How Webb Illuminates Stars’ Cloudy Origins

01You're listening to NASA's Curious Universe.

02I'm your host, Jacob Pinter.

03Out in the cosmos, in the space between stars, gas, dust, and ice mingle in dark clouds.

04Eventually, after millions of years, these clouds will evolve into stars with planets orbiting them.

05With telescopes, we can see how it all happens.

06And in a lab in the Netherlands, you can almost put your hands on it.

07I always like to say that, you know, this is one cubic centimeter of interstellar space or something like that that we have in the lab.

08Evina van Dyshoek is an astronomer based at the University of Leiden in the Netherlands.

09To figure out how those dark clouds become stars, she combines telescope data with what she sees in the laboratory.

10Your experiments in the lab on Earth will take hours, which is good because then a student can finish it in a day.

11Whereas in space, they would take hundreds of thousands of years.

12On Earth, you can't manage a perfect simulation of space.

13But in some ways, you can get close.

14Those clouds of dust and gas are far colder than anything that happens naturally on Earth.

15They can be below minus 400 degrees Fahrenheit, not far from absolute zero.

16Reaching those temperatures is actually not the hard part.

17We can't achieve the emptiness of space.

18And even the best ultra-high vacuum that we can make in a laboratory on Earth is still a million times more dense than what we have in space.

19So when an astronomer talks about a dense, dark cloud, it's still much more empty than anything we have in a laboratory here on Earth.

20In the lab, you get a close-up view of the same chemicals we find out in space.

21And that helps us understand how they behave and how we can detect them.

22Scientists study these clouds and their chemistry in a number of ways.

23And they have a groundbreaking new tool.

24NASA's James Webb Space Telescope.

25In space a million miles from Earth, Webb is giving us views of the cosmos that no other telescope can.

26And that includes the clouds where stars form.

27Now, Evina is a distinguished astronomer who has won a number of major awards.

28But at the beginning of her career, she didn't set out to study space.

29As a high school student, Evina decided she wanted to be a chemist.

30At university, she realized she was interested in physics, too.

31And then there was one other influence.

32And then my boyfriend's now husband was actually studying astronomy.

33And he realized that there were also molecules in space, that there was chemistry in space.

34And so at some stage, he actually said to me, well, isn't that something for you?

35And so that is how I actually made the transition from pure chemistry, studying theoretical chemistry, quantum chemistry, to astronomy.

36I mean, that's a good boyfriend who points you in the right direction, I guess.

37Well, I've never regretted that transition because the space between the stars is such a fantastic chemical laboratory also that it's much more exciting than a laboratory here on Earth.

38Scientists are studying those chemicals to understand not only how planets form, but how they end up with water and even the building blocks of life.

39And by exploring this process in space, we can also learn more about why Earth has water and life.

40For decades, Evina has been part of an international collaboration to make that research possible.

41NASA and ESA, the European Space Agency, built an instrument on the James Webb Space Telescope called MIRI.

42MIRI is an acronym that stands for Mid-Infrared Instrument.

43One of the things that's so special about Webb is that it sees in infrared, a part of the light spectrum human eyes can't see.

44If you've ever seen a movie character use night vision goggles that detect heat signatures, even in the dark, well, Webb is doing something similar to that.

45Looking at infrared light allows scientists to peer inside dark clouds and see details that otherwise stay hidden.

46Of the four instruments on the Webb, three of them focus on a portion called the near-infrared.

47MIRI gives a different view, like a painter unlocking a new set of colors.

48It collects images and also spectra, scientific data that provide detailed information about molecules in space.

49But MIRI also presents a unique challenge.

50Webb has to stay cold.

51Otherwise, heat from the sun and Earth would interfere with its night vision goggle view.

52So Webb has a huge sun shield that blocks the sun's radiation, keeping the telescope extra cold.

53MIRI needs to stay even colder than the rest of the telescope.

54So, on board Webb, MIRI has its own special refrigerator called the cryo-cooler, which uses helium to maintain a temperature below minus 440 degrees Fahrenheit, hovering just a few degrees above absolute zero.

55And Webb doesn't do this research alone.

56Scientists like Avena can use Webb to tag-team with other telescopes, including a powerful one in Chile called ALMA, the Atacama Large Millimeter Array.

57I was excited to ask Avena about Webb and how she helped bring part of the telescope to life.

58When did you first start working on the James Webb Space Telescope?

59I wonder if you can take me back right to the beginning.

60Right.

61So, that must have been sort of the late 1990s.

62We were just coming out of the Infrared Space Observatory, the ISO satellite.

63It was an ESA satellite that for the first time had measured infrared spectra above the Earth's atmosphere.

64And we had realized how incredibly rich these spectra were.

65And at that time, the mid-infrared instrument was still sort of TBD.

66It was still not sure that it was going to be on Webb.

67And so, it was that late 1990s, early 2000s, when as a small group, we started to make the case and said, you know, Webb really has to have also a mid-infrared instrument.

68And fortunately, we were successful in making that case.

