Dwarf Planet Ceres Has Salty Ocean Deep Underground
Ceres is the largest object in the asteroid belt between the planets Mars and Jupiter. In a new study, scientists suggest this dwarf planet contains a large body of salty water under its cold surface.
The researchers describe Ceres as an "ocean world" - a place that could have the right conditions to support living organisms.
The study was released earlier this month in the publications Nature Astronomy, Nature Geoscience and Nature Communications.
The research is based on data gathered by NASA's Dawn spacecraft, which flew as close as 35 kilometers to the surface of Ceres in 2018. The study provides evidence that the dwarf planet remains geologically active with cryovolcanism - volcanoes that produce icy material.
The scientists say their findings confirm the presence of a reservoir of salty water below the surface that has been slowly freezing. Planetary scientist and Dawn lead investigator Carol Raymond told the Reuters news agency it is this finding that makes Ceres an ocean world, even though liquid does not cover the whole dwarf planet.
"In the case of Ceres, we know the liquid reservoir is regional scale but we cannot tell for sure that it is global. However, what matters most is that there is liquid on a large scale," Raymond said.
Ceres is about 950 kilometers around. The scientists centered their work on a 92-kilometer-wide crater formed when a large object hit Ceres about 22 million years ago. The crater has two bright areas caused by salt collections from liquid that reached the surface.
The scientists say the liquid started in a salt water reservoir hundreds of kilometers wide about 40 kilometers below the surface. When the large object crashed into Ceres, breaks in the dwarf planet's surface created openings for salty water to escape.
There are several other solar system bodies beyond Earth where there at least appear to be oceans below the surface. These include Jupiter's moon Europa, Saturn's moon Enceladus, Neptune's moon Triton and the dwarf planet Pluto.
Water is considered a major necessity for life. Scientists want to study whether Ceres was ever home to microbial life.
Planetary scientist Julie Castillo of NASA's Jet Propulsion Laboratory said there is major interest at this point in examining the possibility of life in Cerer's reservoir. That is especially true "considering it is cold and getting quite rich in salts," she added.
I'm Pete Musto.
谷神星地表下暗藏大片海洋
谷神星是火星和木星之间小行星带中最大的天体。在一项新的研究中，科学家们认为在这颗矮行星的寒冷表面下含有大量盐水。
研究人员称谷神星是一处“海洋世界”，一处有适当条件让生物生存的地方。
这项研究于本月初在《自然·天文学》、《自然·地球科学》和《自然·通讯》杂志上发表。
这项研究是基于美国宇航局“黎明号”航天器收集到的数据，该航天器于2018年飞到了距离谷神星表面最近只有35公里的地方。这项研究提供了证据，证明这颗矮行星在低温火山作用下仍然在地质上活跃。
科学家们表示，他们的研究结果证实了地表下有缓慢冻结的盐水层的存在。行星科学家、“黎明号”首席研究员卡洛尔·雷蒙德（Carol Raymond）告诉路透社，这一发现使得谷神星成为了一个海洋世界，尽管液体未能覆盖整颗矮行星。
雷蒙德表示：“就谷神星而言，我们知道这片盐水层是区域性的，但无法确定它是全球性的。但是最重要的是存在大规模的液体。”
谷神星直径大约有950公里。科学家们的工作主要集中在谷神星上一个大约2200万年前由大型物体撞击形成的92公里宽的陨石坑。这个陨石坑有两处明亮的区域，这是由到达地表的液体所携带的盐分聚集形成的。
科学家们表示，这种液体来自于地表以下大约40公里处的一片宽达数百公里的盐水层。当大型物体撞到谷神星时，这颗矮行星的表面裂缝，为盐水的溢出打开了出口。
在地球以外还有其它几个太阳系天体，至少在地表以下似乎是海洋。这些行星包括木星的卫星欧罗巴，土星的卫星土卫二，海王星的卫星海卫一以及矮行星冥王星。
水被认为是生命的重要必需品。科学家们想研究谷神星是否曾经有过微生物生命。
美国宇航局喷气推进实验室的行星科学家朱莉·卡斯蒂略（Julie Castillo）表示，目前人们非常有兴趣研究谷神星的水层是否有生命的可能性。她还说：“考虑到它温度很低，并且盐分含量非常高，这样做就尤为正确。”
皮特·穆斯托为您播报。
用户评论