only an average of 30 AU's from the sun. 1 AU, meaning the distance between Sun and Earth. Pluto, meanwhile is usually 40 AU's from the sun, while Planet 9 if it exists, would be located an average of 700 AU's from the sun.

海王星距離太陽的平均距離只有30AU。1AU，意味著太陽和地球之間的距離。同時，冥王星距離太陽通常為40AU，而9號行星如果存在的話，其距離太陽的平均距離為700AU。

In fact, this entire planet's orbit is crazy to think about. It would take between 10 thousand and 20 thousand years for it to make one complete orbit around the sun. This means that at it's closest point it would still be 200 AU's away. The furthest into space we've ever made so far is with the Voyager 1 space probe.

其實，這整顆行星的軌道想起來都很瘋狂。它需要1萬到2萬年的時間 才能繞著太陽轉一圈這意味著在它最接近的地方 它仍有200AU的距離．到目前為止，我們進入太空最遠的一次是旅行者1號太空探測器。

And even then, that has only traveled 139 AUS as of August 2017.

而即便如此，截至2017年8月，也只走了139澳元。

Since planet 9 so far has not yet been observed directly, the only evidence for it's existence are mathimatical.

由於9號行星至今還沒有被直接觀測到，所以它存在的唯一證據就是數學上的。

But, they're pretty convincing. thirteen of the most distant known hyperbelt objects for example all have

但是，它們很有說服力。 例如，13個已知的最遙遠的超帶天體都有。

Orbits that line up in a very peculiar way.

以一種非常奇特的方式排列的軌道。

The clustering of orbits like this is extremely unlikely to have happened just by chance,

這樣的軌道集群，極不可能只是偶然發生。

But the existence of planet 9 could easily explain it.

但9號行星的存在很容易解釋。