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A cosmic chronicle
Are you ready for the greatest story ever told? Launched in France on 25 April 2024, Space Odyssey is the first complete history of space in graphic novel form. Drawing on the latest scientific and historical sources, it tells the story of the men and women who pioneered humankind's journey into space.
The spacecraft control centre of the future
Oldest known human viruses found hidden within Neanderthal bones
Oldest known human viruses found hidden within Neanderthal bones
Perseverance Wraps Up Over 1,000 Days on Mars. Still Going Strong
I can remember when Perseverance was launched, travelled out into the Solar System and landed on Mars in February 2021. In all the time since it arrived, having clocked up 1000 days of exploration, it has collected 23 samples from different geological areas within the Jezero Crater. The area was once home to an ancient lake and if there is anywhere on Mars to find evidence of ancient (fossilised) life, it is here.
The date was 30 July 2020 when a gigantic Atlas V-541 rocket roared off the launchpad from Cape Canaveral in Florida. On board was the Perseverance rover, on its way to Mars. It arrived around 7 months later, entered the Martian atmosphere and successfully landed using a complex sequence of parachutes, retrorockets and for the first time, a sky crane to lower it from a hovering platform. Its chief purpose on Mars was to explore the geology, climate and atmospheric conditions as a precursor to human exploration.
A United Launch Alliance Atlas V rocket with NASA’s Mars 2020 Perseverance rover onboard launches from Space Launch Complex 41 at Cape Canaveral Air Force Station, Thursday, July 30, 2020, from NASA’s Kennedy Space Center in Florida. The Perseverance rover is part of NASA’s Mars Exploration Program, a long-term effort of robotic exploration of the Red Planet. Photo Credit: (NASA/Joel Kowsky)The landing site, the Jezero Crater, was chosen because previous orbital studies revealed clear evidence of an ancient lake that once filled the crater. It is thought that water is a key ingredient to the evolution of life so if there had been a body of water, then there is a greater chance of life evolving. Studying the rocks here is like taking a flick through the history books as it preserves signs of ancient life and also ancient environmental conditions.
The crater had been formed, like the majority of other craters in the Solar System from some form of impact event. In the case of Jezero it was an asteroid impact around 4 billion years ago. On its arrival at the crater the floor was soon discovered to be made of igneous rock, formed from a huge underground chamber of magma and bought to the surface through volcanic activity. Since then, other types of rock from sand and mud were found providing evidence of the presence of water in Mars’ distant past.
Jezero Crater on Mars. Credit: NASA/JPL-Caltech/ASUBy the time Perseverance had hit the 1000 day anniversary of its exploration of the red planet it had collected the rock samples, safely packaged them up ready for collection and by and large, completed its exploration of the ancient lake bed. One sample in particular which has been called ‘Lefroy Bay’ has been found to contain fine grained silica. This material is commonly found on Earth and known to preserve fossils. Another of the samples contains phosphate which, on Earth is most definitely associated with biological processes. Both of these contain carbon which can be used to study the environmental conditions from when the rock formed.
Jezero crater is a big place, 45 kilometres across so deciding on where to collect the samples was challenging. When a target site had been identified, Perseverance would first use its abrasion tool to wear away the surface and then use the onboard instruments such as PIXL, the Planetary Instrument for X-ray Lithochemistry. The instruments on board have the ability to detect both microscopic, fossil-like structures and also to identify chemical changes left behind by ancient microbes. Alas to date, whilst Perseverance has achieved an amazing amount, the detection of signs of life have alluded the rover.
Source : NASA’s Perseverance Rover Deciphers Ancient History of Martian Lake
The post Perseverance Wraps Up Over 1,000 Days on Mars. Still Going Strong appeared first on Universe Today.
Astronomers Try to Directly Observe Epsilon Eridani b. No Luck. Maybe Webb Can Find it?
Back in the year 2000, Epsilon Eridani b was discovered. It is a Jupiter-like exoplanet 10.5 light years away but it has taken decades of observations to learn more about the planet. One thing that remains a mystery is it’s orbit which, until recently has been unknown. There has never been a direct image of the planet either, so now, it’s the turn of JWST to see what it can do.
The concept of exoplanets has been around for a few decades now but the first confirmed discovery occurred in 1992. Astronomers at the Arecibo Observatory discovered a number of Earth-mass planets orbiting around the pulsar PSR B1257+12. Since then, over 5,000 planets have been discovered around other star systems. Astronomers use a number of Studying them once they have been confirmed requires more direct study.
The Arecibo Radio Telescope Credit: UCFOne such exoplanet is known as Epsilon Eridani b which also goes by the name AEgir. Exoplanets are named after their host star (in this case Epsilon Eridani) and the letter ‘b’ designates that it was the first exoplanet discovered around that star. The next to be discovered would be ‘c’ and so on although in the case of Epsilon Eridani it is the only planet. It is thought to orbit around the star at a distance of 3.5 astronomical units (where 1 AU is the average distance between the Sun and Earth) and takes about 7.6 years to complete one orbit.
