How do weak shocks accelerate high energy particles?

Lead Research Organisation: University College London
Department Name: Mullard Space Science Laboratory

Abstract

Shock waves are found everywhere in the Universe and are one of the most efficient ways of accelerating particles like protons and electrons. However, the conditions required to produce those shocks and accelerate particles are so extreme that they're impossible to recreate on Earth. As a result, we still don't know a lot about how these shocks accelerate particles or how they're affected by things like density or magnetic field. Most of the shocks that produce these very high energy particles are also incredibly far away in other galaxies, making them difficult to study properly. For example, while we can see a supernova shock using astronomical telescopes, it's really hard to then identify and study the particles it accelerates.

However, the Earth is located close to a natural laboratory with extreme density, temperature and magnetic field variations which regularly produces large-scale shocks that shower us with energetic particles; the Sun. We have a fleet of spacecraft returning constant observations of the Sun, allowing us to see in near-real-time the sudden release of stored magnetic energy in the solar atmosphere (also called the corona). This energy release can produce bursts of radiation that we call solar flares, hurl massive bubbles of plasma called coronal mass ejections into the solar system towards the Earth and launch vast global shock waves that can travel across the Sun in under an hour. Although these shocks are so much weaker than supernovae that they shouldn't be able to accelerate any particles, they regularly produce billions of energetic particles that we can almost immediately detect at Earth. These particles can be fatal for satellites orbiting the Earth, blinding them and causing them to fail, with knock-on effects for GPS and telecommunications. With my research, I'm trying to understand why these really weak shocks occur, how they accelerate particles to incredibly high energies and how those energetic particles affect the Earth and the near-Earth environment.

The Sun offers a unique opportunity to study both extreme shocks and the particles that they accelerate at the same time in unprecedented detail; we can see what happens and "touch" the resulting particles, which is something that you can't do in any other field of astrophysics. Everything about this situation is also very counterintuitive; the Sun is a pretty average star producing very weak shocks that shouldn't be able to accelerate any particles yet it manages to accelerate particles to incredibly high energies. How this happens is still an open question, and one that has implications not just for our understanding of the Sun, but also for fundamental plasma physics and space weather. If we know how this process works we might be able to predict it, which will help us to protect vulnerable spacecraft and infrastructure on Earth. On a more personal level though, working on this topic really hammers home the differences between how calm the Sun is when you look at it from the ground versus the violently active Sun producing solar eruptions which we see from space, which I just think is fascinating.
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation Academy of Athens
Country Greece 
Sector Academic/University 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation Austrian Academy of Sciences
Department Space Research Institute
Country Austria 
Sector Academic/University 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation Boston University
Country United States 
Sector Academic/University 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation Centro Universitario de Ciudad Juárez
Country Mexico 
Sector Academic/University 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation Imperial College London
Country United Kingdom 
Sector Academic/University 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation International Space Science Institute (ISSI)
Country Switzerland 
Sector Academic/University 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation National Aeronautics and Space Administration (NASA)
Department Goddard Space Flight Center
Country United States 
Sector Public 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation Queen Mary University of London
Department Queen Mary Innovation
Country United Kingdom 
Sector Private 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation Royal Institute of Technology
Country Sweden 
Sector Academic/University 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation University of Buenos Aires
Country Argentina 
Sector Academic/University 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Team at the International Space Science Institute on "Foreshocks Across the Heliosphere: System Specific or Universal Physical Processes?" 
Organisation University of California, Los Angeles (UCLA)
Country United States 
Sector Academic/University 
PI Contribution This is an international team convening at ISSI to study shocks throughout the heliosphere and quantify if the processes associated with them are universal or system specific. Each member of the team is an expert in studying shocks in different locations throughout the heliosphere. As an expert in shocks in the solar corona, I am the solar physics representative.
Collaborator Contribution Each member of the team is an expert in shocks in a different region of the heliosphere and the aim of this team is to try and quantify whether the processes associated with the different shocks are system specific or universal.
Impact The collaboration was originated in 2018 with the aim of applying to ISSI as an international Team. The first application was unsuccessful, but the feedback was vital to improving the application. The improved application was submitted to the 2019 call where it was successful. Although we have been working on preparation for the meeting since June 2019, the first official meeting was the first week of March 2020. As a result, there are no significant outcomes yet. At the meeting there was a lot of discussion about the different systems and phenomena and a roadmap was developed for the papers to be written by the group. The aim now is to work on these papers and try to submit them within the next year.
Start Year 2018
 
Description Interview for UK Space Agency talking about the launch of Solar Orbiter 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was interviewed by the UK Space Agency for a short video released via their social media presence discussing the launch of the ESA Solar Orbiter spacecraft. The video was aimed at the general public and was retweeted 49 times.
Year(s) Of Engagement Activity 2020
URL https://twitter.com/spacegovuk/status/122610050488072192