Listen: https://soundcloud.com/astrophiz/astrophiz-90-sophia-nasr-self-interacting-dark-matter
Read the full transcript below
Update: Sophia now has her doctorate … Congrats Sophia!
Astrophiz 90: Dr Sophia Nasr – Self Interacting Dark Matter and Galaxy Clusters
This episode’s featured guest is Sophia Nasr, who is a fabulous graduate physics student at University of California, Irvine who is working on her PhD in cosmology and astroparticle theory with a focus on researching Self-Interacting Dark Matter. She brilliantly explains all forms of dark matter research and her passion for cosmology, equity, diversity and outreach.
In the sky:
Observation notes for September include Saturn, Jupiter, the Moon and Uranus.
For those who enjoy watching Live Rocket launches on the internet put September 25 at 1357GMT into your calendar to watch a Soyuz rocket at the Baikonur Cosmodrome in Kazakhstan launch to take
the crewed Soyuz MS-15 spacecraft to the International Space Station with members of the next Expedition crew. The capsule will remain at the station for about six months, providing an escape pod for the residents.
For citizen scientists there is a nice opportunity to participate in the Globe at Night dark sky project, which is concerned with light pollution.
For those in the Northern hemisphere you’ll be asked to report on what you can observe in the constellation Cygnus between Sept 20 and 29 and for Southern Hemisphere citizen scientists you be asked to report on what you can observe in the constellation Sagittarius on the same date range.
To contribute to this worthwhile project, Northern observers can go to tinyurl.comFORWARDSLASHdarkskynorth
And Southern observers can go to tinyurl.comFORWARDSLASHdarkskysouth
And they are both all lowercase, all one word.
In the News.
First up it looks like we have an amazing new interstellar visitor, Congratulations to Gennady Borisov, for his discovery of comet C/2019 Q4 (Borisov). The first interstellar comet ever found and a truly skybreaking discovery!
The Minor Planet Center has published the official announcement.
Reports have also just come in today that water has been detected on a distant exoplanet. The reporting on this discovery is all over the Internet and all over the place in terms of accuracy. No, it’s not an earth-like planet. It doesn’t have water ‘on’ it because it’s most likely a Neptune-like planet with no actual surface, and you wouldn’t survive long enough if you were there to develop any habits. it’s becoming clearer and clearer that terms like ‘habitable’ and ‘goldilocks zone’ aren’t really effective tools for accurately communicating science to the public audiences. If you want to get the lowdown on habitability and exoplanets, you couldn’t do better than to follow Prof Jonti Horner and Dr Elizabeth Tasker on Twitter, or hear from them directly by checking out their episodes at AstrophizDOTcom
It was also sad to hear that ISROs moon landing has run into problems but our fingers are crossed for them and other news from the moon is that the Chinese Rover has detected some strange gel-like substance in a crater.
Next from the Xinhua news agency in China a discovery that may help unravel the long standing mystery of FRBs
Chinese astronomers have detected over 100 repeated fast radio bursts (FRB) – These particular FRBs are mysterious signals believed to be from a source about 3 billion light years from Earth.
FULL TRANSCRIPT;
Episode 90 – Self-Interacting Dark Matter with Sophia Nasr
[Audio Intro] I came out with sets of numbers and I plotted them on pieces of paper.
Radio waves, radio waves, she sees radio waves … Arrays and dishes give different views.
Are you confused? Radiowaves , radio waaaaves.
Brendan O’Brien: Welcome to the Astrophiz Podcast. My name is Brendan O’Brien. Today is Thursday, the 12th of September 2019. And we’re going to start each episode with a community service announcement and a reminder that yes, Virginia, global warming is real. And it’s happening right now to the planet you’re on. See what you can do to help.
Each fortnight we speak with a special guest in the fields of radio astronomy, optical astronomy, space science, or particle physics. Our featured guest today is doctoral candidate Sophia Nasr. She’s a passionate diversity advocate and inspiring cosmologist who gives us an awesome introduction to the latest research into all types of dark matter and why self-interacting dark matter is such a productive field of research.