69And it became not just a simple imager, but also with a proper spectrometer on it that we argued very hard for, based on the data that we had gotten from that earlier satellite.

70And that's what we now have.

71And so, the first public data came six or seven months, I think, after the telescope launched?

72Those were some agonizing months still where, you know, the telescope had unfolded and it was getting sharp.

73But Miri still had to be cold.

74And so, that was always one of those moments, you know, will the refrigerator turn on?

75Will the cooler turn on to make the instrument cold?

76So, that was, for me, an enormous relief when we could see on the live webcam, the temperature actually of Miri going down and down and down until finally it was at the temperature where it could actually operate.

77What a whirlwind.

78Yeah, yeah, yeah, yeah.

79But it had a happy ending.

80And once you did get that data for the first time, and then you got more data, and you got the chance to work through it, what did you actually see at first?

81And I guess, can you compare the details you saw from James Webb to data that you had had before James Webb launched?

82Yeah, that's a very good question.

83Of course, in the beginning, you try to also look at something that you've seen before.

84One of that was images.

85So, one thing that JWST, of course, excels at is the imaging.

86And the really fantastic and beautiful in-depth imaging that is now possible with Webb.

87So much detail that you see there.

88But my scientific heart is mostly in the spectra.

89And when we first got some of those spectra, you know, it was just a much richer, a much higher quality than we had been anticipating.

90And so I remember seeing some of it and saying, wow, if I compare that with, in particular, either the Infrared Space Observatory from the 1990s or the Spitzer Space Telescope, which also has been a fantastic trailblazer for Webb, then we could see just the enormous improvement in quality of the spectra.

91What used to be just tiny little wiggles in the older data now were sort of booming lines that we could very clearly see and identify.

92So that was just one of these moments that you dream of.

93So let's talk a little bit more about what we know about the science and what we're learning.

94I'm imagining a planetary system kind of like a cake.

95Like by the time you get to our solar system and you have all these beautiful planets, it's, you know, it's done and the frosting's on it and it's ready to eat.

96But if you're going to make a cake, you need a recipe.

97And before you start the recipe, you have to gather your ingredients.

98So I'm wondering if we are going to make a star or a planetary system, what are the ingredients that we need or that we might see at the beginning that will turn into that system?

99Right.

100So indeed, that's an analogy that I very much like, that there's a lot of excellent research being done on exoplanets, but they have already come out of the oven and we are actually providing the ingredients that go into making that cake.

101So actually, those ingredients start already at the very early stage when the dark cloud in which a star forms is actually collapsing under its own weight.

102And those clouds are cold.

103And that means that atoms and molecules that are in the gas can actually freeze out, collide with the cold dust grains and form an icy layer.

104Think a little bit about it when you have your car on a cold winter day and you know that, you know, an icy layer can form on it simply from the atmosphere, molecules freezing out onto your windshield.

105So the same thing happens there with these dust grains.

106Atoms, molecules freeze out, but then also new reactions can actually occur on those tiny little dust grains.

107They are sort of a place where atoms and molecules meet and greet and can actually form new compounds like water, for example.

108Most of the water that we see and that we have here on planetary systems was actually formed on those tiny little dust grains in the cloud, out of which the star and its planetary system collapsed.

109Okay, so that is something that Webb can now study with exquisite detail.

110It sees not just the water eyes and the carbon dioxide eyes, but it sees also molecules, much more complex molecules.

111For example, methanol, even ethanol, simple alcohols, simple sugars, molecules that, you know, could be important in not just bringing water, but also bringing organic material to the services of new planets.

112So a lot of the chemistry is sort of a lot of those ingredients, actually, that you need to make your cake are already inherited from that very early stage.

113And so if those are our ingredients, what does the recipe look like then?

114Like how does all of that come together and get smushed into something and come out the other side as a star and maybe a planet or some planets orbiting it?

115Well, that is a very good question.

116The star basically originates from the collapse of the cloud and then the process of its heating up over time.

117That's basically gravity doing its work.

118Exactly how a planetary system is formed, that is still one of the big questions in astrophysics.

119And what we do know is that these tiny little dust grains, just a small fraction of the width of your hair, that they can actually collide and grow to larger bodies, say pebbles, say rocks, say planetesimals, as we call them, comet-sized bodies, about a kilometer in size.

120Those pebbles and those planetesimals, those are actually the building blocks of new planets.

121I remember way back in elementary school or something, you know, we learned that the Earth is 4.6 billion years old and that before it became a planet, it was this disk of spinning, I don't even know what, dust and gas maybe?

122Is that something that you see out there in the cosmos as well?

123Oh yes, indeed.

124It was in the 1990s that actually these disks were actually seen, convincingly seen for the first time.

125And then ALMA, the Atacama Large Millimeter Array, has now beautifully imaged these rotating disks of gas and dust around many young stars.

126So we now know that they have the size of typically our solar system and that they are also not smooth.

127They contain gaps, cavities, structures, bumps in which the dust grains actually collect.

