India achieved a significant milestone in its solar exploration efforts with the successful launch of Aditya L1, part of its solar mission, from Sriharikota on Saturday.
In approximately four months, Aditya L1 will reach its designated Halo orbit, L1, situated in close proximity to the Sun. At this point, its array of seven scientific payloads will activate, aiming to unravel some of the Sun’s most intriguing mysteries.
One of these mysteries revolves around the extraordinary high temperature of the Sun’s corona, the outermost layer of the Sun’s atmosphere, which is typically obscured by the Sun’s intense surface brightness.
Somak Raychaudhury, Vice-Chancellor and scientist at Ashoka University, elaborated on the primary objectives of this mission. “One of our primary goals is to understand why the Sun’s corona is astonishingly hot, reaching temperatures of up to 2 million degrees, in stark contrast to the relatively cooler surface of the Sun at around 5,000 degrees,” he explained in an interview with Hindustan Times.
Raychaudhury emphasized how the Solar mission will enhance India’s capacity to continuously monitor the Sun around the clock, which is unfeasible from Earth’s orbit due to frequent planetary obstructions.
The central thrust of the mission is to enable uninterrupted, 24-hour observation of the Sun, facilitating comprehensive tracking of its activities. Aditya L1 boasts two principal instruments, complemented by five smaller ones.
The SUIT (Ultraviolet Imaging Telescope) serves as an ultraviolet imager capturing continuous images of the Sun. The ultraviolet spectrum plays a crucial role in solar observations due to the significant ultraviolet and X-ray radiation emitted by the Sun’s corona.
Another pivotal instrument, VELC, is a spectrograph tailored to scrutinize the Sun’s corona, the outermost layer of the Sun’s atmosphere that extends far beyond its visible disk. VELC will work in tandem with SUIT, allowing ISRO scientists to correlate corona changes with surface events.
Delving into the puzzling phenomenon of the Sun’s corona’s high temperature, Raychaudhury emphasized its extreme nature, with temperatures soaring to 2 million degrees—a striking contrast to the Sun’s cooler surface at approximately 5,000 degrees. This temperature gap remains an enigmatic riddle in solar science, and studying high-energy phenomena of the Sun is crucial to unraveling it. Aditya L1 represents a pivotal asset for establishing causal links between the Sun and its corona.
The data collected by Aditya L1 will also play a vital role in bridging the gap between the Sun’s surface and the emission of high-energy particles during solar storms. Raychaudhury highlighted the close relationship between these storms and the Sun’s magnetic activity, underscoring the potential harm they pose to human technologies, including satellites and communication systems.