And we’ll finish up as usual with our Astrophiz News highlights from this golden age of astronomy, space science, and particle physics. So let’s zoom across a few time zones now and talk to Sophia, who is currently in Poland.
Hello, Sophia.
Sophia: Hello, Brendan.
Brendan: Today we are speaking with Sophia Nasr, who is a graduate physics student doing her PhD at the University of California. And she’s working on her PhD in cosmology and astroparticle theory with a focus on researching…
Sophia: …interacting dark matter.
Brendan: Great to have you on the show, Sophia.
Sophia: Thank you so much.
Brendan: So before we talk about your cosmology and self-interacting dark matter research, can you tell us where you grew up, please, Sophia, and tell us how you became interested in science and space in the first place?
Sophia: Yeah, so I grew up and I was born in, in fact, Toronto, Canada. And I was raised with a father who had his PhD in math. So he was a math guy. And I was raised around that. So it was mostly math that brought me the love for the science kind of thing.
Also, my mom would take me out on meteor showers and stuff like that. So I really appreciated the night sky. I appreciated things like black holes and the stuff we really didn’t understand. But I think it was really the math that got me when I was a child. Thanks to my dad. Thanks.
Brendan: And it’s probably paying big dividends now. So please tell us a little about your school days and your early ambitions. And did those ambitions change?
Sophia: Yes. During elementary school, my dad would teach me math ahead of the curriculum. And I guess you could call me at that time somewhat of a math nerd so that when I wanted to play games, I’d have my dad make me a math test. And I really, you know, I grew—I grew an appreciation for it. I just really—I really was fond of numbers. I really loved them.
But as I grew, you know, when you’re kind of going into high school, I was split between Toronto and Toledo. I started high school in Toronto and then I moved to Toledo, Ohio, where I finished my high school. I was actually kind of a rebellious high school kid.
All in all, let’s say that my ambitions did change because I was raised, you know, with math, but I was also raised with this idea that my dad wanted me to be a medical doctor where, you know, as a medical doctor, you have to deal with things like blood and all these things that I actually couldn’t deal with. So I realized that as I was growing, that blood just wasn’t for me. I couldn’t, you know, do things like surgery. I couldn’t do that stuff.
So when I entered undergrad, I did so with the sort of outlook of, you know, looking to find my own passion—to like find out what got me. And I entered York University in Toronto as an undecided student. And I came across a club called the Astronomy Club where I started to attend. I attended the talks. I attended the club meetings, the stargazing, extracurricular things. And I think that was where I realized that astronomy is something that I really wanted to do. So to be succinct, I really like to say that the beauty of the cosmos led me to astrophysics, but then it was learning about the physics that kept me there.
Brendan: Fantastic. So in Toronto, an undergraduate science degree with specialized honors in astrophysics at York University, then down and right across the west coast of the USA to UC Irvine to do your PhD. Now, how did that come about? Was there any culture shock moving down there, or is university life ubiquitous?
Sophia: I think I was lucky to be at York at the time that I was, because during my third year as an undergraduate student, we had a new professor come in. His name was Sean Tulin. And this was a professor who happened to do research on dark matter. And so when he came and he kind of told us about what he does, it got me interested immediately. And in fact, he became the most wonderful research advisor and mentor to me that I could have ever asked for after that.
And it was with him that I began to work on this weird type of dark matter called self-interacting dark matter that we’ll talk about in a bit. But it was him that encouraged me to apply directly to the PhD rather than going to a master’s program first. And he recommended UC Irvine, which is where I’m at right now, as one of the places that I should apply to where one of his colleagues, Manoj Kaplinghat, was working as a professor who also did work on self-interacting dark matter, which I’ll just call SIDM from now on.
And this is actually one of my top choices. And luckily, I ended up being there. And I’m very happy to be here. I was also lucky… I feel I’m very, very lucky and very fortunate to have been part of a cohort that is one-third women. And generally, the entire cohort, all of us get along very well. And we’re pretty proactive in making the graduate student life an inclusive and nourishing environment for students, particularly women and people of color, which is very important to me as an Arab woman of color.
