MISSION SUN ｜India’s first Solar Mission Aditya-L1 to Unravel the Mysteries of the Sun

After the moon, this time IRSO targets the sun. After two consecutive lunar missions, the Indian Space Research Organization (ISRO) is now targeting the sun. It may not be possible to reach the Sun's ring of fire, but many attempts will be made to reach the Sun. So that our nearest star Sun can be studied sitting at the tip of the nose. India's first solar spacecraft 'Aditya L-1' is going to cross the earth towards the sun for that purpose. If the mystery of the sun is possible to reveal, new horizons will be opened not only in solar physics but also in other branches of science.

Scientists have done a lot of research on the sun, but it is very important to travel to the sun for more perfect and complete research. Aditya L-1 will do that. The Sanskrit word Aditya means sun. The spacecraft planned to be launched from the Satish Dhawan Space Center in Sriharikota, Andhra Pradesh in early 2020 with the help of Polar Satellite Launch Vehicle-XL or PSLV-XL rocket. But the COVID-19 global pandemic in this early 2020 changes every plan and satellite launching program. The spacecraft, built entirely on indigenous technology, was assisted by ISRO at the Indian Institute of Astrophysics (IIA) in Bangalore, the Inter-University Center for Astronomy and Astrophysics (IUCAA) in Pune, the Institute of Physical Research in Ahmedabad, Udaipur Solar Observatory in Rajasthan, Rajasthan and Space Physics Laboratory in Thiruvananthapuram.

Satish Dhawan Space Center in Sriharikota, Andhra Pradesh (Image: DNA India)

At first, it was thought that the corona or solar corona of the sun would be tested with Aditya L-1K. Because of its heavyweight (400 kilograms) and thus, it was planned to be placed 600 km in a low orbit of the earth. Later that plan changed and Aditya-1 was converted to Aditya L-1. Aditya L-1 will observe the sun continuously for at least five years without any eclipse or obstruction at a distance of 1.5 million kilometers from the earth and 1,481 million kilometers from the sun. About 100 days after launch, the satellite will begin orbiting L-1 in hello orbit. In this way, by secretly monitoring the Sun, it will send pictures of all the activities of the Sun to this blue planet. The satellite will have a total of seven pay-load or experimental state-of-the-art scientific instruments. Scientists believe that this state-of-the-art satellite weighing 1,500 grams, including fuel, will be able to unravel the mystery of the solar corona.

But, why is the solar corona so mysterious? There is a nuclear reactor in the center of the sun. There, hydrogen is constantly converted into helium in the process of nuclear-bonding. The amount of mass that is ‘lost’ during this transformation is converted into heat energy and light energy. This whole process follows Einstein's formula E = mc². As a result, the temperature at the center of the sun is about 1.5 million Kelvin. The temperature of the sun's surface or photosphere is 5 thousand Kelvin. That is, the temperature decreases as it moves from the center of the sun to the surface of the sun. But the temperature of the solar corona, which is more than ten times the distance from the photosphere, is about 1 million Kelvin. This means that the temperature of the corona, which is farther away than the photosphere near the center of the sun, is about 200 times higher. Again the temperature of the corona is not the same everywhere. 

India’s first solar mission Aditya-L1 to unravel the mysteries of the Sun (Image: Current Hunt)

Aditya L-1 will find out why the temperature of the corona is so high, or why there is so much difference in the temperature of different parts of the corona. In addition to the corona, the spacecraft will monitor the photosphere and chromosphere. The photosphere is one of the lowest layers of the sun. The light that we see on Earth is emitted from this photosphere. This light from the sun reaches our earth after 8 minutes and 20 seconds. The second level is the chromosphere. The moon covers the photosphere during a total solar eclipse. We then see the pink-red chromosome and the corona.

Sun is also made up of several layers, each of which serves its own purpose (Image: Universe Today)

On August 12, 2017, NASA sent the world's first solar spacecraft 'Parker Solar Probe' into space. It has already successfully orbited the Sun twice from a very close distance (only 6 million kilometers from the Sun). This spacecraft has already sent a lot of important information. These are expected to help Aditya L-1 a lot. Aditya L-1 will be able to unravel the secrets of the sun that we see in the sky every morning to evening, for which only water is in liquid form on this earth, life has been transmitted to the earth. That is the idea of ​​ISRO scientists.

After NASA and the European Space Agency, India is the first to cross the solar system. If this mission is successful, India's place in the history of space science will not only be strengthened, but many long-standing questions of physics will also be solved.