ISRO has done the Nation proud by launching the ‘Aditya-L1’ satellite that will study comprehensively ‘Aditya’ or the Sun. That it has 7 distinct payloads, to study ‘Aditya’ all developed indigenously, speaks of the great perseverance and commitment of our scientists. The ‘Aditya Mantra’ ‘Om Bhur Bhuvaḥ Swaḥ Tat Savitur Vareṇyaṁ Bhargo Devasya Dhiimahi Dhiyo Yo Naḥ Prachodayaat’ is often recited by every Hindu with devotion and reverence to connect with the Sun god’s radiant energy and seek blessings for clarity of thought and inner illumination. It is an invocation of the divine light of the Sun. It inspires wisdom, enlightenment, and spiritual awakening. Reaching out to it, in order to understand its mysteries, is like reaching out to God. So here we go on ‘Aditya-yan’.
The Sun, like other stars, is a massive celestial object, primarily, composed of hydrogen and helium constantly under nuclear fusion in its core. While fusion is the process of combining two light atomic nuclei to form a heavier nucleus, releasing tremendous amount of energy in the process, nuclear fission is the process of splitting a heavy atomic nucleus into two or more lighter nuclei, also releasing substantial amount of energy. Whereas, on the Sun, hydrogen nuclei or protons fuse together to form helium through a series of nuclear reactions, we on the earth, simulate nuclear fission in our nuclear reactors to produce energy to support life. It is another matter that we also use the same energy for destruction in the form of atomic bombs. Further, whereas fusion has the potential to provide a virtually limitless and clean source of energy on Earth, and does not produce long-lived radioactive waste, fission produces radioactive waste, which has to be carefully managed and stored for long periods to prevent environmental contamination and health risks. In short, ‘Aditya’ produces ‘clean energy’ whereas we produce ‘dirty energy’.
There are many fascinating aspects and scientific knowledge about the Sun that have been discovered over the years. The Sun’s core is extremely hot and dense, with temperatures reaching millions of degrees Celsius. Sun is an incredibly powerful energy source radiating energy in the form of sunlight, which provides heat and light to our solar system. Can anyone imagine how much will this energy be? It is about 386 billion megawatts, equivalent to the energy from about 100 billion nuclear bombs exploding every second.
Through the ages, the scientists have found the Sun consisting of several layers, including the core, radiative zone, convective zone, photosphere, chromosphere, and corona. Each layer has different temperatures and properties. The Sun emits a constant stream of charged particles, primarily electrons and protons, into space, known as the solar wind, and it can affect the Earth’s magnetic field and space weather. One of the pay-load on ‘Aditya-L1’ will study this aspect.
Sunspots, cooler regions on the Sun’s surface caused by magnetic activity are dark and vary in size and number over a 11-year solar cycle. Similarly, Solar flares are intense bursts of energy and radiation that occur when magnetic energy stored in the Sun’s atmosphere is suddenly released. These flares can have a significant impact on satellite communications and Earth’s ionosphere. More of our satellite’s payloads will study these aspects. Solar eclipses occur when the Moon passes between the Earth and the Sun, blocking out the Sun’s light. They offer scientists valuable opportunities to study the Sun’s outer atmosphere, called the corona, another subject for our satellite’s pay-load.
It is the Sun’s gravitational pull that played a central role in the formation of our solar system. Planets, moons, asteroids, and comets all formed from the same spinning disk of gas and dust that surrounded the Sun.
The Sun is approximately 4.6 billion years old and is expected to continue its fusion processes for several billion more years. Eventually, it will exhaust its hydrogen fuel and transition into a red giant before ultimately shedding its outer layers and becoming a white dwarf. Understanding the Sun and its properties is essential for a wide range of scientific disciplines, including astrophysics, solar physics, and space weather forecasting. ISRO Scientists will continue to study the Sun to unlock more of its mysteries and improve our understanding of its impact on our planet and the broader universe for, ‘Aadityaaya vidmahe divaakaraaya dhiimahi. Tanno aadityaḥ pracodayaat’. Invoke the Sun God’s blessing with enlightenment, wisdom, and guidance.