So I couldn’t ask for more. I really love where I’m at. And in terms of cultural shock, I don’t think so. I think it’s been wonderful in every way because, you know, being in Southern California, first of all, you know, the university life is wonderful. Plus, you get weather that kind of cancels out the winters, which I am totally happy with, because I never liked winter. So I couldn’t be happier.
Brendan: Fantastic. So you’ve found a wonderful supervisor. Now, what about your doctorate itself? What’s your ideal timeline?
Sophia: The ideal timeline completing the doctorate degree would be five years. But as we all know, graduate life is, you know, can take many turns. So it could take slightly longer. But of course, I’m aiming for five years. That’s my ideal timeline.
Brendan: Yep. Okay. Now, we always like to put our propeller hats on, especially when we talk to cosmologists. So before we dive into SIDM, let’s go from the very large scales to the very small. Can you give our listeners a primer on galaxy clusters and cold dark matter, please?
Sophia: Oh, this is my favorite stuff. Yes! So let’s start with the beginning. OK, so in the early universe, after the Big Bang, where things started to coalesce, we had a sort of dense soup of matter, which includes both normal matter—so the stuff that you, myself, the stars, things that we can see are made of—as well as dark matter and radiation, where radiation is photons. This dense soup of stuff in the early universe… and we know that matter in general, both normal matter as well as dark matter, interacts with gravity. So what it wants to do under these conditions is that it wants to coalesce.
But when regular matter tried to condense in the early universe, it faced a problem, because as we know, normal matter interacts with photons. And there was—there were a lot of photons, a lot, a lot of radiation in the early universe. And when it tried to sort of condense into these little dense pockets in space, it couldn’t do that because it faced this stuff called radiation pressure due to the photons. So what would happen is that when it would try to condense, it would get pushed out of these little pockets, so it couldn’t form any dense pockets in the early universe.
Now, switching over to dark matter, which we know doesn’t interact with light, but does interact with gravity. When it tried to coalesce, it had no problems with the radiation pressure because it didn’t affect it. It didn’t interact with light. So it was able to coalesce under gravity. It was able to condense and form these little dense pockets that form the seeds for where galaxies and stars would form from regular matter and form the universe that we see today.
Now, in order for this to work and create a universe like the one that we see today when we look out into the universe, like including galaxies and galaxy clusters, we require that dark matter be cold. And what does that mean? When we say cold, when we refer to dark matter, we mean that it’s not relativistic. That’s to say that it doesn’t move at a significant fraction of the speed of light. So what cold means is that it’s slow-moving. And if it’s slow-enough moving, then it has enough time from the beginning until today to have condensed enough to form the structure that we see today. And that’s what we mean when we say cold dark matter.
And so with this kind of dark matter, we end up with these giant clusters of galaxies and galaxies that we see today where dark matter holds all these things together. And so here we are.
Brendan: Fantastic. Okay, so let me go a bit further. And you’ve introduced SIDM, self-interacting dark matter. Now, another important acronym is WIMPs. We’ve interviewed dark energy and dark matter researchers, and some of the researchers looking for dark matter have built detectors deep down, literally in the bottom of gold mines. Now, ATLAS is searching for dark matter in the LHC. Kate Pachal from two episodes ago is looking for dark matter in the Belle II Collider up in Japan. The LUX detectors have drawn a blank for now.
And for a while, WIMPs were a great target particle. Could you introduce our audience to WIMPs? And more importantly, give us an overview of your research into SIDM, self-interacting dark matter.
Sophia: Sure thing. So WIMPs, an acronym for Weakly Interacting Massive Particles, come from this theory called supersymmetry. Basically, supersymmetry says that every particle that we know in the Standard Model, so every particle that we understand, has a partner that’s heavier than it, and that’s its supersymmetric partner. And so in the early universe, particles would decay and decay and decay and decay into lighter and lighter and lighter particles. But of course, there’s only so much you can decay until there becomes a point where you can’t decay any further.
