VOA慢速英语2019 NASA观察员在“可居住区域”中发现了地球大小的世界（在线收听）

A NASA satellite has discovered an Earth-sized world within its star's "habitable" area -- where liquid water could possibly exist.

美国国家航空航天局（NASA）的一颗卫星在其“宜居”区域内发现了一个地球大小的世界-可能存在液态水。

The world is known as an exoplanet. This term is used for planets that orbit a star outside of our own solar system.

这个世界被称为系外行星。这个术语用于在我们自己的太阳系之外绕恒星运行的行星。

NASA's Transiting Exoplanet Survey Satellite, or TESS, made the discovery. TESS was launched in 2018 to expand on the work of earlier exoplanets that space telescopes had discovered. Exoplanets are hard for telescopes to identify; the bright lights of the stars they orbit can hide them.

NASA的过境系外行星测量卫星（TESS）进行了发现。 TESS于2018年发射，以扩展太空望远镜发现的早期系外行星的工作。系外行星很难让望远镜识别。它们绕轨道运行的恒星的明亮灯光可以将它们隐藏起来。

TESS contains four individual cameras that search for drops in light levels. This may be linked to planetary movements. Scientists then attempt to confirm the presence of worlds and try to estimate the size and orbit of the planets.

TESS包含四个用于搜索光线水平下降的单独摄像机。这可能与行星运动有关。然后，科学家试图确认行星的存在，并试图估计行星的大小和轨道。

The newly found planet, called "TOI 700 d," is about 100 light years away from Earth, NASA's Jet Propulsion Laboratory said. It is about 20 percent larger than Earth. TOI 700 d is one of three planets orbiting a star known as TOI 700.

美国宇航局喷气推进实验室说，新发现的行星“ TOI 700 d”距离地球约100光年。它比地球大20％。 TOI 700 d是绕着一颗称为TOI 700的恒星运行的三颗行星之一。

The discovery was announced during a recent meeting of the American Astronomical Society in Honolulu, Hawaii.

这项发现是在夏威夷檀香山举行的美国天文学会最近一次会议上宣布的。

Being in a star's habitable area means that a planet has temperatures that could permit liquid water to exist on the surface. Since water is necessary for life as we know it, the presence of liquid means it could possibly support life.

处于恒星的宜居区域意味着行星的温度可能使液态水存在于地表。正如我们所知，由于水是生命的必需品，因此液体的存在意味着水可以维持生命。

Astronomers have not yet been able to measure TOI 700 d's mass. Such measurements will be necessary to estimate whether it is a rocky planet like Earth, or a gassy one like Neptune.

天文学家尚未能够测量TOI 700 d的质量。这样的测量对于估计是像地球这样的岩石行星还是像海王星这样的气态行星是必要的。

Elisa Quintana is an astronomer at NASA's Goddard Space Flight Center in Greenbelt, Maryland. She told Nature magazine that few Earth-sized planets have been discovered in habitable areas. She says this makes the latest find "exciting."

艾丽莎·昆塔娜（Elisa Quintana）是位于美国马里兰州格林贝尔特（NASA）的美国宇航局戈达德太空飞行中心的一名天文学家。她告诉《自然》杂志，在可居住的地区几乎没有发现地球大小的行星。她说，这使最新发现“令人兴奋”。

Scientists say they confirmed the planet information using NASA's Spitzer Space Telescope. They have modeled the planet's possible environments to help support future observation activities.

科学家说，他们使用NASA的Spitzer太空望远镜确认了行星信息。他们对地球可能的环境进行了建模，以帮助支持未来的观测活动。

The modeling team for TOI 700 d is led by Gabrielle Engelmann-Suissa. She is a visiting research assistant at Goddard. She said in a statement that the modeling process is very important to help learn more about conditions on TOI 700 d as more data is collected.

TOI 700 d的建模团队由Gabrielle Engelmann-Suissa领导。她是戈达德大学的访问研究助理。她在一份声明中说，随着收集更多的数据，建模过程对于帮助了解有关TOI 700 d条件的更多信息非常重要。

"It's exciting because no matter what we find out about the planet, it's going to look completely different from what we have here on Earth," Engelmann-Suissa said.

Engelmann-Suissa说：“这令人兴奋，因为无论我们从地球上了解到什么，它看起来都将与地球上的东西完全不同。”

Another exoplanet discovery was also discussed at the Astronomical Society meeting. Scientists announced that TESS had found its first exoplanet orbiting two stars instead of one.

天文学会会议上还讨论了另一个系外行星发现。科学家宣布，TESS发现了它的第一颗系外行星绕两颗恒星运转，而不是一颗。

The planet is called TOI 1338 b, which lies about 1,300 light years away from Earth, NASA said. It is about seven times larger than Earth. That makes it between the sizes of Neptune and Saturn.

美国宇航局说，这颗行星叫做TOI 1338 b，距地球约1300光年。它大约是地球的七倍。这使其介于海王星和土星之间。

Astronomers have estimated that one of the planet's stars is about 10 percent more massive than our sun. The other star is cooler, less bright and only one-third of our sun's mass. The two stars orbit each other every 15 days.

天文学家估计，行星中的一颗恒星比我们的太阳重约10％。另一颗恒星更凉爽，亮度更低，仅为我们太阳质量的三分之一。两颗星每15天绕轨道运行一次。

These kinds of planets, called circumbinaries, are difficult to identify. So far, scientists have confirmed about 24 of them. The first such discovery came in 1993.

这类行星被称为外行星，很难辨认。到目前为止，科学家已经证实了其中的24种。第一次发现是在1993年。

Overall, more than 3,500 exoplanets have been discovered over the past 20 years.

在过去的20年中，总共发现了3500多颗系外行星。

重点词汇：

Words in This Story：

habitable – n. able to be lived in