One area of exoplanet study that has been lacking over recent years is the study of the surface and atmospheric conditions, in particular a study into their potential habitability. Cold exoplanets seem to have received the least study due to their faint appearance in the mid-infrared wavelength. Due to the properties of these cold planets, direct imaging techniques are required and must employ high contrast processes. To date, no instrument has been capable of delivering.
The crux of the challenge is that the cold exoplanets have no intrinsic energy source and only re-use the radiation from the host star. Their luminosity is based upon their size and distance from host star but usually the radiation is at the same wavelength as the emission from the star. To address this challenge, a paper has been published in ‘Astronomy & Astrophysics’ journal by a team led by C. Tschudi from the Institute for Particle Physics and Astrophysics in Switzerland.
The paper provides an insight into high contrast observations of Epsilon Eridani taken in 20198 and 2020 using the VLT (Very Large Telescope). Using the SPHERE instrument (Spectro-Polarimetric High-contrast Exoplanet Research) as part of the ongoing RefPlanets programme, the team were able to use polarising technology to search for signals from the planet.
In mid-August 2010 ESO Photo Ambassador Yuri Beletsky snapped this amazing photo at ESO’s Paranal Observatory. A group of astronomers were observing the centre of the Milky Way using the laser guide star facility at Yepun, one of the four Unit Telescopes of the Very Large Telescope (VLT). Yepun’s laser beam crosses the majestic southern sky and creates an artificial star at an altitude of 90 km high in the Earth’s mesosphere. The Laser Guide Star (LGS) is part of the VLT’s adaptive optics system and is used as a reference to correct the blurring effect of the atmosphere on images. The colour of the laser is precisely tuned to energise a layer of sodium atoms found in one of the upper layers of the atmosphere — one can recognise the familiar colour of sodium street lamps in the colour of the laser. This layer of sodium atoms is thought to be a leftover from meteorites entering the Earth’s atmosphere. When excited by the light from the laser, the atoms start glowing, forming a small bright spot that can be used as an artificial reference star for the adaptive optics. Using this technique, astronomers can obtain sharper observations. For example, when looking towards the centre of our Milky Way, researchers can better monitor the galactic core, where a central supermassive black hole, surrounded by closely orbiting stars, is swallowing gas and dust. The photo, which was chosen as Astronomy Picture of the Day for 6 September 2010 and Wikimedia Picture of the Year 2010, was taken with a wide-angle lens and covers about 180 degrees of the sky. This image is available as a mounted image in the ESOshop. #LUnfortunately the team were unable to successfully detect Epsilon Eridani b despite a total exposure time of 38.5 hours spread over 12 nights. This was however, useful at understanding the limitations of the instrumentation. What next then? Well it looks like we have to wait for a next generation of infrared sensitive instruments to peer deeper into the system. The James Webb telescope is a fine example of such a device and, once it turns its sights onto Epsilon Eridani maybe the mysteries will finally be resolved.
Source : SPHERE RefPlanets: Search for ? Eridani b and warm dust
The post Astronomers Try to Directly Observe Epsilon Eridani b. No Luck. Maybe Webb Can Find it? appeared first on Universe Today.
ChatGPT got an upgrade to make it seem more human
ChatGPT got an upgrade to make it seem more human
'Kingdom of the Planet of the Apes' reinvigorates an aging 'Apes' franchise (review)
SpaceX Starship's next launch 'probably 3 to 5 weeks' away, Elon Musk says
Ep. 719 – Galaxy Series: Spirals
Our galaxy series continues, on to spiral galaxies. In fact, you’re living in one right now, but telescopes show us the various shapes and sizes these galaxies come in. Thanks to JWST, we’re learning how these spirals got big, early on in the Universe.
Image: M33 Transcript(Automatically generated)
Fraser Cain [00:01:11] Astronomy Cast episode 719 – The Galaxy series: Spiral Galaxies. Welcome to Astronomy Cast, a weekly fact based journey through the cosmos where we help you understand not only what we know, but how we know what we know. I’m Fraser Cain the publisher of Universe Today. With me, as always, is Doctor Pamela Gay, a senior scientist for the Planetary Science Institute and the director of CosmoQuest. Hey, Pamela, how you doing?
Pamela Gay [00:01:33] I am doing well. When folks are hearing this episode, you’re going to be off in Japan. And that is amazing.
Fraser Cain [00:01:43] Yeah, yeah, we’re making up for that trip. So four years ago in 2020, I booked a trip. Actually, in 2019, I booked a trip to Japan for my son and with my son. And then Covid hit and things got pretty dicey. And so we decided to cancel the trip. And it’s been four years. And now, like, what’s Covid? Who remembers that anymore? So .. so we’re going to do it again. And you know now he’s older and a lot wiser. And I think it’s going to be a really fun time. So yeah yeah. By the time you listen to this we will have been in Japan for a week. And you know, people are like, are you going to do this? Or you can do that. Like, I have no plans. This is purely vacation. I and you know, if I run across Jaxa as I turn a corner in some neighborhood, then sure, I’ll walk in. But I had no plans. I’m not booking things, doing interviews, any of that. I’m going to bring a camera. But … but apart from that, no, this is just purely fun. I want to eat some tasty sushi and noodles. I want to walk around cool parks and temples. I want to ride bullet trains. And I want to meet people there.