When a particle decays to a point where it can’t decay any further, we call that the lightest supersymmetric particle. And that is a particle that can no longer decay and is, of course, sitting there doing nothing because it’s just left there in the universe, having decayed to a point where it can’t do anything any further. And it happens to be a wonderful candidate for dark matter because it just sits there and there’s a lot of it. And that’s actually what this WIMP or Weakly Interacting Massive Particle is: the lightest supersymmetric particle. So that’s the idea of WIMP. That’s where the WIMP idea comes from.
And then now we’re left with this gigantic amount of stuff, which really is kind of what our universe is filled with. 85% of the matter in the universe is dark matter, and 25% of the universe’s contents is dark matter. 5% is us. 70% is dark energy, which we still don’t understand either. So we really don’t understand much about our universe. And that’s actually a really fascinating part of all of this.
So, okay. So WIMPs are also something that make up CDM, cold dark matter. So I’ll just refer to that as CDM from now on. But with a caveat: when I say cold dark matter, what we really mean when we say cold dark matter is cold, collisionless dark matter. So when I say cold collisionless dark matter, that means that these dark matter particles do not collide with other dark matter particles. They don’t interact with each other at all. They’re collisionless. That’s what CDM stands for.
And it’s extremely successful on large scales. When you simulate a galaxy with this type of dark matter, cold collisionless dark matter, CDM, you get back a universe that looks just like the one that we live in today on large scales. Problems happen when you start to zoom in and look at small scales, like, for example, dwarf galaxies, which are galaxies that are significantly smaller than the galaxy that we live in. So like satellite galaxies to us.
Brendan: Yep.
Sophia: And when you look in at those, the galaxies that CDM forms, that cold dark matter forms, have way too much matter in their centers compared to observations.
Brendan: Yep.
Sophia: Observations tell us that they’re not so dense in the center, whereas these simulations of cold collisionless dark matter show us that, well, you get galaxies that are super dense in their centers.
So in order to solve this problem, this is where self-interacting dark matter was born. So self-interacting dark matter, or SIDM, is cold dark matter, but it’s cold and not collisionless. So it does experience self-interactions. It does interact with other dark matter particles. And these interactions actually allow it to thermalize galaxies. For example, when you look at, you know, a dwarf galaxy, if you turn on self-interactions in a simulation, you find that you start to form dwarf galaxies, small galaxies that look like the ones that we see when we look at observations. And that’s great, because it solves that problem.
But just like, you know, in anything that we do, you can’t solve one problem and then break everything else, right? Because as I just mentioned, CDM works very well on large scales. What that means is that if you look at, you know, galaxy clusters or very large galaxies, those ones are very happy having dense cores. They’re very happy, excuse me, having dense centers. They’re happy to have a lot of stuff in the centers of their galaxies. They’re happy to be dense there. Only dwarf galaxies aren’t.
So self-interacting dark matter has this feature that in order for it to work, it should have a velocity-dependent cross section. Now, a cross section is something that you can think of as, say, the likelihood that two particles will interact. If you were to take two marbles and throw them towards each other, the likelihood that they will interact—because their cross section or the area, the cross-sectional area that each of them have is small—is small. So they might not interact with each other. But if you take two basketballs and throw them towards each other, the likelihood goes up that they will actually collide with each other.
And so for SIDM to work and solve these problems, you have to have a really interesting dependence on velocity such that the cross section of interaction decreases as the velocity increases. How does this make sense? Okay, well, if you have a dwarf galaxy, it has much smaller mass. And if it has a much smaller mass, then it has a smaller gravitational potential, which in turn means that the particles that are in this gravitational potential or in this gravitational field will move with smaller velocities. So then having that small velocity gives it a larger cross section of interaction.
Now we move to large scales, galaxy clusters, which are like 10 to the 15 solar masses. Dwarf galaxies are more like 10 to the 9 solar masses. And then galaxy clusters are more like 10 to the 15 solar masses. These are really giant structures in the universe. So really large gravitational potential, which also means that particles that are in this gravitational potential move much faster because velocity also depends on the gravitational force. And the larger this velocity that they have in this potential, the smaller the cross section.
