字幕列表 影片播放 列印英文字幕 The search for extraterrestrial life extends into the far reaches of our galaxy and while several distant exoplanets are strong candidates to maybe host life, what if the most promising destination is right in our celestial backyard? The perfect conditions for alien life, might just be hidden under the icy crust of Jupiter’s moon, Europa, and since it’s in our solar system, we can actually go to it. A new mission from NASA just got the green light to proceed with building an in-depth, investigative orbiter named Europa Clipper. This will be the first time we send a spacecraft to a moon other than our own, and perhaps, uncover that we might not be alone in the universe. So NASA has reason to believe that Europa is potentially habitable because of the information they’ve received from the Hubble Space Telescope, and from previous space missions. These spacecraft weren’t destined for Europa, but they took measurements of the moon’s surface while passing by. It was from one of these flybys that the strongest piece of evidence of Europa’s ocean emerged. The Galileo mission measured a deep magnetic field that could only be produced by an electrically conductive fluid under the moon’s 15 to 25 kilometers thick icy layer. Scientists estimate, even though the moon is 10% smaller than our own, the predicted salt water ocean underneath could be twice the volume of all of Earth’s oceans combined. Now, life as we know it needs at least three requirements: liquid water, the right chemical elements, and an energy source. So while this icy world probably has water, and possible elements, it’s been hard to nail down an energy source on Europa, but NASA’s orbiter is prepared to find it. The Europa Clipper’s payload will be stocked with nine different instruments. Each built by researchers across the U.S. and curated by NASA specifically for this mission. Some of the equipment are systems like cameras and spectrometers that aim to map and produce high-resolution images. But other specialized machinery includes a dual-frequency radar instrument that can penetrate the thickness of Europa’s icy shell in search for subsurface lakes—like the ones found in Antarctica. There will also be a magnetometer device and a plasma instrument that together, will measure Europa’s magnetic field and the ocean’s depth and salinity. And even more tools will be searching for water plumes erupting from the moon’s surface, and will be able to detect even tiny water particles in the atmosphere. These droplets might be connected to the hidden subsurface ocean. Every instrument onboard is designed to paint a detailed picture of the moon’s composition from the surface to the atmosphere, without actually landing on it. In fact, the spacecraft won’t be orbiting Europa at all. The moon sits within one of Jupiter’s intense bands of radiation. And although Clipper is armed to withstand some radioactive emissions, it wouldn’t last more than a few weeks around Europa. Instead, the orbiter will be using Jupiter’s gravitational pull to loop around Europa on 45 close flybys. Some as close as 25 kilometers. Now, just to be clear, at the very least, if scientists do find life, they are expecting it to be most likely in the form of tiny microbes. Maybe similar to the extremophile creatures we have on Earth that thrive in subterranean volcanoes, deep-sea vents, or arid deserts. There could be something more complex to find, but at the moment, there’s a bigger hurdle still facing this mission; how will it get there? According to NASA, the Europa Clipper remains on target for a launch between 2023 and 2025. The question is whether it will fly on NASA’s Space Launch System rocket, which may not be ready in the next few years, or if it will ride atop a commercial rocket, like SpaceX’s Falcon Heavy or United Launch Alliance's Delta IV Heavy. But commercial options lead to more travel time in space, which Clipper might not be ready for. Timelines aren’t matching up and the politics are still murky for this pivotal mission, which makes the anticipation all the more nail-biting. Because of the challenges of distance and radiation, paired with the enormously tantalizing idea of finding life beyond Earth, Europa Clipper is maybe one of the most ambitious missions ever attempted by NASA. We still have some years before anything is leaving the ground, but we’ll be keeping a watchful eye on this mission that could change our perspective of life in the universe forever. Europa Clipper is exciting, so exciting in fact that people are pushing to send a lander next! But we’ll have to get there first. If you want more launch updates in your day, check out the Countdown to Launch playlist here and subscribe to Seeker for all your rocket needs. Thanks for watching and I’ll see you next time.
B2 中高級 美國宇航局計劃如何在木星的月球上發現外星生命,歐羅巴|發射倒計時。 (How NASA Plans to Discover Alien Life on Jupiter’s Moon, Europa | Countdown To Launch) 8 0 林宜悉 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字