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The NASA telescope that can find alien life (Seeker)
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https://multimedia-english.com/videos/esl/the-nasa-telescope-that-can-find-alien-life-seeker-6952
Description


- Exciting news that James Webb Space Telescope got its first snapshot of an exoplanet. It was a ground-breaking picture that we've all been waiting to see, and it looks like this.


Okay, I know what you're thinking, but first let me just say that this is really cool.


This is HIP 65426 b. It's a young gas giant around 355 light years away, but the casual observer it's, I don't know, kind of fuzzy… like I guess that's a planet.


The thing is, as amazing as JWST is, it will never give us an image of an exoplanet that’s like, well this.


This is one of the most detailed images of earth ever taken. You can see land masses, oceans, clouds, clear indicators that the planet can harbour life.


So, how do we get from something like this, closer to this?


Well, a team at NASA has been tasked with a potential mission that could be a big step in that direction.


A mission that could potentially answer the question.


Are we alone?


- A reality is that no current instrument and instrument that we will have in the future will be able to bring us direct images of the exoplanets.


- Now, yes, this picture from JWST is a direct image, but one, it's of a gas giant, and two, it looks like this, that’s not what we're talking about. We're talking about a direct image of a smaller earth-like exoplanet with lots and lots of detail.


JWST can't do that. We've made some pretty big telescopes in the past, but to get the picture we're talking about, the size of the lens you would need would be hard to pull off.


- If I take our own earth, the diameter of our earth is about 13,000 kilometres, and I move that object to 100 light years away.


If I want to image that exoplanet with just one pixel, I need to have access to a telescope of about 90 kilometres in diameter.


- So let's see, a 90 kilometre telescope that’s about 55 miles. So, just the distance from New York City to Bridgeport, Connecticut, or Los Angeles to San Bernardino or… look, you get it. It's just too big for a telescope lens, and that's just for a one pixel image.


- Let's say 10 pixels, I must have 900 kilometre telescope.


- So, Slava and his team turned to a lucky quirk of physics to solve this problem.


- Solar gravitational lens is the only way for us to start seeing those exoplanets directly before we will be able to travel to those distant floors.


- Okay. Gravitational lens is really cool but can be hard to understand. So, let's do this.


Now, to witness this phenomenon, you need three things. A distant object like an exoplanet, something with a lot of mass, like a star, and then you need something looking back at these two things in a straight line, like a telescope.


Perfect.


Oh, none of this is to scale, by the way, nothing in this video is to scale. So what are you gonna do?


Okay. The most important thing you have to know is that light can bend or refract. So, put a straw and a glass of water, and hey, there you go, light has been bent.


Your glasses also bend light in case your eyeballs are doing a lousy job of it on their own. Lenses can also magnify stuff if it's a convex lens, so you know that kind of bulges out.


Basically, you just need something to bend light like glass or water or space-time.


You see, space time can be curved by the gravity of something massive like the star. This curve in space time is like a convex lens, so when light from a distant object hits this curve, it bends around it and is then magnified by a lot. But  think of it like really, really strong reading glasses.


Now, if we're able to look directly at this huge object through a telescope, as the light bends around it from just the right angle, we’ll see that light in the shape of a ring known as an Einstein ring.


- And that Einstein ring essentially has all the lights from Luminous source.


- In other words, all the information we need to create a picture of a planet.


Now, it's tricky to catch sight of an Einstein ring since everything has to be positioned perfectly relative to the observer.


You have to be looking at say, a galaxy with another galaxy behind it, and then be far enough away from everything that you're at the point where all the light rays converge.


Tricky, but you can actually game plan for all these, if you know those positions in advance. Which is exactly Dr. Turyshev and his team's plan.


You find an exoplanet, you get a telescope, then you use the sun as your massive body to bend the light. A light from the exoplanet bends around the sun creating an Einstein ring that.


- That hold the lights from luminous source.


- And remember, we've magnified that light. So now, instead of a fuzzy image.


- We can form an image of that exoplanet within 1000 by 1000 pixel image. And so that means we will be able to see continental lines, weather patterns, topography, ice caps.


- So continents, oceans, deserts.


It also means hypothetically, we’d be able to see the light from cities at night, which would be proof of intelligent life somewhere else in the universe.


But look at that ring. How do we construct a high-resolution image out of that? That does not look like a planet.


Well, the idea is that you don't just take one picture. The telescope would take many many pictures of the ring at slightly different angles, recording the difference in brightness each time. Then when we get those images back on earth, we can assemble a clear image using a method called deconvolution.


Now that sounds crazy, well, it's similar to how NASA made this image from before. This isn't just one shot of earth like the original Blue Marble taken from Apollo. It's months of light data collected by a satellite that was then stitched together.


Now, the resolution here is obviously greater and the execution is slightly different, but I mean, it's earth, we're here. The basic idea, though, is the same. Sounds great, right?


So, where do we put this thing thing? Well, that's the tricky part.


- We need to reach the region of roughly 550 AU away. It still takes time.


- Which is slightly farther than Los Angeles to San Bernardino.


You see, in order to actually view the Einstein ring, that telescope has to be far back enough, so that it falls into a sweet spot, which starts roughly 82 billion kilometres away.


And unfortunately, current propulsion technology can’t get us to that distance in a reasonable amount of time, which Dr. Turyshev determines to be 25 to 35 years, so within the career of a scientist. That's why Dr. Turyshev is looking at solar sales as a way to get that added power.


We're not there yet, but solar sales are already being used, and put to the test in other missions.


Once you get there, though, you’ve got all the time in the world to take pictures as long as you travel along the sweet spot or focal plane, if we wanna be technical. Well, I mean, until the satellite stops working.


That's also for the best, as your telescope is only ever gonna image that one exoplanet.


You see repositioning the telescope just a single degree to see another target, would involve moving at the distance of earth to Saturn.


Okay, I can't sit like this anymore.


But here's another cool part, these are just one meter telescopes. So while other telescopes like JWST identify more and more exoplanets, we can send out more and more of these small cube set telescopes to the right sweet spots to see them. So, both telescopes get to do with each two best. Nice.


- Initially, I thought it was a science fiction, totally unrealizable, and now I think it's rather feasible. We have not found a showstopper. For the last 5,000 years, people would go on the steady night and would wonder, are we alone? Is there life? And so that's something that we can do with the solar gravitational lens, and which is something excites me, and something that actually drives my life recently for the last five years.


- Now, this all sounds awesome. You're right. It is.


And yes, look, this is still in the research phase and no launches are planned, but that's no reason to not get excited.


And let's go back to the original Blue Marble that was taken in 1972. If this mission develops in the way Dr. Turyshev and his team hopes, we could have our first image of an exoplanet that looks like this by the 2060s, less than 100 years later. Let's hope we get to see it.


-  Do you need help?


-  I'm okay.


-  I feel like she would kind of wanna just see how the sausage gets made.


-  Absolutely not.