And so these galaxies are very happy with a small cross section and then everything works out fine. And that’s basically why SIDM exists. Why self-interacting dark matter exists is to solve this problem, and a velocity dependence is really important for SIDM to work.
Brendan: Fantastic. So getting things to work on both scales is the challenge.
Sophia: Yes. You don’t want to fix one problem and break everything else because we know that CDM is a very successful theory. So fixing a problem on small scales that then introduces problems on large scales isn’t fixing the problem. It doesn’t solve anything, right? You need to be able to fix a problem on all scales so that you end up with a universe that looks like the one that we live in today. And to do that, we introduce a velocity-dependent cross section.
Brendan: That’s just beautiful. I can see how your modeling and mathematics comes into all of this. Now, how would you summarize the current state of play for dark matter research as a whole?
Sophia: Oh, currently dark matter research is booming! Like, we have no idea what this stuff is, but we really—like, physicists are working very hard to try to figure this stuff out. I mean, it makes up a huge component of the universe. It’s one of the most pressing mysteries that physics faces today. We don’t know what it is. It’s evaded us for so many years. And, you know, and we still don’t know what it is yet.
We’re coming up with better ideas on how to attack the problem to answer this pressing question, but we really don’t know what it is. And I think it’s super exciting to be able to be part of this venture to understand one of these most pressing mysteries in the universe.
Brendan: That’s fantastic. You must be having so much fun. That’s brilliant. Now, as well as being a doctoral student doing this amazing research, you have some other wonderful passions that drive you and take you on fabulous journeys. Can you tell us how you got into planetary imaging and your citizen science work?
Sophia: Yeah, so the love that I have for that is Cassini. The Cassini mission, it touched my heart in so many ways. Saturn has always been my favorite planet, but then, you know, with Cassini having shown us even more of its beauty, I just fell in love with that whole mission. When the mission began to head on its path towards its end, where they started to send it on its orbits into Saturn, I kind of just realized that I wanted to be a part of bringing the last images that we are going to get of this wonderful planet that we still don’t understand. And I wanted to bring it to color for people. I wanted people to be able to appreciate and see what it looks like for what we have as eyes. These are eyes for human beings that are sitting orbiting around Saturn that will soon blink out. And I wanted them to see every moment of it before that happened.
And that’s why I began doing this. I have to thank Emily Lakdawalla. Emily Lakdawalla had created this wonderful guide to teach people how to do image processing. But the person who helped me the most is my friend Jason Major, who is fantastic at image processing. He spent so much time with me and taught me things that I didn’t know, like things that would help me process these images better and bring them to color in more of a true form. I have to thank these people. They were very wonderful, and it’s been so fantastic to be able to take part in that.
Brendan: Fantastic. Another powerful string to your bow is your outreach work as Astro Party Girl. And I’m not sure if everyone understands that the “party” stands for particle, but you’re an inspiring advocate for science, for equality, for social justice, for astronomy, for astrophysics. You do work on television, in multimedia productions, and extensively on social media, Twitter. Why is outreach such an important part of your life?
Sophia: Yeah, so I think people are usually introduced to STEM fields, physics in particular, in this intimidating fashion. And so I want people to see the beautiful side of physics. I want them to see that. I don’t want them to be inundated with all the math-heavy stuff that we’re bombarded with when we think about physics. I don’t want their vision to be clouded by it.
I want them to see what lies beyond it because there is so much beauty beyond it, beneath the enigmatic equations. What does it mean to live in a universe that is flat? What does it mean to say that mass bends space-time? And how does that create these arcs that we see around these giant clusters of galaxies that we see in these beautiful images? How does that happen?
I want people to understand this. I want people to revel in it, because there’s so much to be inspired by, and it just gets lost in all the math. And I want to demystify that. That’s why outreach is important to me.
Brendan: Fantastic. And I can hear the awe in your voice. Now, the mic is all yours. And you have the opportunity now to give us your favorite rant or rave about one of the challenges that we face in science, in society, or science denialism, or science career paths, or equality, or equity and diversity on our quest for new knowledge, or even science outreach itself. The microphone is all yours.
