Our Boundary to Interstellar Space: A New Regime of Space Physics

alright let’s get started hello everyone and welcome to another installment of the interstellar probe study webinar series my name is James Mastandrea and I’m the deputy study manager for the interstellar probe study thank you very much for tuning in to today’s webinar we have a wonderful panel presentation today on our boundary to interstellar space a new regime of space physics and after the presentation we will have a question and answer session before we start I would like to outline the logistics of today’s event as a member of the audience your audio and video are off during the presentation please submit your questions and the question and answer feature and please indicate which panelists your question is for you may also upload questions during the question and answer session I will start with the questions with the largest amount of uploads and proceed down the list also for more information about the interstellar probe study and for information on future webinars please visit the inner solar probe study website and now I’d like to introduce today’s speakers dr. Elena Pavano Cova is a space physicist at the John Hopkins University Applied Physics Laboratory with research interests in the physics of the outer and inner heliosphere she’s the deputy pie on the heliophysics mission of opportunity Sheila and his elite scientists for Helio physics on the interstellar probe study at APL professor Ophir is a professor of astronomy at Boston University and the PI of an acid drive initiative called shield which stands for the solar wind with hydrogen ion exchange and large-scale dynamics that is a multi-institutional team with the goal to improve the modeling capabilities of the heliosphere professor Ophir has held many prestigious leadership positions including the chair elect of the American Physical Society topical group in plasma astrophysics and has chaired the outer heliosphere sub panel of the decadal survey in space physics of the solar and heliosphere heliosphere panel dr. Jaime Rankin is currently a postdoctoral research associate at Princeton University and received her PhD from Caltech and 2018 during her graduate studies Jaime contributed to the development of the high-energy particle instrument epi high for the SS instrument onboard Parker Solar Probe at Princeton she continues to study the outer heliosphere and the and the interstellar boundary using data from both Voyager and ibex she also works on Parker Solar Probe and is the deputy instrument lead for the solar wind and pick up I an instrument on IMF and with that dr. Pavone a Cova the virtual floor is yours Thank You Jace and hello everyone so I would like to give a brief overview of the ongoing study of the future space mission interstellar probe what this mission will go to the interstellar space and discover what’s out there and how does the Sun interacts with the interstellar medium to form a complex and dynamic bubble which we call heliosphere interstellar probe will be faster and further than any spacecraft we ever launched an idea for this mission has been with us with for 60 years recently APL has been contracted by not circular physics division to do the study how we can turn this mission into reality it’s really amazing than that in the first two years of the study over 200 scientists and engineers for more than nine countries around the world actively following or providing inputs and ideas into the interstellar probe concept study so what is the interstellar probe since the beginning of the Space Age humanity has dreamed of going to another star and since 1960s scientists have discussed of going beyond the heliosphere to the unexplored interstellar space we are not going to another star but interstellar probe is the first step to the kabocha galaxy interstellar probe will travel through the boundary of the heliosphere into the interstellar medium to about 1,000 astronomical units from the Sun we are not a starship an interstellar probe would be a large strategic mission that uses available technologies to achieve asymptotic speeds by a factor of two three greater than those of Voyager 1 and 2 spacecraft who discover the heliosphere boundary and exploring the doorstep of interstellar medium the compelling science about the nature of the global heliosphere remained with us over the decades and is completely enabled by going to new unexplored place for the first time we will discover how our heliosphere the only habitable a stress fear we know today looks from outside and what lies beyond our speakers today Morocco and Jamie will talk to you about major unsolved science mysteries for planetary science and astrophysics there are certainly very make opportunities for Kuiper belt object flybys in the outer solar system

