VOA慢速英语2019 美国宇航局的卫星发现了“第一颗超级地球”（在线收听）

NASA Satellite Discovers ‘First Nearby Super-Earth’

Researchers say they have discovered the first nearby “super-Earth” planet that could possibly support life.

研究人员表示，他们发现了首个可能可以维持生命的近距离“超级地球”。

The discovery was made by a spacecraft designed to look for planets outside of our solar system. An international team of astronomers recently announced their findings in the publication Astronomy & Astrophysics.

这个超级地球由在太阳系外寻找行星的航天器发现。最近，一个国际天文学家小组在《天文学和天体物理学》期刊上宣布了他们的发现。

The new discovery is known as an exoplanet, a planet that orbits a star outside of our own solar system. Exoplanets are not easy to identify with telescopes. This is because they are often hidden by the bright light of the stars they orbit.

这颗新发现的行星被称为太阳系外行星，即在太阳系外围绕一颗恒星运转的行星。太阳系外行星难以用望远镜发现。这是因为它们通常隐藏在其所环绕运行的恒星的强光之下。

In an effort to help discover such planets, NASA launched its Transiting Exoplanet Survey Satellite, or TESS, last year. TESS was designed to expand upon the work of previous exoplanet discoveries made with telescopes. More than 3,500 new exoplanets have been discovered over the past 20 years.

去年，美国国家航空航天局（简称NASA）发射了凌星系外行星巡天卫星（简称TESS），目的是为发现这类行星提供帮助。凌星系外行星巡天卫星旨在扩大此前用望远镜发现的太阳系外行星的工作。过去20年来，人类发现的太阳系外行星超过3500颗。

What is a super-Earth?

什么是超级地球？

A super-Earth is a planet that has a mass between one and 10 times that of Earth. The team of astronomers says the newly-discovered exoplanet – called GJ 357 d - is about 31 light-years away from our solar system. The planet orbits a star named GJ 357.

超级地球指质量是地球1到10倍的行星。天文学家团队表示，最新发现的太阳系外行星名为GJ 357 d，距离太阳系约31光年。该行星围绕名为GJ 357的恒星运行。

NASA said in an announcement that the planet appears to orbit within its star’s “habitable zone.”

NASA在声明中表示，这颗行星似乎位于其恒星的宜居带内。

A leading member of the research team was Diana Kossakowski from the Max Planck Institute for Astronomy in Heidelberg, Germany. She said in a statement that GJ 357 d should be receiving about the same amount of energy from its star as Mars does from the sun.

该研究团队的主要成员是来自德国海德堡麦克斯普兰喀天文机构的戴安娜·科萨克沃斯基。她在声明中表示，GJ 357 d从其恒星那里接收的能量应该与火星从太阳接收的能量大致相同。

“If the planet has a dense atmosphere, which will take future studies to determine, it could trap enough heat to warm the planet and allow liquid water on its surface,” Kossakowski said.

科萨克沃斯基表示，“这颗新发现系外行星是否有浓密的大气层还需要未来研究加以确定，但如果有，它就能收集足够的热量，使行星变暖，并允许液态水在其表面流动。”

NASA says the planet’s mass is at least 6.1 times Earth’s and it orbits its star every 55.7 days.

NASA表示，该行星的质量至少是地球的6.1倍，每55.7天绕其恒星公转一周。

Lisa Kaltenegger is an associate professor at New York’s Cornell University. She is also a member of the TESS science team. Kaltenegger called the new discovery “exciting.”

莉萨·卡尔特内格尔是纽约康奈尔大学的副教授。她也是TESS科学团队的成员。卡尔特内格尔称这一新发现“令人振奋”。

“This is TESS’s first discovery of a nearby super-Earth that could harbor life,” she told the university’s Cornell Chronicle. “TESS is a small, mighty mission with a huge reach,” she said.

她对康奈尔大学的《康奈尔纪事》说，“这是TESS发现的首个可能存在生命的近距离超级地球。”她表示，“TESS是虽小但伟大的任务，它已经取得了巨大的成功。”

Kaltenegger added that the discovery will provide valuable information about this and other large exoplanets outside our solar system. “With a thick atmosphere, the planet GJ 357 d could maintain liquid water on its surface like Earth, and we could pick out signs of life with telescopes that will soon be online,” she said.

卡尔特内格尔还指出，这项发现将提供有关这颗行星及其他大型太阳系外行星的有价值信息。她说，“如果有浓密的大气层，GJ 357 d行星就能像地球一样在其表面保持液态水，我们可以通过即将上线的望远镜来寻找生命迹象。”

NASA says TESS observed the GJ 357 star system last February. Researchers estimated the star is about one-third the mass of our sun. Several other exoplanets were discovered in the system after being caught by TESS cameras.

NASA表示，TESS在去年2月勘测到GJ357恒星系统。研究人员估计，该恒星的质量大约是太阳的三分之一。在TESS配备的相机捕捉到该系统之后，已有多颗系外行星被发现。

One of those exoplanets was identified as GJ 357 b, a planet 22 percent larger than Earth, the astronomers reported. It orbits 11 times closer to its star than Mercury does to our sun. GJ 357 b is thought to have surface temperatures up to 254 degrees Celsius.

天文学家报告称，其中一颗系外行星是GJ 357 b，其体积比地球大22%。该行星围绕恒星运行的轨道比水星绕太阳的运行要近11倍左右。据估计，GJ 357 b的表面温度高达254摄氏度。

GJ 357 b is considered a “hot Earth,” said Enric Pallé, a lead member of the discovery team with the Institute of Astrophysics of the Canary Islands.

加那利群岛天体物理学研究所发现小组的重要成员恩里克·帕莱表示，GJ 357 b被认为是“热地球”。

Pallé noted that the planet could not hold life. But it is “one of the best rocky planets we have for measuring the composition of any atmosphere it may possess,” he added.

帕莱指出，该行星不能维持生命。他说，“但这是我们发现的其中一个最佳岩质行星，使我们得以测量其可能存在的大气层的成分。”

Jack Madden is a student at Cornell University who helped with the research on GJ 357. He says the new discoveries have opened the door for astronomers to test theories and models about exoplanets.

杰克·马登就读于康奈尔大学，他为GJ 357的研究提供了帮助。他表示，新发现为天文学家打开了大门，让他们可以测试与系外行星有关的理论与模型。

“We built the first models of what this new world could be like,” Madden said. “Just knowing that liquid water could exist on the surface of this planet motivates scientists to find ways of detecting signs of life.”

马登说，“我们构建了这个新世界可能面貌的首批模型。仅仅是知道这个行星表面可能存在液态水就能激励科学家去寻找探测生命迹象的方法。”

Words in This Story

habitable – adj. able to be lived in

light-year –n. (unit of measure) the distance light travels in one year

determine – v. discover the facts or truth about something

harbor – v. to be the home or habitat of

maintain – v. make a situation or activity continue

composition – n. the parts that something consists of

possess – v. to have or own something

motivate – v. to cause someone to behave a particular way

detect – v. to discover or notice something