感謝收聽,期待你對本期節(jié)目的評論留言哦～ Science and technology Oceans in space Not so lonely sea in the sky Pluto[’pl?to]冥王星 is the latest place thought to have subsurface['s?bs??f?s]地下的 waters. Is the solar system about to get another ocean? So far, besides Earth, six bodies are known or suspected to harbour藏匿 oceans. These are Europa[ju?'r?up?]木衛(wèi)二, Callisto[k?'list?u]木衛(wèi)四 and Ganymede木衛(wèi)三['ɡ?nimi:d] (all moons of Jupiter['d?u?p?t?]木星), Enceladus[en'sel?d?s]土衛(wèi)二 and Titan[ta?tn]土衛(wèi)六 (both moons of Saturn['s?t(?)n]土星) and Triton ['tra?tn]海衛(wèi)一(a moon of Neptune[?neptju:n]海王星). The latest candidate is Pluto, the most famous inhabitant[?n'h?b?t(?)nt]居住者 of the Kuiper belt柯伊伯帶, a girdle['g??d(?)l]帶 of asteroids ['?st?r?idz]小行星that orbit ['??b?t]繞軌道運行the sun beyond Neptune. Pluto’s claim to an ocean, argued this week in two papers published in Nature, is based on data collected in 2015 by New Horizons, a robotic[r???b?t?k]自動的 spacecraft航天器 that zoomed[zu?m]急速上升 past it in July of that year. The ocean in question, if it exists, is beneath在......下方 Pluto’s surface. That makes it unlike Earth’s ocean, but like those of the other six bodies. To human sensibilities that is,perhaps, a funny sort of ocean. But add it to the other six and it is Earth’s surface ocean that looks anomalous[?'n?m(?)l?s]異常的, rather than Pluto’s buried one. The argument for a Plutonic[pl?'tɑn?k] ocean—advanced by teams led by Francis Nimmo of the University of California, Santa Cruz,and James Keane, of the University of Arizona[,?ri'z?un?]亞利桑那州,Tucson['tu:s?n]（城市名）, centres on Sputnik['sp?tn?k] Planitia史潑尼克平原，a basin['be?s(?)n] 盆地1,300km across ,caused by a collision[k?'l??(?)n]碰撞 in Pluto’s distant past.Pluto and its largest moon, Charon['k?r?n], are tidally潮水似地 locked. As they orbit their common centre of gravity, they always show each other the same face and, relative to the horizon, the position in the sky of either observed from the other never changes. The curiosity is that Sputnik Planitia lies almost exactly on the opposite side of Pluto from Charon, on the “tidal axis[??ks?s]軸線”, a line that runs through the centre of both bodies. That is quite a coincidence[k??'?ns?d(?)ns]—or, rather, in Dr Nimmo’s view it isn’t. He calculates the odds of it happening by chance as one in 20. He would therefore prefer to believe there is a physical explanation. And there might be. If Sputnik Planitia were an anomalously dense part of Pluto’s surface,and thus a concentration of mass[m?s] 質量, it would affect Pluto’s orientation with respect to its moon. That would cause Pluto to topple['t?p(?)l]傾倒 over until Sputnik Planitia lay atone[?'t??n]彌補 of the two points at which the tidal axis intersects[?nt?'sekt]相交 its surface. Unfortunately, basins are characterised以......為特征 by the absence of mass rather than its presence. But Dr Nimmo is unfazed[,?n'fe?zd]不苦惱的. He suggests that the huge quantities of material blasted out by the impact which created Sputnik Planitia would have reduced the pressure on Pluto’s crust[kr?st] 地表, letting the subterranean[,s?bt?'re?n??n]地下的 water of a hypothetical[?ha?p??θet?kl]假想的ocean bulge[b?ld?]凸出closer to the surface. Since water is denser than most of the stuff found at or near Pluto’s surface, that upwelling 上升流would have increased the relative mass of Sputnik Planitia rather than decreasing it. Though speculative['spekj?l?t?v]推測的, this idea is plausible['pl??z?b(?)l]貌似可信的. Water is common in the Kuiper belt,and Pluto in particular is thought to consist of a rocky core巖核 overlain[,?uv?'lein]放在......上面 by a thick mantle['m?nt(?)l]覆蓋of ice. That rocky core will contain radio active有輻射的 elements, the decay[d?'ke?]衰減 of which might provide enough heat to melt some of the mantle. Add a dash[d??]沖撞 of ammonia[??m??ni?]氨氣, also common on Pluto, to lower the water’s freezing point, and Presto['prest??]轉眼間! You have an ocean. 歌曲:Fuckin' perfect----P!nk