Neil deGrasse Tyson Explains the James Webb Space Telescope

[Music] star talk uh an explainer explainer we do this sometimes jack hey hey i need you there when we get when we do explainers but this one i know a little bit about we're going to talk about the james webb space telescope i know a little bit about it but not enough to fill a whole explainer on it so we reached in to nasa headquarters and we found we found the chief scientist and there he was and he's on star talk right here right now jim green jim it's a delight to have you we go way back thanks for being on star talk neil my great pleasure and chuck good to see you again definitely good to see you jim jim green you you you you come to us as a planetary scientist from way back and your chief scientist at nasa and you're retiring next year will we go what will we do what are we going to do oh my gosh and wait wait you're retiring right when the james webb space telescope deploys this is a little suspicious if you ask me [Laughter] not not really but after 42 years you know it's uh it's time uh you know to step into retirement but you know i'd like to uh continue to work with nasa i have several papers i need to finish i want to work with nasa on gravity assist and uh you know uh do these things that i like to do so you've got a gravity assist podcast that's the best title ever for a podcast i just want to thank you put in my vote for that and you just published a book a 50-year review of planetary exploration at nasa and it just came out just congratulations on all of the above the podcast the book the retirement the career and now we got to pick your brain about james webb space telescope yeah i got 100 questions and i just want to hear it from the horse's mouth sorry to call you a horse in this but a mouth i do have all right everyone is thinking of this as like the replacement for hubble so could you just amend that thought for us all yeah you know when we go into space we have the wonderful opportunity to look in different wavelengths wavelengths of light that don't make it to the surface of the earth now hubble actually looked at the visible many of those wavelengths all those wavelengths make it to the surface of the earth but not into the infrared and that's why we needed a new telescope and that's what the james webb space telescope does it it really hones in on a brand new wavelength regime that we haven't done much with so uh what intrigues me is when i first learned of the james webb and how it's tuned for the infrared i being fundamentally a a large-scale structure guy of the universe i was very excited to recognize that it will be able to see the formation of galaxies in the early universe in a band of light that is red shifted into its into its zone i mean right it's it's like the universe is as it's like put it here universe and then we got you right right yeah well it's a it's a time machine yeah so basically yeah the further it looks the further those objects are away the further back in time we see them and their light was started out as ultraviolet or maybe even some x-rays and by the time it reaches us through the expanding universe it's landing in our lap as infrared and you got the damn telescope to find that but then to learn that it's not only finding the farthest reaches of the universe infrared can actually peer into gas clouds so tell us about that ah well that's a really important uh aspect of it because it allows us to look at the birth of stars and their associated planets and that really is uh exciting to see and these are just right in front of our noses right so yeah and that's what intrigues me it's the farthest reaches of the universe and things that are happening right in our backyard our cosmic backyard right within our own galaxy where do you decide to point it first ooh good question oh well you know uh uh scientists um uh propose right there's a cage match there's the octagon with the chainsaw don't forget the chainsaws you got to have that seriously you got to put that in but that's got to be your retirement legacy you know the first light on a telescope is whoever wins the cage match among the astronomers you got to do that yeah right indeed well you know much of that early part of the program has been worked out but we also have some time about a hundred hours that have been set aside to look at the solar system now this is really an exciting thing because i was at nasa headquarters as head of planetary science uh from 2006 on and in about 2007 we went through a review on what jwst could do and in that review i said at the end of it well aren't we going to use it to look at objects in the solar system because our sun heats them up and they glow in the infrared and we can look at aurora infrared aurora on planets all kinds of things were coming to my mind and i was told no this is an astronomy telescope and we can't track things and so um ellen stern the aaa at the head at the time turns he's mr pluto he's mr mr please allen pluto stern that's his middle name [Laughter] don't get anything started don't derail this conversation so so alan turned to me and said um well what what do you think we ought to do about it i said let's let's take a second and see if uh what needs to happen for jwst to track objects in the solar system and so it was early enough in the development the project went away and they came back a couple months later and said we got great news it's just a software uh set of mods that we can make and we can track things from mars on out wow wow so there's an important point you're making there because when we see the distant universe nothing is moving at any rate that matters to you just sit on that spot on the sky but everything in the solar system is moving yeah and of course we need time to collect those photons even though we have a huge collecting area we want to see out into the kuiper belt you know and that they'll emit in uh infrared but they're so far away from the sun that it will still be dim because of which pluto is a prominent member yes yes one of the archetype members of uh or you mean escapee i don't know oh dear oh what have i done you know uh some of them haven't escaped you've got triton which is probably a a a kuiper belt object you know in orbit around neptune so so what what happened is the project said it just cost money now's the perfect time to do it add the money and we can complete the software and track uh track objects and alan turned to me and said green