Pamela Gay [00:02:53] So yeah, I, I have to say, I haven’t found sushi there that was any better than what I’ve gotten in the US. Other than you can get Fugu there, which you can’t get in the U.S..
Fraser Cain [00:03:05] No, thanks.
Pamela Gay [00:03:06] But the ramen, I had ramen. That is the stuff of dreams. And may you find such.
Fraser Cain [00:03:15] I’m looking forward.
Pamela Gay [00:03:15] To the ramen places.
Fraser Cain [00:03:17] Yeah, yeah, that sounds great.
Our Galaxy series continues on to spirals. In fact, you’re living in one right now. But telescopes show us the various shapes and sizes these galaxies come in. Thanks, Joe is t. We are learning how these spirals got big early on in the universe. All right, Pamela, spiral galaxies. And this is obviously familiar territory because we live in one.
Pamela Gay [00:03:44] We do. Although living in it has made it particularly challenging to study.
Fraser Cain [00:03:49] Right.
Pamela Gay [00:03:50] Like we figured out, there’s a bar in the center of our galaxy only within the past couple of decades. We still see every few years, they change their mind on exactly how far we are from the core of the galaxy.
Fraser Cain [00:04:07] How many arms the Milky Way have, right? Is the last episode we talked about. You know, different controversies are still unfolding. And one of those is how many spiral arms does the Milky Way have? This is a question that is a two. Is it four? Is it two. But then two other kind of arms that are broken off of it. It’s a it is a tricky question because you’re embedded inside like quick. Yes. You know, imagine yourself in a random house. What color is the paint on the outside of your house?
Pamela Gay [00:04:40] It’s a challenge. Is a challenge.
Fraser Cain [00:04:42] Yeah, yeah. Maybe you’ll see it in reflected windows of cars as they drive by.
Pamela Gay [00:04:48] And. And what makes the challenge all the more fun is we have this Andromeda galaxy looming so very close. And at first glance, it seems to be so much bigger than we are. And yet every time we revise our mass estimates, it seems that our galaxy and Andromeda get closer and closer in size. And so it just turns out, trying to understand things that take more than one field of view of a telescope to look at is really hard. Really hard.
Fraser Cain [00:05:21] Yeah, I love those images of what Andromeda would look like if you if it was bright like before and you could see it, it is the size of what is it like nine full moons in the sky? It’s a tick.
Pamela Gay [00:05:34] Yeah. Yeah. And. And then there’s also the challenge of the size of galaxies varies depending on what color of light you’re looking in. And this has been one of the challenges with classifying galaxies, especially spiral galaxies. So the the old school still taught tried and true way of classifying spiral galaxies. Is the Hubble tuning fork diagram. And in this diagram you have ellipticals of varying, roundness to flatness that eventually become what’s called a lenticular galaxy, where you have a nucleus in the center. And then just like a disk of no structure around it, and then it forks. Thus the tuning fork part of the analogy and the arms on on the galaxies for the spirals and the barred spirals just get more and more unwound. But it turns out if you look at galaxies in different colors of light, you’re able to see their arms in different degrees. And so when it comes to trying to figure out how do we write software to classify galaxies, how do we get human beings to classify galaxies? It is a glorious disaster.
Fraser Cain [00:06:59] Right? Right. And I mean, it’s just it’s a mess because galaxies are weird. Yeah. Yeah. It’s not. It’s like humans. It’s the galaxies problem.
Pamela Gay [00:07:10] Go.
Fraser Cain [00:07:10] Galaxies go. Right? Yeah. It keeps keeping weird galaxies. Yeah. So then then how do they form? I mean, we look at these. I mean, there’s some beautiful examples. The whirlpool galaxy, the Pinwheel Galaxy, their nice face on spiral galaxies where we look just right down on to them, as well as ones that are farther away, that are less famous, that are equally as beautiful and indistinct. How do we get this, this, you know, weird shape and some of the structures that we see.
Pamela Gay [00:07:38] So how exactly you go from either blob of mass to spiral galaxy or a whole bunch of dwarf galaxies merging together, which is how these probably formed. But the universe likes to have exceptions to every rule, and I’m just gonna throw that out there. There are always exceptions. Yeah. It looks like we get spiral galaxies through the merger, with the correct angular momentum coming together to set things in a nice, coherent spiral. Then it gets tricky. Tricky, though, because spirals come in different varieties, separate from just how much of their arms splayed out. We have what are called flocculant spiral galaxies, which are spiral galaxies. When you look at them, you see there is what appears to be feathers, flock, flocculant of of spirally bits all throughout them. But there isn’t a clearly defined pair or multitude of arms. It’s just like arm bits all the way down. Then you have galaxies usually that have a companion. We think that it’s the gravitational interactions that drive the, the, spiral density waves that create these grand design spirals, which have two arms, only two arms perfectly formed.
Fraser Cain [00:09:08] And the number shall be two.
Pamela Gay [00:09:09] And the number shall be two, and.
Fraser Cain [00:09:11] Is the arms. Yes.
