张明波

在太阳系中，除了地球之外，人类至今还没有发现一个与地球“一模一样”并且具有适合居住条件的星球。最近，美国国家航空航天局（NASA）官宣发现“第二地球”，人类真的可以移居到“第二地球”吗？

The planet， called TOI 700 d， was discovered by NASAs TESS ， and is one of only a few Earth?sized planets discovered in a stars habitable zone.

Paul Hertz， astrophysics division director at NASA Headquarters in Washington， D.C.， said，“TESS was designed and launched specifically to find Earth?sized planets orbiting nearby stars. Planets around nearby stars are easiest to follow up with larger telescopes in space and on Earth.”

“Discovering TOI 700 d is a key science finding for TESS.” The planet orbits a small， cool star called TOI 700， which is located just over 100 light years away from Earth. The star is roughly 40% of the Suns mass and size， and about half its surface temperature.

Several planets appear to orbit the star. The innermost planet， TOI 700 b， is a rocky planet thats almost exactly the same size as Earth， while the middle planet， TOI 700 c， is 2.6 times larger than Earth， and is a gas?dominated world.

Finally， the outermost planet， TOI 700 d， is the only one in the habitable zone， and is around 20% larger than Earth.

To confirm the planets sizes and compositions， NASA used its Spitzer Space Telescope. While TOI 700 ds exact conditions are unknown， the researchers used 3D climate models to predict its surface type and atmospheric composition.

One model suggests that the planet may be ocean?covered with a dense， carbon?dioxide?dominated atmosphere， while an other indicates that TOI 700 d could be an all?land version of modern Earth.

The researchers hope that further data on the planet will help to work out which of these models is correct.

Gabrielle Engelmann?Suissa， a universitiy space research association visiting research assistant at Goddard， added，“Someday， when we have real spectra（光谱） from TOI 700 d， we can backtrack， match them to the closest simulated spectrum， and then match that to a model. Its exciting because no matter what we find out about the planet， its going to look completely different from what we have here on Earth.”

[阅读检测]

1. Whats the main task of TESS？

A. To look for civilization from outer space.

B. To find Earth?sized planets in space.

C. To guarantee the Earth is in a safe state.

D. To provide scientists with more models.

2. What is TOI 700 b mainly made of？

A. Rocks.

B. Gas.

C. Soils.

D. Water.

3. How did Gabrielle Engelmann?Suissa feel about the possible findings of TOI 700 d？

A. Worried.

B. Proud.

C. Excited.

D. Upset.

[语言学习]

难句分析

While TOI 700 ds exact conditions are unknown， the researchers used 3D climate models to predict its surface type and atmospheric composition. 虽然TOI 700 d的确切情况尚不清楚，但研究人员使用3D气候模型来预测它的表面类型和大气成分。

【点石成金】本句是一个主从复合句。While引导让步状语从句，主句的主语是 the researchers，主句中的to predict its surface type and atmospheric composition为不定式短语作目的状语。