and for going beyond our own obscuring the Oracle cloud to open up the window to early galaxy formation and lastly interstellar probe also paves the way for the next steps on longer journeys ahead in many different ways scientifically technically and programmatically and next slide please James the key world for the mission study is pragmatic we have said the high-level requirements to bound the concept study first we need to have all technology ready for flight by 2013 which is 10 years from now we need to have the capability to operate and downlink out to 1,000 astronomical units and we require no more than 600 watts at the beginning of the mission and lastly the mission lifetime is no less than 50 years miss James so in this image you are looking at the layout of the solar system the heliosphere boundary and the local galactic neighborhood on a logarithmic scale the solar wind makes supersonic Li away from the Sun well beyond the orbits of the planets until it reaches the region where it interacts with the interstellar medium previous explorers Voyager 1 and 2 discovered that the solar wind decelerate sharply at about 90 economical units which marks the termination shock later in about ten years they cross the heliopause that separates solar and interstellar plasma particles the heliopause marks the boundary of our bubble our heliosphere if you all know Voyager 1 and 2 were planetary missions and fortunately became accidental interstellar explorers right now two voyagers are at 150 and 125 astronomical units from the Sun exploring in situ the very local interstellar medium just beyond visual asphere voyagers will likely operate for another five more years after flybys of Pluto and Kuiper belt object nu 69 New Horizons mission will explore the outer heliosphere plasma until about 90s on the Calumet and has a chance to cross the termination shock which is uncovered a number of mysteries showing that interactions between plasma energetic particles and magnetic fields at the heliosphere boundary marking a new regime of space plasma physics and our speakers today will talk to you in details about this her voyage is it took 30 years to get to the boundary region with conventional propulsion interstellar probe would explore this region after 12 years from launch and in just another eight years it will explore unknown regions in the interstellar medium where we’ve never been before next slide please so the primary mystery is that interstellar probe mission is going after is what is the global nature of the heliosphere how do the sun and galaxy affect the dynamics of the heliosphere and what is the nature of the interstellar medium and now I would like to turn into dr. Morocco over and she will talk about our u.s. field yes so much Elena and James for introduction so I would like to give you an overview some of the unknowns of the Heliospheric that we call the shield and I will talk why we say that is a shield I’m so next slide James so we know that most stars if not all stars have asked those fields around them and they come in all sorts of shapes and forms as seen as beautiful images that we have and a next slide so we we see them in different shapes around different types of stars but we have our only example of an habitable one that is ourselves we are searching for exoplanets around other stars but we don’t really know what are the conditions to begin life one of them we know is that all the stars and the exoplanets are embedded within osku spheres and we are we have with our own the heliosphere an opportunity to study astha spheres in a lot of details we will be never able to study atmosphere that we can only stay far away by measuring light so one of the thing we learn recently next slide please is that our heliosphere our own atmosphere shield 75% of cosmic rays up to 1 GeV and we know that these particles are a key fundamental part of creating life on earth and with the passage of Voyager by the heliopause we learn that the last layer of the heliosphere shields 75% we don’t really know is this shielding happen in other areas of the heliosphere we don’t even

know how it’s very with solar cycle and with other conditions but at least we have one data point showing how important those fields and heliosphere important for life next so this knowledge we learn not only with the in situ data from Voyager 1 and 2 shown here in the top left but also with global ena maps by ibex and Cassini and I will talk about this data in the next slides next and one of the thing to keep in mind that when we are trying to have prediction in understanding of the heliosphere we come to the realization that our best sophisticated models fail to explain not just any observation but key observations that describe the heliosphere here I’m showing you a panel of flows the radio flows in the middle panel and the tangential flows in the bottom panel measure the Voyager 2 in black and in Virgil 1 in red and you can see that they’re very different from each other and this flows that I’m showing here are in the last layers the same layer that shield the cosmic rays this is a rage of the Helio shades that I’m showing you the flows we don’t really understand why the flows the Virgin one and two are so different and we also those flows cannot be predicted by current models so it’s a problem the other problem that I’m going to point out later on in my slides that voyages were not as Elena said slotted to probe that region so they lack instrumentation to measure one of the key particles that carry most of the dynamics in the thermodynamics in the last layers that are pickup ions that I’m going to describe later on but those are