Pamela Gay [00:09:13] And, and and so going between these extremes is every possible version of massy and glorious. And then we see some spiral galaxies have, rings in their centers, have bars in their centers. And again, this is all driven, we think, from the gravity of companions. And then we have things like the see for 1 in 2 galaxies that have active galactic nuclei that are shooting out jets of radio waves. Spirals are just out there trying to show off. They are the drama queens. They’re the pageant queens.
Fraser Cain [00:09:59] You know, the peacocks galaxy world. Yeah. So this this shape, I mean, it really looks like someone is winding up a bunch of stars from the middle, and you get these spiral arms that form. What? What are the spiral arms?
Pamela Gay [00:10:19] They they are actually just places where material lingers as it goes on its orbit around and around the galaxy. It’s not that galaxies have solid disk rotation where those arms are intact, and the whole thing is bulk rotating like a pinwheel. That is not happening. I just want that very clear. Yeah, yeah. The structure might look like a pinwheel. It is not rotating like a pinwheel. So what’s happening is as material goes around and around the core, there are regions that have higher density. The regions that have higher density accelerate material towards them. So it gets there faster and then holds on to it. So it slows down as it exits. So the amount of time that material stays in the arms is increased compared to the amount of time that it spends on the other parts of its orbit. So you can have material zoom into. I don’t know why I said that like that. You can have material that zooms into a galaxy’s arm, passes through ever so slowly interacting a lot. Star formation gets triggered in arms and then passes out the other side until it gets to the next arm. Rinse and repeat.
Fraser Cain [00:11:41] Yeah. So like analogy that I love to use. Like, imagine you’re in a balloon above the Super Bowl and you’re looking down and the wave is happening. I don’t if do the wave at the Super Bowl. But imagine the wave is happening is you got human beings standing up, shaking their banners, cheering, and then sitting back down again, and you’re seeing this wave propagate through the entire arena. And from your blimp view, it looks like something is turning inside the stadium. But it is not what’s turning. It is the people standing up and sitting back down creating this illusion. And that’s the same thing as what’s happening with the spiral galaxy. Now the whole galaxy can be spinning. That’s a separate thing. But those spiral arms that you’re seeing are these density waves that are just rotating through as all of the stars are doing the wave and they take their time, they have their turn? Yeah. In the in in the arms. And then times when they’re not in the arms.
Pamela Gay [00:12:44] And to be clear, the majority of material in a spiral galaxy, not all. There’s always exceptions. That’s just going to keep coming up. The majority of material in a spiral galaxy will be orbiting all in one direction, like cars on a racetrack should, in theory, all be going in the same direction. And and what we’re seeing is all these things that are going more or less in the same direction are just lingering longer, where there’s a higher amount of mass to pull them in and hold on to them as they try to continue their orbit.
Fraser Cain [00:13:16] But we clearly see these star forming regions in the spiral arms of these galaxies. So what’s that about?
Pamela Gay [00:13:21] So if you think about it, star formation gets triggered through interactions, through shocks, through something taking a nice stable cloud of gas that is supported through the balance of gravity inwards and thermal pressure outwards. It doesn’t take a lot to knock that kind of a cloud out of equilibrium. So as these nice, friendly clouds enter the region of crowding, the probability that something they got there before them is gonna have a supernova go off, the probability that a couple of these clouds are going to interact with each other and knock each other out of equilibrium is a whole lot higher than when that cloud is all by itself in the space between arms. So when these clouds get to the high density region of the arm, they tend to get knocked around. And that knocks them out of that very careful thermo gas dynamics versus gravity balancing act. And you get star formation right.
Fraser Cain [00:14:23] So parts of the cloud are. Hold in, and then you get the densities that can begin and trigger this star formation.
Pamela Gay [00:14:31] Or it could. It could literally just be the shockwave from the supernova hit it to these clouds. And there’s a lot more supernova going off in the arms where you have a lot more star formation, and supernovae go off when you have star formation, and those first giant stars die.
Fraser Cain [00:14:48] Right, right. It’s this cycle that just gets rolling. It’s it’s crazy. Like I just sort of imagine this wave sweeping past. And as the wave is sweeping past through space, you’re getting clouds of stars start to form in this and then supernova are going off in this triggers more star formation. And then the wave passes and the fuel is depleted and you have less stars in that region. But now the next region gets filled with stars. It’s a it’s a very, I don’t know, very evocative concept to think about.
Pamela Gay [00:15:22] A better analogy might be a traffic jam. I don’t know if you’ve ever been like driving along on a road trip, full tilt buggy, and all of the sudden, three miles ahead, there is an accident on the complete other side of the highway. There’s no reason for your side of the highway to slow down. Yeah, but it turns out because human beings are human beings, they will race forward. And end up piling up. And then when they get close to that, that accidents are like must look, must look.
Fraser Cain [00:15:57] Must the what is it? How many.
Pamela Gay [00:15:59] Feet.
Fraser Cain [00:16:00] Yeah.
Pamela Gay [00:16:01] And so you end up with this, this compression wave triggered by looky loos. And that causes a compression of cars in that one place. Well, here it’s the gravitational wave of looking at the car accident that’s causing the compression and the lingering in the galaxy. It’s the gravitational pull of all the cool stuff going on that has mass and is holding you in place.
