The first asteroid ever discovered - Carrie Nugent

翻译人员: Nika Wang 校对人员: Jenny Yang

On the night of January 1, 1801,

1801年1月1日的夜晚，

Giuseppe Piazzi, a priest in Palermo, Italy,

意大利巴勒莫市 的神父朱塞普·皮亚齐

was mapping the stars in the sky.

正在记录天空中的繁星。

Over three nights, he'd look at and draw the same set of stars,

连续三个夜晚，他把观察到 的同一个星群画在纸上，

carefully measuring their relative positions.

并仔细测量它们的相对位置。

That night, he measured the stars.

第一晚，他做了一次测量。

The next night, he measured them again.

第二晚，他又测了一次。

To his surprise, one had moved.

令他惊讶的是，有颗星移动了。

The third night, the peculiar star had moved again.

第三晚，那颗奇异的星又移动了。

This meant it couldn't be a star at all.

也就是说那不会是颗恒星。

It was something new, the first asteroid ever discovered,

这是第一颗被人发现的小行星，

which Piazzi eventually named Ceres.

皮亚齐将它命名为谷神星（Ceres）。

Asteroids are bits of rock and metal that orbit the Sun.

小行星是环绕太阳的岩石与金属。

At over 900 kilometers across, Ceres is a very large asteroid.

谷神星直径超过900公里， 可说是巨型小行星。

But through a telescope, like Piazzi's,

但从望远镜看去，正如皮亚齐所见，

Ceres looked like a pinpoint of light similar to a star.

谷神星只是一个小亮点， 和其他恒星一样。

In fact, the word asteroid means star-like.

其实，asteriod (小行星) 这个词的意思就是“如恒星般”。

You can tell the difference between stars

从星体在空中移动的方式

and asteroids by the way they move across the sky.

就可以分辨出恒星和小行星。

Of course, Piazzi knew none of that at the time,

当然，皮亚齐当时并不知道这些。

just that he had discovered something new.

他只晓得自己有了个新发现。

To learn about Ceres,

要了解谷神星，

Piazzi needed to track its motion across the sky

皮亚齐需要记录它在空中移动的位置，

and then calculate its orbit around the Sun.

然后计算出其环绕太阳的轨道。

So each clear night, Piazzi trained his telescope to the heavens.

所以，在每个月朗星稀的夜晚， 皮亚齐都会用望远镜观察星空。

Night after night, he made careful measurements

每一晚，他都会仔细测量，

until finally, he couldn't.

直到有一天他再也无法计算。

The Sun got in the way.

因为太阴阻挠了他的观察。

When Piazzi first spotted Ceres, it was here, and the Earth was here.

皮亚齐首次发现谷神星时 它就在这里，地球在这边。

As he tracked it each night, the Earth and Ceres moved like this

随着每晚的记录， 地球和谷神星会这样移动，

until Ceres was here.

直到谷神星移到了这里。

And that meant that Ceres was only in the sky when it was daytime on Earth.

这表示，谷神星只有在白天才会出现。

During the day, bright sunlight made this small asteroid impossible to see.

但明亮的阳光 让人很难看见这颗小行星。

Astronomers needed to calculate Ceres's orbit.

天文学家需要计算谷神星的轨道，

This would let them predict where it was going to be

以预测谷神星每个夜晚的

in the vast night sky on any given night.

运行路线。

But the calculations were grueling and the results imprecise.

但计算轨道十分劳神，结果也并不准确。

Many astronomers searched for Ceres,

许多天文学家都在寻找谷神星，

but not knowing exactly where to look, no one could find it.

但却不晓得该从何处找， 所以没人能找到。

Luckily, a hardworking mathematician named Carl Friedrich Gauss

幸好，一名叫高斯的勤奋数学家

heard about the lost asteroid.

听说了此事。

He thought it was an exciting puzzle and went to work.

他想解开这有趣的谜题。

When he realized he didn't have the mathematical methods he needed,

当他发现自己没有所需的数学方法时，

he invented new ones that we still use today.

他发明了一个新的方法，沿用至今。

He derived a new orbit and new predictions of where to look for Ceres.

他推演出一套新方法 来测定谷神星的轨道。

Hungarian astronomer Baron Franz Xaver von Zach

匈牙利天文学家 弗朗茲·冯·扎克男爵

searched for Ceres with Gauss's predictions.

用高斯的轨道测定法来寻找谷神星。

After weeks of frustrating clouds,

熬过几周乌云密布的夜晚后，

von Zach finally had clear skies on December 31, 1801.

在1801年12月31日晴朗的夜空中，

He looked through his telescope and finally saw Ceres.

他终于从望远镜中看见谷神星了。

We haven't lost track of it since.

自那之后，谷神星的踪迹 便一直在我们的掌握中。

Today, we've discovered hundreds of thousands of asteroids.

如今，我们已经发现了 数十万颗小行星。

Many, including Ceres, orbit the Sun between Mars and Jupiter,

包括谷神星在内的许多小行星 都在火星和木星间绕着太阳转，

while near-Earth asteroids orbit the Sun relatively close to Earth.

近地小行星环绕太阳 的轨道也离地球更近。

When we recorded this narration,

录制这段旁白的时候，

astronomers had discovered 16,407 near-Earth asteroids,

天文学家已发现了 16407颗近地小行星，

but since we find new asteroids all the time,

由于新的小行星不断被发现，

that number will have grown by hundreds or thousands

在你观看这段视频的时候，这个数字

by the time you watch this.

可能已经多出了几百，甚至几千。

Today, asteroid hunters use modern telescopes,

今天，寻找小行星的人 使用现代望远镜，

including one in space.

其中包括空间望远镜。

Computers analyze the images,

这些影像由电脑分析，

and humans check the output

通过人工检查结果，

before reporting the asteroid observations to an archiving center.

最后再将小行星的观察报告 送至归档中心。

Each discovered asteroid has its unique orbit measured.

针对每颗被发现的小行星， 我们都有独特的方法来测量其轨道。

An orbit lets astronomers predict where asteroids are going to be

该轨道可让科学家预测

at any given time.

小行星在任何时间的走向。

大多数测定的小行星轨道 准确度可以持续80年，

Most asteroid trajectories can be predicted for about 80 years

though we can calculate where the best studied asteroids will be every day

但对于那些详尽研究的小行星，

between now and 800 years into the future.

我们甚至可计算其未来 800年的每日运行轨道。

We must keep searching for asteroids

虽然如此，我们还是要

in case there's one out there on a collision course with Earth.

不断寻找新的小行星， 以免它们撞上地球。

Astronomers don't only search for asteroids, though.

天文学家要做的不止如此。

They also study them to learn how they formed,

他们也要研究小行星， 了解它们如何形成，

what they're made of,

由什么元素构成，

and what they can tell us about our solar system.

以及它们和太阳系的关系。

Today, we can do something that Piazzi could only dream of:

今天，我们能做到 皮亚齐无法完成的事：

send spacecraft to study asteroids up close.

把宇航飞船送到太空 近距离观察小行星。

One spacecraft called Dawn journeyed billions of kilometers

一艘名为“黎明号”的宇航船 飞了几十亿公里，

over four years to the main asteroid belt.

用四年多的时间进入小行星带。

There, it visited Ceres and another asteroid, Vesta.

它在那里观察了谷神星 和另一颗小行星，灶神星。

Dawn's stunning images transformed Piazzi's dot of light

黎明号拍出的动人照片 将皮亚齐当时看见的光点放大为

into a spectacular landscape of craters,

令人惊艳的陨石坑，

landslides,

滑坡

and mountains.

和山峦。