Nearby planet is 'excellent' target in search for life
附近的行星是搜索外星生命的“极好的”目标
Astronomers have found a cool, Earth-sized planet that's relatively close to our Solar System.
天文学家发现了一个离太阳系相对接近的冷温，类似地球大小的行星。
The properties of this newly discovered planet - called Ross 128 b - make it a prime target in the search for life elsewhere in the cosmos.
这个新发现的叫做Ross 128 b行星的特性使它成为人类寻找宇宙中有生命的其他地方的首要目标。
cosmos：n.宇宙;
At just 11 light-years away, it's the second closest exoplanet of its kind to Earth.
离地球仅仅11光年的距离，它是同类行星中的第二个最接近地球的外星。
light-year：光年
But the closest one, known as Proxima b, looks to be less hospitable for life.
但最接近地球的是个被称为比邻星 b，似乎不太适合生命的存活。
Proxima：比邻星
Found in 2016, it orbits the star Proxima Centauri, which is known to be a rather active "red dwarf" star. This means that powerful eruptions periodically batter Proxima b with harmful radiation.
这个发现于 2016年的行星运行轨道是围绕着比邻星半人马座，这是一个众所周知的、相当活跃的、 "红矮星" 的恒星。这意味着比邻星 b周期性的受到它强大的有害辐射的喷发。
red dwarf：红矮星
radiation：辐射
The new planet, Ross 128 b, orbits a star that's not dissimilar to Proxima Centauri (it's also a red dwarf), but is significantly less active.
这颗新行星, Ross 128 b，绕着一颗与比邻星半人马座并非不同的恒星 (它也是一个红矮星)，但它的活跃程度明显较低。
The new world was discovered with the High Accuracy Radial velocity Planet Searcher (Harps) instrument at the La Silla Observatory in Chile. The work will be published in the journal Astronomy & Astrophysics.
这个新的世界是用位于智利的 La Silla观测所的高精度径向速度行星搜索器 (Harps) 发现的。这个研究将发表《天文学和天体物理学》杂志上。
At 1.35 times the mass of our planet, Ross 128 b is a bit heftier than Earth and orbits 20 times closer to its star than we orbit the Sun. But because the new planet's parent star is much smaller and dimmer than our yellow sun, it receives only a little more solar radiation than Earth.
Ross 128 b是我们地球质量的1.35 倍, 比地球更重一些，它的运行轨道离它围绕的恒星比我们绕太阳的运行轨道近20倍。但是, 因为新行星的母恒星比我们的黄色太阳小得多，暗的多，Ross 128 b 受到的太阳辐射仅比地球多一点。
Consequently, it is expected to have a surface temperature close to that on our own planet.
因此，它的表面温度预计接近我们自己的星球。
consequently：结果
In the search for habitable worlds beyond our Solar System, astronomers generally look for low-mass, rocky and temperate planets like ours.
在寻找我们太阳系以外的可居住的世界时，天文学家通常会寻找像我们这样的低质量（密度）、多岩石的并且温度缓和的行星。
At "just" 4.2 light-years away, Proxima b may be the closest exoplanet with a mild temperature. But it receives about 30 times more extreme ultraviolet radiation than Earth. Ross 128 b, on the other hand, is the "quietest" nearby star to host a temperate exoplanet.
在 "仅仅" 4.2 光年之外，比邻星 b 可能是最接近地球的温度缓和的外行星。但它接收的极端紫外线辐射比地球高出30倍。而Ross 128 b则是 地球附近"最安静的" 母恒星的一个温和的外行星。
Astronomers often talk about the "habitable zone" around a star - it's the range of distances where temperatures allow water (essential for life as we know it) to remain liquid on the surface of a planet.
天文学家经常谈论围绕一颗恒星的 "可存活区"--这就是温度能够允许水在行星表面保持液态 (我们所知道的生命所必需的) 的距离范围。
Where the habitable zone lies depends on the star itself: red dwarfs are dimmer and therefore cooler than the Sun, so their habitable zones are shifted closer in than the equivalent zone in our Solar System.
可存活区的位置取决于恒星本身: 红矮星比太阳更暗，因此其温度更低，因此它们的可居住区比我们太阳系中的等效区域更接近。
There's still uncertainty about whether Ross 128 b is within its star's habitable zone, but scientists say that with temperatures of between -60 and +20°C, it can be considered temperate.
Ross 128 b 是否在其恒星的可存活区域内仍然存在不确定性，但科学家说，温度介于-60 和20° c 之间，可以认为是温和的。
temperate：（气候） 温和的;
But a lot depends on the presence of an atmosphere. An envelope of greenhouse gases can warm the surface and provide sufficient pressure to keep water in the liquid state.
但很大程度上取决于大气层的存在。一个温室气体的保护层可以温暖表面，并提供足够的压力，以保持液态水的状态。
Next, astronomers want to study the atmospheric composition and chemistry of suitable, nearby worlds like Ross 128 b. The detection of gases such as oxygen could potentially point to biological processes.
接下来, 天文学家想研究像Ross 128 b这样的合适并临近的星球的大气成分和化学。如果像氧气等气体被检测存在的话，这可能会意味着有生物过程的存在。
Although currently 11 light-years from Earth, the new planet's parent star Ross 128 is moving towards us and is expected to overtake Proxima Centauri as our nearest stellar neighbour in just 79,000 years - a heartbeat on cosmic timescales.
虽然目前距地球11光年, 新行星的母星Ross128正在向我们移动, 预计在短短的7.9万年后就会超过比邻星半人马座而成为我们最近的恒星邻居-在宇宙的时间轴上，这只是心跳一般的短暂。
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