energetic particles around kV and we don’t have instrumentation to measure them directly so there is a need to revisit this region with interstellar probes we know that new horizons have an instrument that measures these particles but new horizons won’t be able to reach to the interstellar medium it’s going to reach a little bit beyond the termination shock next so one so let me touch in some basic questions that we don’t understand and this is kind of embarrassing if you ask yourself do you know the shape of your house in your neighborhood yes you know it’s a box and here we are in in we are a very shape of the heliosphere we don’t really know we thought we knew but in the last year’s this shape and this structure is being challenged as a next slide please one of the challenges come form data and you think that data tell you the final answer but like as I will show you data in different energies give you different answers so the data come for energetic neutral atoms from Cassini this was published in by Daily News and on in 2017 so I already pointed out in 2009 that the heliosphere is not a comet-like shape with a tail extended for thousands OVU like showing the bottom right that this is a conic say if you type in google heliosphere you will see a comet like shape with a tail extending for thousands of you but the data by energetic neutral atoms point that is not the case and the heliosphere is feel like next however if you look at energetic neutral atoms in lower energies still this is consistent with a comet-like tail why that we still need to understand so and this was seen by ibex next now you said okay let me ask the Sara Titian the models what they say what is the shape of the heliosphere and there was no agreement so here if you look on the left side by the Moscow group here is by blood is Modine overall and on the right side by Nick Prague irrelevant all by the Alabama group they both get a comet-like shape and they have different abilities a radical assumption but they get a long tail our group is being advocating that the shape is more like a course sound like shown here in the middle very short almost like tailors on next slide one of the things that all the models agree so this is a relief at least we agree on something that the topology of the solar magnetic field is a backbone of the heliosphere this was kind of a surprise because the solar magnetic field is not the main dynamic actor here but turns out that in the heliosheath the pressure of the magnetic field is comparable to the

flows that are very slow so the solar magnetic field turns out to really shape the structure of the heliosphere and I’m showing here on the right hand side the magnetic field in grey by the Nick polka relevant I’ll model and in the left by our model in white and both structures you can see almost identical the magnetic field behave like a slinky bent by the pressure of the interstellar medium and our models including the moscow mode of show that the magnetic field can find the solar wind in the heliosheath so this is a new understanding next slide however what the consequences of that confinement still need to be understood we advocated in 2015 that though behave like Jets that they are confined and the interstellar magnetic field as shown here in the red lines flow between the heliosphere that is shown in yellow that is like a cone and the heliosphere is almost stainless in the sense that the solar magnetic field shaped the heliosphere in a constant like structure with the distance comparable to the nose into the tail next another problems of models are facing not just a very shape but how big is your house basically and how thick is your heliosheath this is the same Healy sheets that shield the galactic cosmic rays and we all the models no matter what recipe you put in it we are predicting thicknesses at our factor of two wider than the observations and even if you include the fact that the solar wind breathe in and out and time-dependent effect you cannot reconcile this fact so it’s indicating something exciting that there is some physics that is missing in all the models we are missing something you know understanding of the heliosheath next there are other problems that we are facing not just that we don’t know the shape of the house the thickness of the house now we don’t even know if the walls of the house the heliopause oppose or not it’s almost like you’re sitting in your house and you don’t even know if the weather is going to be cold or hot because you don’t know if the heliopause it’s going to shield particles or not if you look here in the passage of the heliopause by Virgil one shown in left and the passage of the heliopause shown by Voyager two on the right they’re very different I’m not going to go all the details but this panel show how much a galactic cosmic is came into the heliosphere and how much the solar particles on the bottom panels leaked out and if some cases like virgil one was very leaky in cases of where John was not leaky why is that so it’s mean that again the properties of the heliopause are not understood and and we don’t have a predictive models to predict the characteristics of the heliopause in all our Ito the longitude with different solar wind conditions