Prometheus is the third of Saturn's known satellites:
orbit: 139,350 km from Saturn
diameter: 91 km (145 x 85 x 62)
mass: 2.7e17 kg
Prometheus was a Titan who stole fire from Olympus and gave it to humankind, for which Zeus punished him horribly; son of Iapetus; brother of Atlas and Epimetheus. "Prometheus" is Greek for "foresight".
Discovered by S. Collins and others in 1980 from Voyager photos.
Prometheus is the inner shepherd satellite of the F ring.
Prometheus has a number of ridges and valleys and several craters about 20 km in diameter but appears to be less cratered than the neighboring moons Pandora, Janus and Epimetheus.
From their very low densities and relatively high albedos, it seems likely that Prometheus, Pandora, Janus and Epimetheus are very porous icy bodies. (Note, however, that there is a lot of uncertainty in these values.)
The 1995/6 Saturn Ring Plane Crossing observations found that Prometheus was lagging by 20 degrees from where it should have been based on Voyager 1981 data. This is much more than can be explained by observational error. It is possible that Prometheus's orbit was changed by a recent encounter with the F ring, or it may have a small companion moon sharing its orbit.
Prometheus 是距土星第三近衛(wèi)星：
公轉(zhuǎn)軌道：距土星 139,350 千米
衛(wèi)星直徑：91 千米（145×85×62）
質(zhì)量：2.7e17 千克
Prometheus（普羅米修斯）是一位從奧林匹斯山偷走火種并把它帶到人間的巨人。就因為這，宙斯用殘忍的手段來懲罰他；他是Iapetus的兒子，Atlas和Epimetheus的兄弟。它在希臘語中意為“深思遠(yuǎn)慮”
它是被S. Collins和其他一些人于1980年從旅行者號傳回的照片中發(fā)現(xiàn)的。
土衛(wèi)十六是F光環(huán)中的一顆牧羊衛(wèi)星。
土衛(wèi)十六有許多山脈和山谷和一些直徑為20千米左右的隕石坑。但是看上去它的隕石坑比周圍鄰近的衛(wèi)星（土衛(wèi)十七，土衛(wèi)十和土衛(wèi)十一）少。
從它們很低的密度和相對較高的反照率來看，土衛(wèi)十六，土衛(wèi)十七，土衛(wèi)十和土衛(wèi)十一可能是多孔的冰質(zhì)天體。（注解：對于這些數(shù)值還有很多不能確定。）
根據(jù)1995年6月的土星光環(huán)平面交叉線觀察發(fā)現(xiàn)，土衛(wèi)十六比從旅行者號1981年數(shù)據(jù)算出的所在位置落后了20度，這是不足以用觀察誤差所能解釋的。可能土衛(wèi)十六的軌道最近與F環(huán)遭遇而發(fā)生改變或者他可能有一個小伴星與它一起分享這個軌道。
orbit: 139,350 km from Saturn
diameter: 91 km (145 x 85 x 62)
mass: 2.7e17 kg
Prometheus was a Titan who stole fire from Olympus and gave it to humankind, for which Zeus punished him horribly; son of Iapetus; brother of Atlas and Epimetheus. "Prometheus" is Greek for "foresight".
Discovered by S. Collins and others in 1980 from Voyager photos.
Prometheus is the inner shepherd satellite of the F ring.
Prometheus has a number of ridges and valleys and several craters about 20 km in diameter but appears to be less cratered than the neighboring moons Pandora, Janus and Epimetheus.
From their very low densities and relatively high albedos, it seems likely that Prometheus, Pandora, Janus and Epimetheus are very porous icy bodies. (Note, however, that there is a lot of uncertainty in these values.)
The 1995/6 Saturn Ring Plane Crossing observations found that Prometheus was lagging by 20 degrees from where it should have been based on Voyager 1981 data. This is much more than can be explained by observational error. It is possible that Prometheus's orbit was changed by a recent encounter with the F ring, or it may have a small companion moon sharing its orbit.
Prometheus 是距土星第三近衛(wèi)星：
公轉(zhuǎn)軌道：距土星 139,350 千米
衛(wèi)星直徑：91 千米（145×85×62）
質(zhì)量：2.7e17 千克
Prometheus（普羅米修斯）是一位從奧林匹斯山偷走火種并把它帶到人間的巨人。就因為這，宙斯用殘忍的手段來懲罰他；他是Iapetus的兒子，Atlas和Epimetheus的兄弟。它在希臘語中意為“深思遠(yuǎn)慮”
它是被S. Collins和其他一些人于1980年從旅行者號傳回的照片中發(fā)現(xiàn)的。
土衛(wèi)十六是F光環(huán)中的一顆牧羊衛(wèi)星。
土衛(wèi)十六有許多山脈和山谷和一些直徑為20千米左右的隕石坑。但是看上去它的隕石坑比周圍鄰近的衛(wèi)星（土衛(wèi)十七，土衛(wèi)十和土衛(wèi)十一）少。
從它們很低的密度和相對較高的反照率來看，土衛(wèi)十六，土衛(wèi)十七，土衛(wèi)十和土衛(wèi)十一可能是多孔的冰質(zhì)天體。（注解：對于這些數(shù)值還有很多不能確定。）
根據(jù)1995年6月的土星光環(huán)平面交叉線觀察發(fā)現(xiàn)，土衛(wèi)十六比從旅行者號1981年數(shù)據(jù)算出的所在位置落后了20度，這是不足以用觀察誤差所能解釋的。可能土衛(wèi)十六的軌道最近與F環(huán)遭遇而發(fā)生改變或者他可能有一個小伴星與它一起分享這個軌道。