[ti:Jupiter’s Moon Europa May Be Top Candidate for Life] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.24]A fresh look at old data is giving scientists a new reason to consider Europa, [00:08.08]a moon orbiting the planet Jupiter, [00:11.14]as a leading candidate in the search for life beyond Earth. [00:16.20]The reason: evidence of water from the moon shooting into space. [00:23.96]NASA, the American space agency, noted an unusual shape [00:30.08]-- a bend -- in Europa's magnetic field in 1997. [00:36.68]That was the year when NASA's Galileo spacecraft passed close to the moon. [00:43.52]For a time, it was about 200 kilometers above the surface. [00:50.20]Scientists reported earlier this month on their reexamination of the Galileo data. [00:58.04]They now think this bend in the magnetic field could be explained [01:03.79]by an active geyser in an underground ocean. [01:08.08]The scientists believe the spacecraft traveled through a plume of water. [01:15.12]Elizabeth Turtle is a planetary scientist [01:18.63]with the Johns Hopkins University Applied Physics Laboratory. [01:24.00]She told reporters that Europa does have a lot of the qualities [01:29.52]that are necessary for life was we know it. [01:32.90]"There's water. There's energy. [01:37.20]There's some amount of carbon material. [01:41.28]But the habitability of Europa is one of the big questions [01:46.36]that we want to understand," said Turtle. [01:50.52]"And one of the really exciting things about detection of a plume [01:56.03]is that that means there may be ways that the material from the ocean [02:01.28]— which is likely the most habitable part of Europa [02:04.97]because it's warmer and it's protected ... [02:08.12]to come out above the ice shell," she added. [02:12.88]University of Michigan space physicist Xianzhe Jia led the latest study, [02:19.92]which was published in the journal Nature Astronomy. [02:24.60]The findings support other evidence of plumes from Europa, [02:29.52]whose ocean may contain two times as much water as all of Earth's oceans. [02:36.80]In 2012, NASA's Hubble Space Telescope [02:40.92]collected evidence of ultraviolet radiation which suggests a plume. [02:47.40]NASA will get a close-up look from a new spacecraft [02:51.76]as part of the space agency's Europa Clipper mission. [02:56.88]That spacecraft could be launched as soon as June 2022. [03:02.92]The agency says this could provide a chance to examine plumes [03:08.10]for signs of life from Europa's ocean, some of which may be microscopic. [03:15.12]Experts consider Europa to be among the top candidates for life in our solar system. [03:22.64]But it is not the only one. [03:25.32]For example, NASA's Cassini spacecraft examined plumes from Enceladus, [03:33.36]a moon of the planet Saturn. [03:36.19]The water from Enceladus's ocean contained hydrogen from hydrothermal vents, [03:43.92]an environment that may have given rise to life on Earth. [03:48.32]Europa is a little smaller than Earth's moon [03:53.32]. Its ocean is buried under about 15 to 25 kilometers of ice. [04:00.56]Experts believe the ocean itself to be anywhere from 60 to 150 kilometers deep. [04:09.20]I'm Pete Musto. [04:10.88]更多听力请访问51VOA.COM