Fraser Cain [00:16:31] So once again, g t has joined in the hunt for galaxies. And because these things are fairly large and fairly bright, it’s seeing spiral galaxies early on in the universe. Yeah. So give me give me some surprising discoveries about spiral galaxies thanks to J team.
Pamela Gay [00:16:51] So so we thought that they would come very slowly in the being. It would take billion, couple billion years for them to exist, built up through the slow aggregation of smaller systems into larger systems. And it turns out something happened. We we don’t know exactly what happened. J t still looking and hundreds of billions of years, not a billion years, hundreds of millions of years. We’re already starting to see spiral structure. It’s not perfect, at least not what we can see through j w s t which admittedly isn’t that many pixels across, but still, it’s enough that we can see the spiral structure. Wow. And and so it turns out that somehow these things are forming faster and earlier than we thought through means that are still being defined. And there’s so much to figure out. Like if if you look at the velocity curve of a dwarf irregular galaxy, they have the same velocity curve structure as a spiral galaxy. So these dwarf irregulars that look like dead bugs on the sky have stars that are mostly going around and around in one direction in a known way related to dark matter. And then we see spiral galaxies. And so how are these things merging to get us bigger systems? Are they forming just big and spiral? We don’t know. We’re figuring it out. It’s a really cool time to realize everything we knew was wrong. And we get to start over and try. Right?
Fraser Cain [00:18:28] Right. And the other thing that this is fairly recent news, I don’t know if you have been following the story, but they’ve found that the galaxies have bars as well early on.
Pamela Gay [00:18:39] And that implies companions.
Fraser Cain [00:18:41] Right? Right. Which was what you were talking about earlier, that there’s some kind of interaction between the galaxy and its companions, leading to this bar forming in the middle. What is this bar?
Pamela Gay [00:18:53] There are so many different papers that don’t say the same thing. So what it is. For reasons that have many explanations, and I am not going to make a personal opinion right now because someone will send me a nasty letter, right? There are galaxies, including our own, that have a companion and have a structure in the center that is linear and radiating out from the black hole, and then these spiral structures appear to spiral off of the ends of this bar.
Fraser Cain [00:19:26] Right.
Pamela Gay [00:19:27] That companion is the consistent part, exactly how the barred structure forms. There’s lots of theories. I’m just going to leave it there and write. Deal with the letters in my inbox.
Fraser Cain [00:19:41] Yeah. So it’s a couple of things. One is that, you know, about two thirds of galaxies have bars, and they appear to come and go over time.
Pamela Gay [00:19:50] Yes.
Fraser Cain [00:19:51] Yeah.
Pamela Gay [00:19:52] So it’s a transient phase, which is consistent with the companion galaxies coming and going, changing in distance, getting consumed actively.
Fraser Cain [00:20:01] Yeah, yeah. And so you can get some event that causes the bar to buckle to, to collapse in on itself and disappear again. And then other times the bar will start to spread out and stretch out, and the arms end up at the end of the, of the bar. So it’s a weird thing. Spirals have them. Yeah. And and yet, as you know, I mentioned this, that the now there’s observations that they’re seeing these spiral bars in galaxies that are under a billion years old, like, you should not have seen these mature structures in galaxies. And yet there they are. So once again, the universe is speed running, its large scale structures, its more mature structures. And this is a surprise.
Pamela Gay [00:20:55] And what I’m really loving is we already knew quasars, active galaxies were much more common in the early universe. We haven’t been able to really make out consistently the structure around them. I studies that you slowed in digital Sky survey to do extremely statistically rigorous looks. Found that there were the same fraction of mergers among quasars as non quasars. So there’s just something special in the systems with quasars that causes them. But there’s something of the early universe. There was more gas than there was more material than. And and so we have all of these weird things that were high energy events creating amazing forces. There was more stuff around to do the mergers that hadn’t formed large galaxies yet. It was basically the pottery waiting to be formed.
Fraser Cain [00:21:51] Right. We talked a lot about dark matter in the last episode, and I think we should definitely talk about dark matter as it relates to a spiral galaxy as well. To what role does dark matter play in the behavior of the galaxy?
Pamela Gay [00:22:06] It changes how they rotate or it changes. I guess a better way to put it, how the stars at a variety of different distances orbit around the galaxy. This was one of the things discovered by Vera Rubin. And what’s was remarkable here is Vera Rubin was trying very hard to do non-confrontational research. Right. She moved away from other topics because she was like, nope, don’t want to deal with the the politics just when you do science. Yeah. And she quite accidentally discovered that as you move out from the core of a galaxy and you get more and more material inside your orbit, it was expected that things would be, going at lower and lower orbital velocities.
Fraser Cain [00:22:54] Like the solar system.
