India's Aditya-L1 solar mission has completed a successful first year of observations with its Solar Ultraviolet Imaging Telescope, known as SUIT, giving scientists a closer look at the Sun's lower atmosphere and its explosive activity. A research paper describing the instrument's performance explains how it was operated, calibrated and maintained while it captured important features of the Sun, including solar flares. The paper is titled "Unraveling the Secrets of the Lower Solar Atmosphere: One Year of Operation of the Solar Ultraviolet Imaging Telescope (SUIT) on board Aditya-L1". It was led by Rahul Gopalakrishnan and a team of researchers, and it has been accepted for publication in the Journal of Astrophysics and Astronomy. Aditya-L1 was launched by the Indian Space Research Organisation on September 2, 2023. It is India's first dedicated space-based solar observatory. The spacecraft reached its halo orbit around the Sun-Earth Lagrange Point 1, called L1, on January 6, 2024, about 1.5 million kilometres from Earth. From there it gets a largely uninterrupted view of the Sun, without the regular breaks caused by Earth's shadow or eclipses.
What SUIT sees
SUIT is one of seven scientific instruments carried by Aditya-L1. It captures images of the Sun in near-ultraviolet light, covering wavelengths between 200 and 400 nanometres. The instrument was switched on November 20, 2023, and it captured its first scientific images on December 6, while the spacecraft was still travelling towards L1. Unlike observations made using visible light, SUIT's ultraviolet images let scientists examine features in the Sun's photosphere and chromosphere, two layers of its atmosphere that hold important clues about solar activity.
A year of flares and eruptions
The research paper records the instrument's calibration, regular maintenance, operating procedures and observations during its first year. It also highlights notable solar features and events recorded in that period. Among them was an offlimb eruption followed by a flare arcade on February 16, 2026, captured in the magnesium II k line at 279.6 nanometres, and full-disk solar observations made on October 24, 2026. The mission aims to help scientists understand how the Sun's outer atmosphere gets heated, how solar flares and massive eruptions of material begin, and how these activities influence space weather. That matters because space weather can affect satellites, communication networks and power systems on Earth.
Why the lower atmosphere matters
Understanding activity in the Sun's lower atmosphere is important because it can help scientists trace how solar disturbances develop and grow into larger eruptions. Such observations can improve our understanding of space weather and the possible impact of solar activity on technology around Earth. With a planned mission life of five years, Aditya-L1 will keep collecting observations through its seven instruments, helping scientists build a more complete picture of the Sun and its influence on Earth's space environment.