Sophia: It would be unsurprising for me to point out that one of the biggest issues that we face today that bothers me and that touches me as a woman is that there are very few women in physics, in professorial positions in physics, to resolve. There are few people of color in professorial positions in academia where people can look up to. And this is a really big problem because, as you know, as a woman in physics myself, if I was, you know, I took my classes, I didn’t really have—I think I had one professor who was a woman to look up to, and that was about it.
We don’t have women as figures where we can see ourselves. Representation really matters. And when you go to children and ask them what the typical physicist looks like, the majority will come and say that, well, it’s a—it’s a white old man in a lab coat with gray hair. Yeah, well, that’s not what we look like. I’m not a white man. You know, I don’t wear a lab coat. I have pink hair. I’m a woman, an Arab woman of color—Polish-Arab-Canadian woman of color, white-passing—but that’s—that’s what I am.
And I would have appreciated having to, you know, having role models to look up to. And I think that children and just the younger generation need to have representation so that they can look up and say, “You know what? That person looks like me and they’re doing this. So if they’re doing it, then I can do it.” Because if you don’t have that, it often kind of tells you that, well, that doesn’t look like me, so maybe I don’t belong there.
And we need to change that so that people can see that they can make it, too. But not only that: making it a friendly place for women and people of color. These are really important things that we need to work on. And we’re starting, but we’re not anywhere close. So these are my biggest rants. If you follow me on Twitter, I’m sure you’ve heard a lot of it.
Brendan: Exactly. And we have our own diversity policy here, and that’s reflected in the diversity of the 90 people we’ve interviewed. Thank you so much for that.
Now, is there anything else we should watch out for in the near future? What are you keeping your eye on, Sophia?
Sophia: So, aside from trying to figure out what this weird stuff that dark matter is… what I want people to pay attention to that I’m going to be coming up with is that I’m going to be doing more videos. I’m going to be doing science communication in the form of videos because I feel like I can get to the audience—I can get to them with my passion a lot more directly through videos where they can feel it. And I’m very excited about that, and I want people to know about that.
Brendan: Fantastic. Thank you so much, Sophia Nasr. On behalf of our listeners, it’s been really fabulous speaking with you. Thank you for your time. Thanks for helping us organize this chat together. Best of luck with your doctorate. We’ll encourage all listeners to follow Astro PartiGirl. That’s at A-S-T-R-O-P-A-R-T-I-G-I-R-L on Twitter, and you’ll also find her on Insta and Facebook telling fabulous stories. Thank you so much.
Sophia: Thank you. You too. Thank you for having me.
Brendan: Okay. Bye now.
Sophia: Bye.
Brendan: Now we have an apology from our observational guru, Dr. Ian “Astroblog” Musgrave, who had to unexpectedly fly up to Brisbane, and we send our best wishes to Ian and his family.
So I cranked up Stellarium and can report that Jupiter and Saturn are still high in the sky and always great to observe, even with the naked eye or just binoculars. And for those with telescopes, I usually just envy you, but I’ll soon be joining you because my restoration of a historical 1895 10-inch reflector with an EQ mount has just moved another step closer after getting some fabulous advice and an eyepiece and a secondary mirror from Dr. Barry Clark, who is on the restoration team for the Great Melbourne Telescope.
So, back to observations. In the Southern Hemisphere, Jupiter sets around midnight, followed by Saturn around 2:00 AM, and moonset is close to dawn at the moment. For Northern observers, Uranus is your only planet up there for those with telescopes, with Orion’s rigel and Betelgeuse looking magnificent. The full moon is in two days’ time, so it will outglare many fainter objects in the night sky for a week or so, but will itself be great to look at. The new moon is approaching after that with skies getting darker, and towards the end of the month, many of you with a low Western horizon will capture the beauty of the finest crescent moon near Mercury just after sunset.