for example next the other fundamental question that I touched in the beginning is about the pickup is the pickup balance of particles that are not the thermal component of the solar wind that is code shown here in this complicated plot but what suffice for you to understand that the blue region in this plot show the intensity of particle for energy that the Voyager is blind voyager measure the pieces of them to the left and to the right of this blue box but we think the particles on that energy range of the ones that play the key role in the heliosheath but Voyager doesn’t have an instrument to be able to measure that next what we do did learn and this is why we know that the picker pines are so important that when the solar winds slow down with respect to the galaxy and become subsonic it’s go from a very fast flow 400 kilometers per second to a slow 100 kilometers per second that shock to us for 80% of the energy not to the thermal cold plasma but to those energies that the Voyager is blind the pickup is and this is shown in this beautiful plot that John Richardson it all published about the crossing of the termination shock the prediction if all the energies would have gone to the code particles would have been that the temperature would be like the black diamond shown on the bottom panel but in fact the measurements show an order of magnitude cold this is a cold plasma and when you calculate you realize that the rest of the energy is hidden in this

spot where Voyager is blind next however if you use your best understanding of the pick up ions evolving and here we use some measurements very beautiful measurements of your Horizons is making at for tau from the Sun when you include them as a separate fluid in your models you separate the thermal and the pick up ions they a major effect so our concern that we had a prediction when we include the pickup ions the pick up ions they become energetic neutral atoms and leave the system deflating the heliosphere so it’s almost like you’re deflating your balloon and the heliosphere it’s still organized by the magnetic field but it’s very spherical at the nose and so we you can call it a deflated Co Sun but in any case what is interesting that the nose of the heliosphere is very spherical starting to look like the energetic neutral atoms in high energies okay next but we don’t what we don’t have in our models and neither we do have an understanding and how different processes like a connection like turbulence like a celebration of particles affect bigger Pines neither in the supersonic solar wind neither in the heliosheath where the solar wind becomes slow those are processes that you can theoretically simulate and calculate and you know that they can affect the appearance but we still don’t have a fully understanding what the effect is and how to cope with in the models we also don’t have the instrumentation on Voyager to really uncover if the connection is happening or not on either to measure the if to balance is happening so this is again another reason why to come back to that region with a modern instrumentation next and another question related with the pickup is that there is an old paradigm that the pickup ions are carried by the solar wind they come to this gigantic termination shock and are celebrated to mev energies what we call a normal lost cosmic rays and if you look on the Left panel those are intensity of particles for energy and this is a diagram almost like what you do you make I have a diet so before and after the diet so this is before the termination shock cross and after the termination show crossing and if you look at the piece of the normal loss cosmic rays you cannot even tell that there was a shock so what happened was a major surprise and next that the intensity of the normals cosmic race didn’t really change at the termination shock at around MeV and this complicated panel here by Allen comics shows that the intensity of the anomalous cosmic rays continued to increase until the heliopause until it’s dropped once we left the heliosheath so it seemed like those particles are accelerated in the heliosheath it’s or somewhere else in the termination shock not close to the Voyager 1 and 2 spacecraft and this has really bad implication like many other questions that I touched already for astrophysics as well and for space physics in general for do we understand the cellulation of particles in shocks for example okay next now that I touch on the blood existential questions of understanding in the heliosphere we come to the last piece that how the heliosphere interact with interstellar medium so if you would have asked us before voyagers cross does interstellar medium we might have predicted that locally just outside the heliosphere the interstellar medium will be somewhat quiet but this is not the case next slide and what the Voyager 1 and 2 spacecraft uncovered and this is a beautiful panel by duncan net that show that this is the plasma measurements ahead of the heliopause and voyager 1 and 4 all the time still now you can extend this plot further and Jamie ranking is going to talk more about it there are several sharks shown in the top panel and these green and red blobs that intercept interstellar medium the perturbation that we think driven by the solar wind we don’t really understand that but it shows if you see the intensity of particles not isotropic their anisotropic it mean that the solar wind continued to influence the interstellar medium region quite substantially for at least 30 au ahead of the you pause we don’t really know how far this influence extent and this again it

