字幕列表 影片播放 列印英文字幕 You may have heard that it's not smart to look directly at the Sun, and that's for good reason—it's pretty bad for you. But it turns out that stars can be problematic in a similar way when we're looking out into space: their glare can stop us from seeing the stuff we want to see. But NASA's shiny new tool just might let us see more worlds, in more detail, than ever before. These overly-bright stars are pesky because we're looking for exoplanets, or planets outside of our own solar system. And NASA's Wide-Field Infrared Survey Telescope is expected to help us add thousands more exoplanets to our database. But first we're going to have to solve the problem of the stars that these exoplanets orbit. The way the telescope 'sees' these planets is essentially by recording the photons that bounce off of them. These relatively faint signals have to compete with the extreme brightness of the star itself. So WFIRST is essentially going to have to cancel out billions of photons from the star for every single photon that they want to capture of the planet that we actually want to see. We're gonna need a pretty big pair of sunglasses for that task—or maybe more accurately, starglasses. That incredibly sophisticated pair of starglasses is actually called a coronagraph. It's an additional instrument that will travel with the telescope, and it allows us to see beyond the bright glare of stars in a really clever way. Some simpler coronagraphs just use a dark, opaque piece of glass to block out the bright light coming directly from the star—kinda like your sunglasses do. But WFIRST's more sophisticated coronagraph consists of a few complex light-blocking steps, including a pair of “deformable mirrors,” or mirrors that are flexible and can change shape. In reaction to tiny errors that may crop up as the telescope operates, these mirrors can be deformed by hundreds of tiny actuators that manipulate them into different shapes and configurations, filtering out the light from star. And this manipulation of the mirrors is so precise they can fix errors smaller than the width of a strand of DNA. This precision lets us see the finer details of the planets we're looking at. WFIRST will be the third NASA mission to carry coronagraph technology, and will probably be two to three orders of magnitude more powerful than any coronagraph that's ever flown in space before. It could let us see some crazy stuff, like star systems as they're just beginning to form, which could help us understand how ours might have come to be. And it'll help us see way more exoplanets in general— about 2,500 of them, some of which will be rocky planets in the habitable zone, where liquid water could exist, which you know, could host life, no big deal! That's one hell of a pair of starglasses. WFIRST will launch in the mid-2020s, and its coronagraph has already passed an important milestone. It's been through a design review, which means that it's met all of its design requirements on budget and on schedule, which is a huge feat. That means that now, NASA scientists and engineers get to actually start building it! I think one of my favorite parts of this project is that after WFIRST launches and has proven itself over its first 18 months, use of the telescope and its data will be totally open to the scientific community. That means that scientists around the world will be able to submit proposals for work on the telescope. Which is important because WFIRST isn't just looking at exoplanets— it will also observe and take measurements that may help us learn more about dark energy and infrared astrophysics. WFIRST and its sophisticated spectacles will be in space for at least five years, and will blaze a trail for a clearer view of space. These innovations will also guide and influence coronagraph technologies for even more advanced missions in the future, allowing open science to peer further into space and see in more detail than ever before. For more on exciting space tech developments, check out this video here, and make sure you subscribe to Seeker to keep up with all of your telescopic news. Let us know what other space-peering advancements you want us to cover down in the comments down below, and as always—thanks so much for watching.
B1 中級 美國宇航局的WFIRST太空望遠鏡將提供一個前所未有的宇宙觀 (NASA’s WFIRST Space Telescope Will Offer an Unprecedented Look at the Universe) 2 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