John Mulchaey discusses why collecting more light matters for detailed studies of exoplanet atmospheres. He describes the Giant Magellan Telescope's ambitions and the engineering involved in building a much larger ground-based instrument. The comparison with James Webb focuses on the difficulty of obtaining faint planetary signals, rather than suggesting that the two telescopes have identical capabilities.
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18:21than one of the mirrors of this one of the seven mirrors of this telescope. And we hit a limits with James Webb. I mean, you know, they're doing exoplanet work, it's super exciting. We have many Carnegie scientists trying to do atmospheres with James Webb. It's just not a very big telescope. >> Wow. >> this telescope will allow you to really get the the high-quality spectra we need to to study those exoplanet atmospheres. >> That's right. Yeah. I mean, we were here about two or three weeks ago when we were filming for the Henrietta episode, and one of the things that was striking to me is just how small that signal is >> Yeah. >> of an atmosphere >> Right. >> of a star, because the star is just blinding you, >> Absolutely. >> and then the atmosphere just comes in, and like it's it's really the the circle
19:02around a tiny dot with a with a giant flashlight in your face. Um and and so, I guess the the feature of the Giant Magellan Telescope being so big is that because you the signal is just so much higher, you can actually do that signal to noise. >> That's right. >> manage it. >> Yeah, and you'll get really high quality spectra. So, you know, most of the James Webb stuff that's happening now, a lot of them are pretty big planets. For the most part, I think they're they're big they're bigger than Jupiter in many cases, right? And that's simply because it's a small telescope. It's not small compared to, you know, 100 years ago Hubble would have thought that was an amazing >> It's still an amazing telescope. >> But in space, I know. The idea is is remarkable. >> Yeah, he would have been >> I mean, it's it's a crazy It's still an amazing telescope,
19:43but it's hitting its limit. They're really You can't really do the deep sort of spectroscopy that one needs to do. And for that, you just need a lot of photons. And it's all about collecting area. And so, that's where something like the GMT will really be very super. And And the interesting thing other thing about the GMT is the GMT's first light instruments are very, very centered on this exoplanet question. >> Oh, okay. >> So, we have a two instruments that are being built, one in the infrared and one in the optical, to do those atmospheres in extreme detail. So, it's going to be super exciting. And you're going to be able to just be able to do many, many more exoplanets. Right now, we're kind of limited to a small number that you can actually effectively do, you know, from James Webb. And this is one of the things Henry is trying to do, of course, at a different scale. Can we
20:25do it from the ground in general? With the GMT, it should be possible, no question, I think. >> Yeah. And I mean, this thing is massive. So, you're saying like 80 ft across? >> 80 ft across. 22 stories high is the dome. That's what I always like to give people I have a picture I don't know if you've seen me. We can share with you the picture of of it in the in the Rose Bowl, which is great for us. Those of us in Los Angeles. Absolutely, we'll show that cuz that's a really amazing picture, which I get every time I give a talk about GMT. It it it make it dwarfs the Rose Bowl pretty substantial. >> Yeah, I mean I mean, this is going to be a one of the biggest telescopes ever. You're pushing not just boundaries of astronomy, but in order to do that, you're They're to be pushing the
21:06boundaries of like engineering, right? >> Absolutely. >> Straight up mechanical engineering and like engineering. >> This is the thing I think people don't This So this telescope is expensive. I'm just going to be honest with you. These are billion-dollar telescopes. Yeah. There's a reason. It's because of that engineering, right? I mean, it really is a one-of-a-kind telescope. You can't just go on Amazon and order one of these telescopes. >> Right. Or even parts. >> No, everything has to be designed, right? And it also has to be in Chile where we have earthquakes, you know, pretty significant earthquakes. So the telescope's designed to withstand a 9.0 earthquake. >> Okay. >> There's all sorts of Yes, they have weather and and you know, it's a 22-story building that has to rotate and point and I mean, it's remarkable that you can do it at all, right?