has a broad implication for how stars in general interact with interstellar medium so again we need an interstellar probe to go out there and go way beyond 30 you to really probe that region next slide in the last question to not just how far we perturb the interstellar medium but what happened with the magnetic field that comes from the galaxy how does it change and drape around stars and Isis fields in heliosphere we had a prediction that the magnetic field out there it’s very different than the solar like and it’s going to attain pretty dramatically as it treats the heliopause and this was one of the signatures that we weighed it as soon as we will go out of interstellar medium we will see rotation of the magnetic field and next slide and in fact what we saw is nothing like that it’s similar to the normals cosmic ray story if you would be just looking at the magnetic field angles shown here in lambda and Delta the give you the direction before and after the heliopause this angle barely change and they’re so low like it’s like the magnetic field in the galaxy outside in the local interstellar medium is so low like when it’s going to what a to its original direction we don’t know and how far we have to go to start seeing this rotation it’s another open question so I want to leave your next slide with just an idea to think that a proposed trajectory of Anita Sela probe I will advocate she goes to the flanks not to the notes that we still have a lot of mysteries don’t cover but it will be a new Region II space at neither Voyager 1 and 2 left and we will probably discover a new region in space with flows and particles if we have been visited with an instrument that can measure pick up ions would be amazing we will be probing the draping of interstellar magnetic field and probably where the new most cosmic rays are accelerated so I will leave you with that I already made my points that we need to revisit that and pass it to Jamie and Rankin thank you thank you very much professor Ophir and now for dr. Jamie renkins presentation Thank You Merle thank you James today I’m going to talk about solar transients through the heliosphere and beyond and how they uniquely enable us to view our bubble between the stars not only from the inside out but also from the outside in next slide the pot on the left is my favorite summary of winters journey through the solar system taken by Voyager 1 using cosmic rays which a particle is energized by external sources that are spread throughout the galaxy time is shown on the horizontal axis remember both voyagers are moving further and further outward so time represents increasing distance from the Sun and then count rates are shown on the vertical axis the there are a number these are the number of cosmic rays that are detected at spacecraft in a given second as Merle mentioned earlier this plot illustrates how much the heliosphere shows us from external radiation from 1977 to about 2004 you can see clear periodic structures indicative of what is called solar modulations you see cosmic ray intensities behave opposite to the solar cycle a peak at solar minimum when the sun’s output is the weakest and they dip at solar maximum when the solar output is the strongest and overall periodicity matches that of the solar cycle which is roughly 11 years around 2005 Voyager beginning of 2005 Voyager crossed the termination shock and arrived in soar when subsonic region known as the heliosheath where the pattern is no longer obvious but we do see still see a clear trend of cosmic recounting rate that increases as voyager 1 moves away from the sun finally towards the end of 2012 where the one crossed into the interstellar medium we can see that from the inset plot on the bottom right and you can see that the cosmic rays are very steady and quiet unchanging compared to those preceding measurements so this begs the question that’s captured on the cartoon in the cartoons on the right hand side what’s out there that’s interesting in interstellar space is it simply a vast cosmic emptiness filled with lots of cold uninteresting particles actually to our surprise found at this region which we called a very local interstellar medium it’s still highly influenced by the Sun despite the fact that we have now crossed beyond the Suns in the two and plasma boundary next slide one example of the activity out there was captured by boy to one’s radio