128We call them dust traps.

129And so that all now plays a role in what we are now seeing with JWST.

130And what we see there is just an incredible richness of molecules.

131Some of them are very rich in water.

132Others are rich in CO2.

133And then the big surprise is that we have found some disks that are actually very rich in carbon-containing molecules.

134They have very little water, but they are booming in, for example, acetylene and some of them even in benzene.

135So there's a lot of sort of chemistry and cooking still going on in that inner part of the disks around the young stars that we do not fully understand yet.

136But that may have a large influence on what kind of planets we actually make there.

137I mean, one of the big, maybe the biggest questions that NASA and other space organizations want to know is, could there be life out there?

138Could we somehow detect signs of life?

139And we're looking for it in all kinds of different ways.

140But when I hear you talk about the ingredients for stars and planetary systems and finding water in lots of places and finding some organic chemistry or precursors to organic chemistry, that's where my mind goes right away.

141Is that something you think about?

142Is it something you look for?

143And I guess, how do you think your research fits into that?

144Yeah, it's, of course, the ultimate question and the question that certainly fascinates humanity.

145I always like to get to the point of providing, you know, the biologist with the ingredients.

146Water, water is clearly there.

147It's a lot of that.

148There's plenty of water around most forming stars and in most disks around these young stars where planet formation occurs.

149So there is quite a lot of water.

150Not all of them may make it to the terrestrial planet forming region, but certainly in the disk as a whole, there is a lot of water.

151There's certainly a lot of organic material.

152So those ingredients are available.

153What the steps are that then will ultimately produce life is something that I, you know, very much like to leave to my organic chemistry and biology colleagues.

154There's a lot of work going on now in trying to understand how to make the first cell, for example.

155We know we have all the basic building blocks, but how to then actually put a puzzle together, how to put sort of the Lego pieces together to get there.

156That is something that certainly I don't have enough expertise in.

157I'm probably a little bit more conservative than some of my other colleagues in terms of when we will find the signatures of life.

158That is still going to take some time and instruments and missions beyond JWST.

159But all the steps that we are making now in terms of knowing what the ingredients are, where and how everything is coming together.

160That are just all key steps in this whole sort of story towards finding life elsewhere in the universe.

161Well, I've got one final question for you.

162The name of our show is Curious Universe.

163So I always like to ask, what are you still curious about?

164Well, I should say as a chemist, I'm really curious as to how those atoms come together to form, you know, even the simplest molecules.

165We have theories for that, but at some stage you would really like to see it with your own eyes.

166I think actually just knowing what made our Earth and whether or not it is special, I think that would also be an incredibly important question, putting our own Earth into context.

167I'm still from the Star Trek generation.

168So sometimes I wish that I could just be a science officer on a starship and just travel to the Orion Nebula and really take a scoop of the material there and just study it in great detail and then see what is everything that is really there.

169Evina van Dishoek is an astronomer based at the University of Leiden in the Netherlands.

170You know, some of Webb's most striking images feature nebulae where stars are born.

171We're going to include one of those images in the web page for this episode.

172It's a section of the Lobster Nebula, which is several thousand light years away from Earth.

173In this image, you see young stars that are extremely hot, some of them eight times hotter than the Sun.

174And these infant stars have shaped jagged peaks in the nebula's cloud and carved out a cavity in the gas.

175I mean, you can really see how punishing the winds and radiation are that come from stars being born.

176You can find that web page and transcripts for every episode of this show at nasa.gov slash curiousuniverse.

177For more information and the latest news about the James Webb Space Telescope, head to nasa.gov slash web.

178And if you liked this story, you will love NASA's documentary Cosmic Dawn.

179To deliver the science data you heard about in this episode, Webb's engineers spent decades designing the telescope, building and testing it, and finally launching it a million miles into space.

180We had this singular purpose for 25 years to make the James Webb Space Telescope a reality.

181And, you know, people did think we were nuts at first because the technical challenges were so daunting.

182And the number of things we had to advance or literally invent were numerous.

183Pop some popcorn and experience the incredible true story of the James Webb Space Telescope in the NASA documentary Cosmic Dawn.

184Head to nasa.gov slash cosmicdawn.

185This is NASA's Curious Universe.

186This episode was written and produced by me, Jacob Pinter.

187Our executive producer is Katie Conans.

188The Curious Universe team also includes Christian Elliott and, of course, Patty Boyd.

189Christopher Kim designed our show art.

190Our theme song was composed by Matt Russo and Andrew Santaguida of System Sounds.

191We had fact-checking help on this episode and others in our web series from Laura Betts, Elise Fisher, Amber Strawn, and Stephanie Milam.

192As always, if you enjoyed this episode of NASA's Curious Universe, we would love to hear about it.

193Leave us a review wherever you're listening right now.

194Maybe send the link to this show to one of your friends.

195And remember, you can follow NASA's Curious Universe in your favorite podcast app to get a notification each time we post a new episode.

196Three, two, one.

197This is an official NASA podcast.

198NASA podcast.