NASA selects Sydney expert to study the Sun and space weather

Iver Cairns, Professor in Space Physics and Director of the ARC Training Centre CUAVA at the University of Sydney, is the only international co-investigator to be selected for both critical missions.

These missions will do fundamental, world-leading science on the causes of space weather, which impacts our daily lives.

Space weather

The Sun generates a vast outpouring of solar particles known as the solar wind, whose variability creates space weather. Near Earth, where such particles interact with our planet’s magnetic field, space weather can lead to profound impacts on human interests, such as astronauts’ safety, radio communications, GPS signals, and utility grids on the ground.

The more we understand what drives space weather and its interaction with the Earth and lunar systems, the more we can mitigate its effects – including safeguarding people and technology on Earth and in space.

“These missions will do big science,” said Thomas Zurbuchen, Associate Administrator for the Science Mission Directorate at NASA Headquarters in Washington, in a NASA statement.

“But they’re also special because they come in small packages, which means that we can launch them together and get more research for the price of a single launch.”

NASA small satellite missions

The NASA Small Explorer (SMEX) missions are designed to further our understanding of the Sun and its dynamic effects on space. The selected mission PUNCH (Polarimeter to Unify the Corona and Heliosphere) will study how the Sun drives particles and energy into the solar system while the TRACERS (Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites) mission will study Earth’s response.

Professor Cairns, from the School of Physics, has been selected to work on the two missions:

1)    The PUNCH mission will focus directly on the Sun’s outer atmosphere, the corona, and how it generates the solar wind. Composed of four suitcase-sized satellites, PUNCH will image and track the solar wind as it leaves the Sun. The spacecraft also will track coronal mass ejections – large eruptions of solar material that can drive large space weather events near Earth – to better understand their evolution and develop new techniques for predicting such eruptions.

Professor Cairns will perform advanced computer simulations and comparisons with PUNCH data to understand coronal mass ejections, large eruptions of solar material that can drive large space weather events near Earth. He will also study the generation of radio emissions and the fall-off of the plasma's density between the Sun and Earth. 

2)    The second mission, TRACERS, will observe particles and fields at the Earth’s magnetic cusps – the regions above Earth’s poles, where our planet’s magnetic field lines curve down toward Earth. TRACERS will study how magnetic fields around Earth interact with those from the Sun. 

Professor Cairns will study the timing and properties of energetic particles and plasma waves observed by TRACERS to determine how magnetic reconnection occurs and accelerates energetic particles. He will also develop detailed theories for how the plasma waves are produced and evolve.  

Australian CubeSat missions

“PUNCH and TRACERS address some of the biggest open questions in space science and astrophysics,” said Professor Cairns.

“PUNCH’s four small satellites will allow us to measure and understand how the Sun’s magnetic field loops and million-degree plasma are transformed into the turbulent solar wind, which streams past and interacts with the Earth and other planets.

"TRACERS’s two satellites will explore how magnetic reconnection proceeds at Earth and accelerates energetic electrons and ions through the cusps into the atmosphere and ionosphere.

“Although built in the USA, the six new satellites for PUNCH and TRACERS will provide great case studies for students, postdoctoral researchers, scientists, and industry people involved in the Australian Research Council’s training centre CUAVA.

“Our participation in these missions will benefit the five CubeSat missions that CUAVA anticipates flying in the next five years.”

Launch date for the two missions is no later than August 2022.

Funding Declaration: NASA is supporting the PUNCH and TRACERS missions with total funding of US $280 million.  

Featured image: A constant outflow of solar material streams out from the Sun depicted in an artist's rendering. Credit: NASA.