instrument which directly saw emissions caused by unstable beams of electrons large radio missions similar to the events shown here were first seen back in the 90s early 90s by both woods or spacecraft following major solar events and these emissions were amongst the first hints of unusual activity occurring far beyond the outer planets next slide another example of time bearing changes in the very local interstellar medium occurs in the magnetic field although the direction of the field did not change when voyager 1 first arrived the field strength does vary due to shocks and as we can see most clearly from the top panel of the plot there’s an onset of two large shocks marked by the vertical lines in front of sections 2 & 4 so there’s a sudden increase in magnetic field and all of some aspects of these shocks may seem familiar to those who study such things closer to the Sun they’re also strange quite strange they’re very weak and there are thousands of times thicker than their near earth counterparts and the rise in magnetic field takes 3 to 5 days whereas closer to the Sun not only might only take minutes next slide we also see evidence of how both low and high energy particles get energized by these very weak shocks in fact that’s how the radio emissions are produced beams of low energy electrons gain energy at the shocks boundary Don Gurnett and collaborators in 2015 study that and hypothesize that particles could be energized in the similar way both low and high energy particles and they drew from analogous effects observed much closer to the Sun the diagram on the top left shows that as a spacecraft approaches one of these shocks it will encounter filled lines that are connected to different places along the boundary and particles energized by the shock will travel along the field lines and eventually reach the spacecraft and be observed well before the shock itself arrives evidence of this timing is shown in the plot on the right the talk kind of pretty depicts the cosmic ray of protons in the middle panel shows electrons both millions of times higher in energy then the plasma electrons responsible for the radio missions shown in the bottom and you can see that the cosmic rays arrived first in the top and middle panel and then the spikes of the plasma oscillations bottom and then eventually even though it’s not shown the shock itself crosses the spacecraft next slide finally there’s the unanticipated discovery of cosmic ray anisotropies this is the topic of my thesis work at Caltech under dr. ed stone new son it’s not uncommon for cosmic ray intensities to be reduced following a shock event although these are analogous they’re also very unusual because the intensities appear steady-state normal in all directions except perpendicular to the magnetic field the top panel illustrates this using the LACP instrument on voyager 1 which consists of double-ended telescope that steps in 45 degrees sectors you can see that the intensities in the red and green are very steady except for occasional shock spikes while the intensities in blue which is when the telescope is pointed perpendicular to magnetic field they show unusual variations that lasts from 250 to over 600 days in the middle plot shows an all-sky view from detectors on a second cosmic ray instrument CRS and so we have two instruments that agree about the structure and the statistical significance of this never-before-seen physical phenomenon the bottom panel shows the view from one of the fixed telescopes on the CRS instrument and that telescope happens to be pointed just off from the magnetic field and it doesn’t see any effects from the anisotropy but we do see occasional dips that occur during spacecraft calibration maneuvers and during these maneuvers the telescope does happen to overlap with that 90 degree pitch angle region in this view next slide in fact using these calibration maneuvers where in spacecraft rotates about its sun-facing axis we were able to confirm that the dropouts are in fact centered on 90 degrees with respect to the magnetic field and we also showed that this region and so that you can see that with the red line and we also showed that this region of affected particles is

roughly 20 degrees wide it appears that all particles outside of that are unaffected and although for the most part these events appear related to the passage of weak shocks many details of their underlying physics remain unresolved next slide this pot shows these of different telescopes on the same instrument CRS during other periods of spacecraft viewpoint the black blue and green lines were taken by a telescope the points just off of the 90 degrees during these particular maneuvers it measures low and high energy protons which are blue and black and then low energy electrons screen the plot in the red was taken by a telescope it’s solely dedicated to measuring electrons not happen to be pointing directly at 90 degrees ensure we find the electrons that are in the green in the red are not experiencing and I start to pee while protons and the black and blue are seeing me we do not know why this is next slide so here’s a summary of these transient events what causes these disturbances the answer is the Sun a solar events flares coronal mass ejections and other types of solar energetic particle events sweep out from the Sun the quickly moving ones overtaking the more slowly moving ones emerging two large structures the resulting merged interaction regions can survive out to the heliopause and transmit pressure waves into the interstellar medium this in turn produces the disturbances I’ve described so even beyond the sun’s material and plasma limits we see many examples of how