NASA has selected Texas-based Southwest Research Institute to lead its PUNCH mission which will image the Sun. This is a landmark mission that will image regions beyond the Sun’s outer corona. Dipankar Banerjee, solar physicist from Indian Institute of Astrophysics is also a Co-Investigator of the PUNCH mission. PUNCH, which stands for “Polarimeter to Unify the Corona and Heliosphere,” is focused on understanding the transition of particles from the Sun’s outer corona to the solar wind that fills interplanetary space.
“The Sun and the solar wind are one interconnected system, but [these] have until recently been studied using entirely different technologies and scientific approaches,” explains Prof. Banerjee in an email to The Hindu.
Focus on polar regions
Commenting on his role as Co-Investigator in the PUNCH mission, Prof. Banerjee said, “I will be working to study how the solar wind is accelerated. I will focus on the polar regions of the Sun.” The team also plans to observe the Sun using joint observations from PUNCH and Indian mission Aditya, which is underway.
India is planning to send up its own satellite Aditya-L1, a mission to study the Sun’s corona, and Prof. Banerjee is the co-Chair of the Science Working Group. “We expect co-ordinated observations of Aditya and PUNCH in order to understand our space weather environment,” he says.
Constellation of satellites
PUNCH will consist of a ‘constellation’ of four suitcase-sized microsats that will orbit the Earth in formation and study how the corona, which is the atmosphere of the Sun, connects with the interplanetary medium. The mission is expected to be launched in 2022.
The mission will image and track the solar wind and also the coronal mass ejections – which are huge masses of plasma that get thrown out of the Sun’s atmosphere. The coronal mass ejections can affect and drive space weather events near the Earth.
Other probes
Other missions such as NASA’s Parker Solar Probe and the ESA-NASA joint project, Solar Orbiter, which is due to be launched in 2020, can study the structures of the Sun’s atmosphere. The PUNCH mission enhances these by tracking these structures in real time. Since the Sun’s corona is much fainter than its surface layers, it cannot be viewed by the instruments directly. So PUNCH will block out the light from the Sun to view its corona and the structures in it.