Pamela Gay [00:22:56] Like the solar system. Right. And instead what happens is it just flattens off. This flattens off. Right? So the outer parts of galaxies out to the greatest distances we can see beyond a certain point, everything just keeps rotating at the same rate. Right. And this is because the distribution of dark matter is such that it’s counterbalancing what we see with the baryonic luminous matter and changing the rotation curves. And so we’re essentially trying to map out the distribution of material we can’t otherwise see by looking at the rates at which stars, globular clusters, clouds of neutral gas are going round and around our Milky Way. And poor Vera Rubin, who was trying to do non-confrontational research, discovered this, ended up having to spend about a decade proving that she was right. Along the way, she demonstrated that work done in the 30s by, Fritz Zwicky on, galaxy clusters was the exact same effect. And then the poor woman never got the Nobel Prize for everything that she went through. She got many awards, but it is generally seen as a great oversight that she didn’t get the Nobel Prize for what she did.
Fraser Cain [00:24:11] And I want to I want to sort of just reiterate this, this discovery because I think it it is it is so foundational.
Pamela Gay [00:24:18] And yeah.
Fraser Cain [00:24:19] You can’t hear this and roll your eyes at dark matter, right? Which is what I see a lot of in the comments. And so if you’re like, you know, astronomers just make up this thing called dark matter to blah, blah, blah. You know what? No, no, no absolutely not. That is incorrect. And let me let me sort of give you this insight, right. You measure like here in the solar system, the Earth is going at 30km per second around the sun. Neptune is going five kilometers per second around the sun. There is this drop off in the velocities of the planets as you get farther from the sun. It is this steady line going downward that measures the velocities. You look at a galaxy. Yeah, close to the center of the galaxy. The the rotation rate is increasing. And then you hit this point where you then as you measure outward, it’s like, what is it, 250km per second and little farther away. It’s hundred and 50km per second, a little farther away, you know, still 50. It’s still the same. Or the two one. I forget the exact numbers 220 or 250, whatever. And it just it remains the same all the way out to the outskirts of the galaxy. And so the galaxy is not a little solar system. It is something else. Yeah. And you cannot you just can’t get that rotation curve without ten times the mass in the galaxy that if that if there was, you know, you could see. Ten times the mass in black holes all around the galaxy, and they were visible somehow. Then that would explain it.
Pamela Gay [00:25:51] Yeah, it’s it’s the equivalent amount of matter of taking one Acme brick per solar system sized volume in the outer galaxy. So you can imagine just all these Acme bricks floating around. And the Matcha project has gone looking for the the universal version, which is neutron stars, stellar mass black holes, white dwarfs and hasn’t found them.
Fraser Cain [00:26:17] Yeah. And so you can take a person who like doesn’t who rolls their eyes at this and you say, okay, fine. So how how does this work? How do you get the the stars not slowing down in their orbital velocity like you would see in a solar system? Right. And then the person has to say, oh, I don’t know. Right. Done. You you now are part of the dark matter belief system, right? You like weird observation. Why is this happening? I don’t know, good enough. Join the club. Here’s your membership card. You’re now one of us. And so, yeah, it’s called dark matter. But. But who knows what it could be. As you said, particles. It could be black holes. And it could be that we don’t understand gravity at the longest scale. Doesn’t matter. It’s still dark matter.
Pamela Gay [00:27:06] And it can be a combination. I just want to make that clear.
Fraser Cain [00:27:10] It is almost certainly a combination of all of them. And and done. You are like you are part of the confusion that nobody knows what this thing is. And yet you can people can make these observations with relatively small telescopes. If your Rubin did it in the, you know, almost a hundred years ago. And yet here we are still arguing about what it is.
Pamela Gay [00:27:37] And little tiny radio telescopes that universities have allow us to go even further out in the galaxy than what your Rubin initially did with optical light, because we can start seeing the neutral gas that is the furthest stuff out in our galaxy. And so, yeah, grab yourself a small optical telescope and a small radio telescope and you’re done. You can prove there has to be something invisible out there. You’re affecting the rotation curve.
Fraser Cain [00:28:06] And there’s one last piece of spiral galaxy that I think is really important, which is the monster at the heart of them.
Pamela Gay [00:28:13] And and as recently as the 1990s, people were drying on overhead sheets, little tiny monsters, usually with antennae and giant mouths like vomiting jets out of the cause of spiral galaxies. So much has been lost now that professors aren’t hand drawing on overhead sheets. I it’s truly a lost art, and we are suffering so many fewer cartoons as a result of it. Right. So yeah, spiral galaxies. There is a relationship. And this works for ellipticals as well. There’s a relationship between the size of the bulge and the size of the, supermassive black hole in the center. There are some galaxies, like less than ten last I looked, that looked like quite maybe. Possibly it could be they don’t actually have a supermassive black hole and they don’t have a bulge, but still working on it. Yeah.
Fraser Cain [00:29:18] Millions do. Ten don’t.