the Sun influences its surroundings in surprising ways next slide so how do we know these events come from the Sun here we step back from the interstellar medium and place ourselves on just on the other side of the boundary and who is she focusing on the left figure Voyager twos working plasma instrument found evidence of these merged events and in terms of large pressure pulses in the plasma the plot on the right is a simulation which which takes events from the Sun and propagates them all the way out to the interstellar medium these simulations could actually recreate the timing of the shocks and radio missions in Voyager 1 they even successfully predicted a follow-on event next slide in fact we have evidence of an event the first crosswords to in the Huey sheath and disturbed the cosmic rays shown in the blue paw on the bottom of the figure the structure then went on to transmit a pressure wave into the interstellar medium which arrived at Voyager 1 only 130 days later that’s the top in red in fact these two cosmic ray profiles showed a 91.2% similarity and beyond this really cool finding we used the observations to infer a never before measured quantity the hughley’s total pressure which when balanced with a nurse Ellen versus the size of the Unisphere next slide I’m not going to spend too much time here but this enables a an exciting side-by-side snapshot of the effects in the Kiwi sheath on the Left compared to the effects and the interstellar medium on the right I’ll quickly point out that even though the cosmic ray profiles on the top a and D are very similar the effect of Ward 2 2 was seen from all directions in the sky well voyager 1 it was only isolated to that specific region I just described centered at 90 degrees why is this we do not know next slide finally the interstellar boundary Explorer ibex which remotely images the heliosphere is global boundaries recently observed the effects of the substantial increase in the sun’s output yeah and the step up in the bottom plot in red around May 2014 and that a substantial increase way to pressurized the heliosheath and you can see that captured in the the top right sphere in that red region and this continues to inflate various regions in the hue to this day so we have a global observations that show the effect what to the goiters see next slide that particular event was the largest of these pressure pulses in the Huey sheath seen by Voyager 2 and it was later seen as a very strange magnetic disturbance

unlike the prior shocks at Voyager 1 so the magnetic field had a 35 day ryan’s time and then 340 dating kind of gradual change and we’ve never seen anything like this before next slide so we live in a very exciting time where there’s a lot of activity and a lot of open questions about what’s happening in the interstellar medium and there’s a whole selection of these they’re just here for reference but next slide regarding what I’ve discussed today I think some key ones are how far into the interstellar medium can these transients be observed and why are there anisotropies that are beyond the heliopause but not in the human sphere itself and why did cosmic ray electrons behave so differently than the protons out there and what new things what new things can we learn about the fundamental physics in the interstellar medium and this opens a whole lot of opportunity for exciting science on interstellar probe next slide and this is just kind of an overall list with some details but I think some of the most exciting things are the opportunity to monitor space weather not just close to Earth but beyond the entire Gila pause and it’s an opportunity to also connect to the broader human physics fleet and we can provide Institute context for global observations there’s a new mission that will map the outer boundaries called interstellar mapping and acceleration probe due to launch in 2024 and it’s important to have both the combination of these global observations and the Institute measurement and we can also watch the heliosphere evolve just under very different solar cycle conditions and we can uncover yet to be understood properties of the heliosheath in the interstellar medium thank you very much all right thank you very much Jamie Muro and Elena for your wonderful presentations we’re not going to go to the question and answer session so we have a few questions that merav you had answered and I’d like to discuss those with everyone here so the first question was does a trajectory through the flanks aid the modeling sufficiently through the nose or does it offer more interesting region for dynamics as posed by the models Morocco I wonder if you could address that hey thank you James so I think why I advocated for going so the flanks is because Voyager 1 and 2 left the heliosphere very close to the nose Voyager 1 exactly the nose and Voyager 2 30 degrees but still very much within the nose the flanks are will need to go much more at 16 degrees or more so that the region is interesting for many reasons one of them we think by several models are the originals and no one else cosmic rays whether it’s coming at the heliopause or whether it’s coming near the termination shock it’s coming from the flanks we can see some new measurements