Exploring Exo-Venuses with JWST

在过去的十年中，我们已经开始使用透射光谱技术来揭示系外行星大气的细节。当这颗行星在轨道上从它的母星星前面穿过时，一些星光通过大气层过滤，出现了任何吸收气体和气溶胶的指纹。目前，我们最有能力对具有氢氦大气层的高温气体巨行星进行研究，而较小的较冷的行星则是一个挑战。金星是太阳系中与地球在大小和质量上最相似的行星，但它的进化历史最终导致了一个令人难以置信的高温，酸性和不适合居住的世界。研究其他恒星周围的类金星行星将有助于我们理解这是如何发生的。

Over the last decade, we have started to uncover details of exoplanet atmospheres using the technique of transmission spectroscopy. When the planet crosses in front of its parent star during orbit, some of the starlight is filtered through the atmosphere, emerging with a fingerprint of any absorbing gases and aerosols that are present. Currently, we are most capable of doing this for hot, gas giant planets with hydrogen-helium atmospheres, and smaller, cooler planets present a challenge.Venus is the planet in the Solar System with the greatest similarity to Earth in terms of its size and mass, yet its evolutionary history has culminated in an incredibly hot, acidic and inhospitable world. Studying Venus-like planets around other stars will help us to understand how this might have happened.