The September equinox is on the 23rd, a signal for the change of seasons on most parts of the planet, but for some strange reason, our Australian seasons change on the first of a month. Go figure. We also have lots of animals that will want to kill you. If anyone knows why our seasons change on the first of a month, please let me know by leaving a comment on our astrophiz.com website.
For those who enjoy watching live rocket launches on the internet, put September 25 at 13:57 GMT into your calendar to watch a Russian government Soyuz rocket at the Baikonur Cosmodrome in Kazakhstan launch to take the crewed Soyuz MS-15 spacecraft to the International Space Station with members of the next expedition crew. The capsule will remain at the station for about six months, providing an escape pod for the residents.
For citizen scientists, there’s a nice opportunity to participate in the Globe at Night Dark Sky project, which is concerned with light pollution. For those in the Northern Hemisphere, you’ll be asked to report on what you can observe in the constellation Cygnus between September 20 and September 29. And for Southern Hemisphere citizen scientists, you’ll be asked to report on what you can observe in the constellation Sagittarius on the same date range. To contribute to this worthwhile project, Northern observers can go to tinyurl.com/darkskynorth and Southern observers can go to tinyurl.com/darkskysouth, and they’re both all lowercase or one word.
And now to the news.
First up, it looks like we have an amazing new interstellar visitor. Congratulations to Gennady Borisov for his discovery of Comet C/2019 Q4 (Borisov), the first interstellar comet ever found and a truly sky-breaking discovery. The Minor Planet Center has published the official announcement a few minutes ago. The object was discovered 12 days ago by Gennady Borisov using his custom-built 0.65-meter telescope. At discovery, it was three astronomical units from the Sun. It came from the direction of Cassiopeia, near the border with Perseus, and very close to the galactic plane. It will come to perihelion, closest approach to the Sun, around 7th of December 2019. Confirmed as a comet by JPL and others, and apart from an unexpected fading or disintegration, this object should be observable for at least a year.
Reports have also just come in today that water has been detected on a distant exoplanet. The reporting on this discovery is all over the internet and all over the place in terms of accuracy. No, it’s not an Earth-like planet. No, it doesn’t have water on it, because it’s most likely a Neptune-like planet with no actual surface, and you wouldn’t survive long enough there if you were there to develop any habits. It’s becoming clearer and clearer that terms like “habitable” and “Goldilocks zone” aren’t really effective tools for accurately communicating science to public audiences. If you want to get a lowdown on habitability and exoplanets, you couldn’t do better than to follow Professor Jonti Horner and Dr. Elizabeth Tasker on Twitter, or hear from them directly by checking out their episodes at astrophiz.com.
It was also sad to hear that Israel’s moon landing has run into problems, but our fingers are crossed for them, and other news from the Moon is that the Chinese rover has detected some strange gel-like substance in a crater.
Next, from the Xinhua News Agency in China, a discovery that may help unravel the long-standing mystery of FRBs. Chinese astronomers have detected over a hundred repeated fast radio bursts (FRBs). These particular FRBs are mysterious signals believed to be from a source about three billion light-years from Earth. The Chinese scientists have installed a highly sensitive FRB back-end on a 19-beam receiver on the giant telescope—it’s the 500-meter Aperture Spherical radio Telescope known by the acronym FAST. FAST observed an FRB source named FRB 121102, which was first discovered by the Arecibo Observatory in 2015.
From late August to the beginning of September, more than 100 bursts were detected from FRB 121102, the highest number of bursts ever detected so far. The FRB back-end system has high-efficiency real-time pulse capture capability and can observe in parallel with most observation tasks. It will play an important role in the discovery of new FRBs, improving the position accuracy and capturing the high-resolution absorption lines generated by FRBs in real time, researchers said.
Given the significance of this source and its now apparent active state, FAST is carrying out more monitoring. Located in a naturally deep and round karst depression in southwest China’s Guizhou province, FAST was completed in September 2016 and is due to start regular operations this month. Astronomers from more than 10 countries and regions are making observation plans for FAST in order to best apply the unprecedented power of this telescope. Scientists believe that—and I quote—”more discoveries will be made with FAST.”
No shit, Sherlock.
So, we’ll see you in two weeks.