that show that they’re streaming toward the spacecraft from the flanks so this would be one reason to really probe in situ much closer the origin of the numerous cosmic rays the other one is that them if you really want to study the shape of the heliosphere if it goes to the nose you can look back you can see the shape so if you’ve got on the flanks you can have energetic neutral atoms detector there or even just understanding the plasma behavior and the draping of the magnetic field will allow you to constrain again with in situ measurements what is the shape of the heliosphere and you know lastly there is also the question about how the magnetic field from the galaxy drape around the heliosphere and we think that this is changing to a solar light direction from some effects and phenomena happening on the flanks so again we would be able to pull by going to that region thank you very much merabh and then could you comment on the second which was how much of the galactic cosmic rays are shielded by the heliosphere and how much by Earth’s magnetic fields and hence how important is the heliosphere really for the burdens of evolution of life so right so as I showed in my plot I think with the second slide with the galactic cosmic rays varying the intensity with the solar cycle there are some peaks and valleys as voyager went but the major jump for the 75% shield happened after the termination shock in the last layer on the heliosheath so it’s mean that the

atmosphere was a heliosphere the gila shit is a crucial filter for the galactic cosmic rays something does happen within the heliosphere and further by the magnetic field of Earth but the main shielding that 75% happen at the heliosheath the last layers thank you very much for us and then Jamie a couple questions for you so the first one by Stephen Talbot how does the interstellar probe require a certain specific set of measurements continuing by a future heliophysics fleet well my statement was mostly saying that there’s an opportunity a very exciting opportunity that when interstellar probe gets out there there is a fleet that’s constantly observing the Sun and so if we see an event like this pass we can you know when it arrives at different places with whatever fleet is out there and then eventually track that out there at interstellar probe okay thank you and then for the next question by Christopher Rose for you Jaime as well do we have any sense of how neutrino density or behavior might change from the heliosphere to the interstellar medium no we don’t have any neutrino detectors you’d be anything to do but I don’t know that any have been flown okay all right thank you and now we have another question well if and this is for you Jamie Oh will it be possible to differentiate and the particles related to the Cir s from that of this transients using interstellar probe observations outside the heliosphere that’s an excellent question the event the last event that I showed that was seen in ibex was an example of something that’s not just a Cir so that event did show unusual signatures at Voyager compared to these other transients which are emerging of multiple Cir so possibly by studying that event a lot more closely which is ongoing we’ll be able to tell the key variables that discriminate just these passing ones from cool changes to the saw output however it’s important I think to have some sort of mapping mobile mapping picture because that’s the easiest way to to be able to tell the difference I can just add one thing to what Jaime is saying that in terms of modeling and theory and Elena is an expert on that as well we don’t really understand the evolution of Siri ours and neither sharks all the way from the Sun to the interstellar medium we have some idea how they merge and evolve but we don’t have it you know really understood that we can really pop one by one which shock generated with signatures is M thank you very much – yeah if I can maybe add James to this as this structures propagate through the interface through determination shock and heliopause interaction of CIA ours and associated shocks and Cimiez or global North interaction regions with their shocks as they go through the interface they generate more structures and it’s it’s it’s really you know difficult to extract the original structures and those that are newly generated thank you very much Elena I’m looking at the question answer now I don’t see any new questions so I’ll wait a couple of seconds alright um so thank you very much that’s all the time we have for today so first I’d like to thank all of our panelists and at length and I’d like to thank you for attending today’s webinar our next webinar will be on Thursday June 25th at noon Eastern Time titled imaging the heliosphere at boundary where we will have a panel presentation by pontus brandt kostas dl eNOS and Eric cameras please visit the inner solar probe website for more information about the study and to view information on future webinars and events also please consider signing up for our listserv using the community involvement section of the website to make sure you’re getting you are getting the latest information on upcoming webinars and events thanks for joining us and have a wonderful day