Introduction

India’s pioneering solar mission, Aditya-L1, has achieved a significant milestone as advanced sensors onboard successfully detected the impact of coronal mass ejections (CMEs), marking a leap forward in space exploration.

Coronal Mass Ejections (CMEs)

CMEs were discovered in 1971 and established their importance in solar-terrestrial relations later in the 1980s.
It consists of massive clouds of solar plasma and magnetic field lines.
It typically accompanies solar flares and filament eruptions.
The frequency of CMEs varies with the 11-year solar cycle, with about one a week observed during solar minimum and an average of two to three CMEs per day observed near solar maximum
They travel at thousands of km per hour.
They can lead to geomagnetic storms, aurorae, and in extreme cases, damage to electrical power grids.
They are primarily detected using coronagraphs aboard spacecraft such as SOHO and STEREO.
Not all CMEs interact with Earth, but those that do can cause disruptions to satellite communications and power grids.
Halo CMEs are Earth-directed CMEs visible as rings in white-light coronagraph observations.

Purpose: PAPA is an energy and mass analyser tailored for in-situ measurements of solar wind electrons and ions within the low energy range.
Sensor Composition: PAPA comprises two sensors—Solar Wind Electron Energy Probe (SWEEP) and Solar Wind Ion Composition Analyser (SWICAR)—facilitating comprehensive observations of solar phenomena.
Functionalities: Sensors not only measure electrons and ions’ energy but also ascertain their direction of arrival, enabling a holistic understanding of solar wind dynamics.

Observations: PAPA detected CME events, notably on December 15, 2023, and during February 10-11, 2024.
December 15, 2023: Single CME event marked by a sudden increase in electron and ion counts, aligning with solar wind parameters and magnetic field measurements.
February 10-11, 2024: Multiple minor CME events observed, showcasing nuanced variations in electron and ion counts over time.

PAPA sensors are currently operational in default mode, demonstrating adherence to design specifications across all operational modes.
Continuous observations underscore PAPA’s efficacy in monitoring space weather conditions and its adeptness in detecting and analyzing solar phenomena.

Launched successfully by ISRO on September 2.
Orbits around the Lagrangian Point 1 (L1), maintaining a stable position 1.5 million km from Earth in the direction of the Sun.
Hosts seven payloads dedicated to studying various aspects of the Sun, encompassing both remote observations and in-situ measurements.