Placeholder Image

字幕表 動画を再生する

  • Water is vital to life on Earth and probably to life elsewhere.

  • This has led astronomers to become interested in oceans.

  • And to the discovery that oceans can be very different to those beneath the open skies of Earth.

  • On three of the moons of Jupiter,

  • and two of the moons of Saturn,

  • there was good evidence of liquid oceans.

  • The first of these oceans to be discovered was within Jupiter's moon Europa.

  • Though Europa is small, it may boast more liquid water than the Earth.

  • The ocean could be over 100 kilometers deep.

  • Heat generated by Jupiter's powerful tides keeps it warm underneath the icy shell.

  • Europe's Jupiter Icy Moons Explorer mission, or JUICE, will launch in 2022 to study Jupiter and three of its largest moons.

  • Perhaps one of the most promising oceans for study is on Enceladus, a tiny moon of Saturn.

  • This is because the ocean does not stay under the ice cap.

  • Geysers at the moon's south pole shoot ocean water hundreds of kilometers out into space.

  • Studies by NASA's Cassini probe showed that

  • the water in these jets contain organic molecules,

  • the building blocks of life.

  • There is also evidence of hydrothermal vents at the bottom of the ocean.

  • This is significant because it is thought that life first arose at hydrothermal vents on Earth.

  • A spacecraft flying through the jets of Enceladus

  • could sample the water for traces of complex

  • biological molecules such as DNA or protein.

  • There is no guarantee of life in the waters of Enceladus.

  • Or in any of the solar system's other hidden oceans.

  • But the possibility that something might be there will drive ambitious explorations for decades to come.

  • Coming up, how to discover new planets.

Water is vital to life on Earth and probably to life elsewhere.


動画の操作 ここで「動画」の調整と「字幕」の表示を設定することができます

B1 中級

宇宙での海探し|エコノミスト (The hunt for oceans in space | The Economist)

  • 193 6
    Jerry Liu に公開 2021 年 01 月 14 日