| Astronomers looking at Hyperion, a large Saturn moon, say the spud -shaped rock has a "sponge-like appearance" unlike anything ever seen. |
天文學(xué)家們研究了土星的大型衛(wèi)星—土衛(wèi)七后指出，該衛(wèi)星形狀似土豆，表面象海綿，跟以往發(fā)現(xiàn)的天體均不相同。 |
| As much as 40% of Hyperion could be porous, according to research led by Dr Peter Thomas of the Center for Radiophysics and Space Research at Cornell University published today in the journal Nature. |
康乃爾大學(xué)電波物理與太空研究中心的彼得·托馬斯主持研究了土衛(wèi)七。今天發(fā)表在《自然》雜志上的研究成果表明，多達(dá)40%的土衛(wèi)七表面為多孔地形。 |
| The US space probe Cassini sent back high-resolution images of Hyperion to Earth in four flybys in 2005 and 2006. In its closest pass, it swooped to within 618 kilometres of its surface, getting picture resolution as fine as a few kilometres across. |
在2005和2006年，美國(guó)航天探測(cè)器“卡西尼號(hào)”四次飛近土衛(wèi)七，發(fā)回了高分辨率圖象。“卡西尼號(hào)”飛過土衛(wèi)七時(shí)，跟其表面最靠近的一次相距不到618公里，所得圖象的分辨率不亞于相距幾英里時(shí)的拍照。 |
| "The most striking visual aspect of Hyperion is its sponge-like appearance, which is unlike any other object imaged to date," they report. |
研究人員報(bào)道：“土衛(wèi)七最顯著的視覺特征是其類似海綿的外表，這跟以前 所獲得的任何天體的圖象都不相同。” |
| Hyperion is peppered with craters, most of which are 2-10 kilometres across, and are well preserved.The apparent reason for this is that the surface is so porous that an impacting space rock causes little ejecta, material blasted out of the collision site and is scattered all around. |
土衛(wèi)七猶如遭到彈雨襲擊一般布滿隕石坑，多數(shù)隕石坑口徑為2至10公里，至今仍保存完好。形成這種情況的一個(gè)明顯原因就是土衛(wèi)七表面如此千瘡百孔，撞擊到上面的太空巖石不會(huì)激起內(nèi)部物質(zhì)從撞擊地點(diǎn)飛散到周圍。 |
| The moon has a mean diameter of 270 kilometres, but its shape is so irregular that this can be 190-364 kilometres. |
土衛(wèi)七的平均直徑為270公里，但因形狀很不規(guī)則，其直徑可能會(huì)從190至364公里不等。 |
| It is the eighth-largest satellite and the largest irregularly-shaped satellite of the 48 named Saturnian moons. Hyperion's strange shape may have been caused by bombardment by meteors, which blew away part of its surface, some experts believe. |
土衛(wèi)七是土星的第八大衛(wèi)星，也是土星已命名的48個(gè)衛(wèi)星中最大的形狀不規(guī)則衛(wèi)星。一些專家認(rèn)為，土衛(wèi)七的奇形怪狀是由于流星的襲擊撞飛了部分表面而造成的。 |
| In a companion paper, Dr Dale Cruikshank of NASA's Ames Research Center and colleagues report that Hyperion's surface is quite reflective but the bottoms of the craters are quite dark, similar to those found on the Saturnian moons Phoebe and Iapetus. |
在一篇相同主題的論文中，美國(guó)航空航天局艾米研究中心的戴爾·克魯克香克博士及同事報(bào)道，土衛(wèi)七表面反光性相當(dāng)好，但隕石坑的底部很黑暗，類似在土衛(wèi)九和土衛(wèi)八上發(fā)現(xiàn)的隕石坑。 |
