媒體英語會帶大家一起學習BBC撰稿人在報道世界大事時常用到的單詞和短語。

Background: 天文學家發現了能滿足人類生存條件的行星，并稱此行星和太陽系外已發現的所有行星相比，其特征更近似于地球。

Gliese 581g is the sixth planet to be found circling a dwarf star some 20 light-years away, in the constellation of Libra.

On paper it looks good – three times the mass of the Earth with possibly a rocky surface and enough gravity to hold on to an atmosphere.

The researchers also promised shirt-sleeve weather in some regions, but not everywhere. One side of the planet is almost always in sunshine; the other almost always in darkness. And estimated temperatures range from minus four degrees Celsius to a very hot 71 degrees.

A year meanwhile would go by in just 37 days.

Of course, whether life could be supported on Gliese 581g would need much more investigation and most probably technologies which don't exist yet. But the astronomers say that planethunting is getting easier and they were surprised how quickly they detected the tell-tale signs of this distant body using ground-based telescopes.