you got the money and i said i'm going to do whatever i can to get you the money and indeed that's planetary's investment in this spectacular telescope is is getting the software that enables the telescope to track objects from mars on out in the solar system that's that's a beautiful thing and and uh remind us where this thing is getting planted it's not just in earth orbit like hubble that's right it's in a very special place and uh this particular place is behind the earth in in what we would call the earth's magneto tail okay and it's called uh l2 it's a little it's an anatomical part you know yes that's right a magnetotax it sounds like a new x-man magnetotail so so that's that's how you remember to pronounce magnetosphere correctly is think of magneto and then put a sphere on the end of it good good nice all right so this is on the other side of the moon right no it's directly behind the earth in line from the earth to the sun oh interesting l2 is behind us and and it's a unique place because what's happening is in that location it's really orbiting the sun but because it's behind the earth it would move slower around the sun than the earth does but here's where the earth comes in the gravity for from the earth pulls it along and so not only the sun's gravity but the earth's gravity keeps it in a nice position we call l2 which is like 920 million miles away from the earth so this has nothing to do with the moon moon keeps doing its orbit around the earth right like like nothing's happening while this spacecraft is still out there so if you're an l2 can we get there to service it in case we need to i know that's a big topic a lot of people ask that and the answer is it never was planned to be serviced so uh-huh so i'm going to be able to do that at this stage at this stage okay so in principle though l2 if it's going to be a happening place to plunk future space telescopes and and whatever else might live there because lagrangian points those are those are fun points to hang out in um i can imagine i'm making this up just spitballing here nasa has a has a has a has a handyman mission it's the handyman uh uh uh vehicle that goes out there and you and you collect all the the spacecraft that need um all the space telescopes that need repair and then it comes back how about that well that's a good thought uh but that's not nasa's thought our prime mission is indeed uh for a nominal five-year mission but it has fuel to station keep meaning stay in l2 you know uh for about 10 years wow yeah i'm thinking of a handyman mission okay i'll work on that jim we'll call it nasa's aaa oh you need you got a flat you need you need a jump [Laughter] well you may need fuel that's probably what you'll need i i can't i can't believe i locked myself out of my satellite wait so jim jim i got one last question because we're running short on time is there a mode the telescope can go in that is because what i'd always loved even telling the public about that we do as scientists is of course you design an instrument for what you intend to find all right that's how you know what the parameters are and what the specs should be but is there a mode where it's just looking for nothing like a serendipity mode so in case something shows up that nobody ordered nobody was looking for and we end up scratching our head when it shows up like every other telescope in new york city well like hubble you know which decided okay we've got some spare time let's just stare in an area and then found the you know fabulous array of galaxies that it did there'll probably be some time when we will you know look in a particular area and then just turn it on and see what we find but at the moment it's really well subscribed as we would say you know we have a hundred hours uh uh open to the planetary scientists to make a variety of measurements of solar system objects that data will come in and be available to all the other planetary scientists and and then many of the astronomers uh will have already accepted proposals and they'll be uh you know following following that schedule that they've created but that won't really kick in until six months after launch okay and but the point with that famous photo the hubble deep field we're just stared at nothing for a long time it became one of the most famous images it ever took that was the director of the hubble space telescope institute saying do this and i don't care what anyone says because i'm the director and i have directors discretionary time is there someone in jbj because it's not gonna be you because you're retiring is there somebody's gonna say let's just do this don't judge me until after is there someone who has that power perhaps um you know another cage match [Laughter] but hubble was up for many many years before that all right and therefore therefore they they felt they they had opportunity to then reach outside the normal set of things that they'd be doing to discover something new and important perhaps and so that's why i say initially it's really well subscribed we've got so many things we know we need to uh make those observations to make those discoveries and so that's first on the list all right jim it's been great to have you on here we've got to end it there but we look forward to the launch we look forward to the successful deployment uh that's going to be a nail biter uh deploying something that's never existed before who knows if somebody forgot to you know unlatch something before it was loaded right you know that's then someone needs some explaining to do on that uh but anyhow we look forward to this and congratulations on a a marvelous career uh i've known you ever since i've known nasa so i feel like uh you and nasa have become one yeah thank you that was very kind of you to say and your gravity says podcast check it out and of course of 50 years of planetary exploration just published by nasa and so you can uh check that out as well if you want to sort of eavesdrop on on what was going on so a chuck always good to have you man always a pleasure excellent neil degrasse tyson here as always keep looking up [Music]

Channel: StarTalk

Views: 1,117,336

Keywords: startalk, star talk, startalk radio, neil degrasse tyson, neil tyson, science, space, astrophysics, astronomy, podcast, space podcast, science podcast, astronomy podcast, niel degrasse tyson, physics, jim greene, james webb space telescope

Id: ULxl7pfeUL4

Length: 15min 22sec (922 seconds)

Published: Tue Dec 21 2021