Pamela Gay [00:29:21] Right. Exactly. Yeah. And and so when you see these systems with large bulges in the core with lots of high velocity stars in those bulges, they’re going to have the big supermassive black holes, smaller bulge, lower motions, smaller supermassive black hole. And yeah. And what’s neat is, depending on the angle that we’re able to look in on a supermassive black hole that’s feeding, we get all sorts of different cool effects. So if you have a system that’s that’s edge on and has a supermassive black hole in the center, it’s called a siefert two. They’re kind of boring. They don’t have very exciting lines that do very much, but they are active and they show up in the radio in new and interesting ways. Now tilt that towards us and you start to get what’s called a Seyfert one, tilt it straight towards us and give it a really powerful jet. And you start to get what’s called a blazer. And here, because of the the distance that it that the time that it takes light from the far jet to get to us and the time that it takes for light from the near jet to get to us, it gives the perspective of faster than light motion between the two ends of the jet. So there’s this really cool physics.
Fraser Cain [00:30:40] Yeah, that’s really awesome. All right, well, I think we can cover two spiral galaxies. And so next week, we pick up the story with the giant elliptical galaxies. Thanks, Pamela.
Pamela Gay [00:30:54] Thank you, Fraser, and thank you to all the folks out there that support us through Patreon. We we really rely on you so very much. Beth, pulled together pretty. In these three episodes for us on a dime. When? When I told her yesterday. Surprise. Yeah, I guess what. And and Rich is out there doing all of the editing, hiding so many blunders. We thank you, Rich. Ali’s out there helping with our YouTube channel. It takes a team to make this happen. This week, I want to thank Kimberly Kimberly Wright. Jesus. Trina, Jeff Wilson, Tim Gerrish, Greg wilde, John Drake, Robert Cordova, Paul de Disney, Veronica cure, Michelle Cullin, Philip Walker, Benjamin Davies, Dwight. Ilke, Brian. Kilby. Daniel. Loosely, Sabra. Lark, Sydney. Walker, David. Borghetti, evil. Melky, Justin. Ace, Maxime. Leavitt, Hal McKinney. Bebop. Apocalypse. I love that one. Daniel Phillips on Bruno. Let’s Ruben McCarthy, Larry Dart’s Bob, Zach, ski time Lord, I row Frank Stewart and Jason could Dorcas folks who donated $10. We are grateful and this means I mispronounce your names. I am sorry you won.
Fraser Cain [00:32:18] Thanks everyone, and we’ll see you next week.
Pamela Gay [00:32:20] Goodbye. Astronomy cast is a joint product of the Universe Today and the Planetary Science Institute. Astronomy cast is released under a Creative Commons Attribution license. So love it, share it, and remix it, but please credit it to our hosts, Fraser Cain and Doctor Pamela Gay. You can get more information on today’s show topic on our website. Astronomy. Cars.com. This episode was brought to you. Thanks to our generous patrons on Patreon. If you want to help keep the show going, please consider joining our community at Patreon.com Slash Astronomy Cast. Not only do you help us pay our producers a fair wage, you will also get special access to content right in your inbox and invites to online events. We are so grateful to all of you who have joined our Patreon community already. Anyways, keep looking up. This has been Astronomy Cast.
Aurora over Idaho
Aurora over Idaho
The aurora paints the sky near Malad City, Idaho, red, purple, and green in this May 11, 2024, image. This aurora was sparked by multiple eruptions of solar material—called coronal mass ejections—colliding with Earth’s magnetic field. This interaction with Earth’s magnetic field can spark a geomagnetic storm and send particles from space rocketing down magnetic field lines toward Earth, where they excite molecules in our planet’s upper atmosphere, releasing light and creating auroras.
Image Credit: NASA/Bill Dunford
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Meet NASA Women Behind World’s Largest Flying Laboratory
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)NASA’s DC-8 aircraft – the world’s largest flying science laboratory – began its science missions in 1987 and since then, has flown in service of the science community over places like Antarctica, Greenland, and Thailand. Aircraft like the DC-8 have enabled scientists to ask questions about life on Earth and explore them in a way that only NASA’s Airborne Science program can make happen. After 37 years, the DC-8 will retire to Idaho State University, where it will serve as an educational tool for students.
As the DC-8 approaches its retirement, we highlight five of the women who have made the aircraft and program a success.
Kirsten Boogaard, Nicki Reid, Carrie Worth, Erin Waggoner, and WendyBereda of NASA’s Armstrong Flight Research Center in Edwards, California, are building the legacy of women who are helping pave the way for the next generation.
Kirsten Boogaard, Deputy Project Manager for the DC-8 aircraft, leads and manages project planning, integration and resources for airborne science missions since 2020.NASA/Ken Ulbrich Kirsten Boogaard Deputy Project Manager
Kirsten Boogaard wears many hats for the DC-8 program, including deputy project manager, mission manager, and assistant mission director.
Since 2020, she has served as the deputy project manager on the DC-8 Airborne Science laboratory, leading and managing project planning, integration, and resources. She is one of three women qualified in the mission director role for the flying laboratory.
“I am really proud of what I accomplish at work,” Boogaard said. “And I am most proud of being able to work full-time and support numerous deployments while having a child.”
Nickelle Reid Operations EngineerAs operations engineer, Nicki Reid authorizes the airworthiness for the aircraft by ensuring that the science instruments added onboard sustain the aircraft’s safety. She also serves as the mission director, where she manages communications with the cabin and cockpit crews.
“It takes a lot of practice to get used to hearing all the different conversations and weeding out what’s important, staying focused, and staying on top of all the action that’s happening,” Reid said.
For a science mission project, that focus is essential to maintaining efficient communication between scientists and pilots. Reid has been honing that skill since she started as an intern at NASA Armstrong.
Airborne science missions are not for the faint of heart! Pilot Carrie Worth and Operations Engineer Nicki Reid are all smiles after landing from a successful science flight.Photo courtesy of Carrie Worth Carrie Worth Pilot
Carrie Worth is part of a team uniquely qualified to fly the DC-8. Her journey to her career as a pilot began as a child.
“When I was a little kid, I saw Patty Wagstaff perform aeronautical stunts at the airshow in Oshkosh, Wisconsin,” Carrie Worth, NASA DC-8 pilot, said. “I decided then and there that I wanted to be a pilot.”
Before joining NASA, Worth served 21 years in the U.S. Air Force as a special operations and search and rescue pilot, and then worked as a 747 pilot for United Parcel Service in Anchorage, Alaska. As a woman working in a male-majority industry, Worth is grateful for the supportive work environment at NASA and the DC-8 program.
“I feel incredibly lucky for the support I have and have had from my male peers,” she said. “I have seen a significant improvement in the [aviation] culture, but there’s still work to be done.”
Branch Chief of the Research Aerodynamics and Propulsion Branch, Erin Waggoner is all smiles onboard the DC-8 during an airborne science mission deployment.Photo courtesy of Erin Waggoner Erin Waggoner Research Aerodynamics and Propulsion Branch Chief
In 2011, Erin Wagonner joined the Research Aerodynamics and Propulsion Branch at NASA Armstrong to support sonic boom research. Today, she is the branch chief.
“I’m thankful for all the mentorship I’ve received throughout my career,” Waggoner said. “Everyone from the maintenance crew to the researchers are very welcoming, willing to share their expertise, and mission-focused.”
Waggoner’s experience with the DC-8 program inspired her to recognize the value of a team spirit in a successful project.
“I’ve learned a lot about team dynamics from my time on the DC-8, like how to integrate new members into an existing team,” Waggoner said. “I love being able to encourage young women interested in NASA and aviation, and learning from the women who blazed the trails ahead of me.”
Keeping things running: Wendy Bereda finds a moment to smile with Operations Engineer Nicki Reid on a maintenance day for the DC-8. She has served the DC-8 program for 25 years.Photo courtesy of Wendy Bereda Wendy Bereda Site Supervisor
Wendy Bereda started working on the DC-8 aircraft in 1999, first as a logistics clerk, later as a project support supply tech. She is now the site supervisor for the maintenance contract at NASA Armstrong.
“Through the years, I’ve received different accolades, but the one that meant the most to me was given to me by Headquarters for my administrative excellence in finding parts and keeping the DC-8 flying.”
As a science-driven platform, the DC-8 project is composed of a team driven to provide the best customer service.
“Our team has so much love for the DC-8,” Bereda said. “We live and breathe to make things happen. This is why I’m proud to have been a big part of the DC-8 life at Armstrong.”
Experts like the women above enrich NASA’s legacy of innovation and exploration, and make programs like the DC-8 a success.
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Tech Today: A NASA-Inspired Bike Helmet with Aerodynamics of a Jet
2 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater) Jim Gentes wearing the Jiro Prolight bicycle helmet.Credit: Jiro
Before the U.S. Cycling Federation adopted a requirement for all bike racers to wear helmets in 1986, most people rode without one. The only helmet options at the time drew rider complaints for being too hot and heavy. But, with a bit inspiration from a NASA aircraft wing design used during World War II, more than 20,000 competitive biker racers would soon have a lighter-weight option to protect their heads.
Jim Gentes, an industrial designer, and bicycling enthusiast developing an aerodynamic bike helmet, saw the new rule as an opportunity. He started Giro Sport Design Inc., now based in Irvine, California, to provide bike racers a speed and safety advantage. Then came the Giro Prolight, a lightweight racing helmet that was cool and aerodynamic, drawing upon a NASA-developed aircraft wing technology.
The National Advisory Committee for Aeronautics (NACA), NASA’s predecessor, developed the NACA 6-series airfoil during World War II to reduce drag in fighter aircraft. Raymond Hicks, an aerodynamicist at NASA’s Ames Research Center in California’s Silicon Valley, helped Gentes adapt that wing design to improve airflow over the helmet, reducing drag. Compared with bareheaded racing, wind tunnel tests confirmed that the reduced drag could save one second in a little over half a mile.
To keep it lightweight, the Prolight used expanded polystyrene foam with a removable Lycra cover. Vents in the front and rear of the helmet let air flow through, using the vacuum created by the rear vents to pull air into the helmet. The vent design also smoothed airflow, reducing turbulence and drag.
In 1986, Gentes added a foam model called the Aerohead. The Hammerhead, a Prolight with a thin shell, came next, followed by the newer, streamlined Aerohead. When Gentes’ friend Greg LeMond won the 1989 Tour de France wearing the Aerohead, worldwide acclaim followed.
Giro has changed hands several times since the 1980s and today, the brand continues to offer bike helmets and other sporting equipment and apparel.
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