Aditya-L1 was launched by ISRO on September 2, 2023, to observe the Sun and help us understand it better. It reaches destination L1 or the first Sun-Earth Lagrangian point on January 6th.
Here's everything you need to know about the mission, from why it's important to why it's set in the L1 zone.
But why learn about the sun first?
The Sun generates energy through nuclear fusion within itself and radiates it from its outer core. The photosphere produces both visible and infrared light at 6,000 degrees Celsius, which is essential for life. Above is the chromosphere, and even higher is a million-degree Celsius hot corona.
Interestingly, the corona is much hotter than the sun’s inner layers — there must be an energy source providing this heat. However, the mechanisms are not yet fully understood. Furthermore, it also emits radiation and X-rays that would kill life on Earth, if there weren’t an atmosphere that absorbs the most damaging radiation and the sun continues to bombard particles charged with electrons ma — stream of solar wind. These energetic particles produce the spectacular auroras known as the Northern and Southern Lights, which are seen near the Earth’s Northern and Southern poles.
Sudden bursts of energetic particles from the sun and ejected into interplanetary space, known as solar flares and coronal mass ejections These directly affect space weather, satellite communication systems and other space-based technologies, and can for power outages at particularly high latitudes of the Earth can be very difficult to predict.
What will Aditya-l1 do?
Because Aditya-L1 is located outside the Earth’s atmosphere, its instruments are able to observe UV radiation from the corona, in the process better understanding its function Furthermore, it constantly monitors the solar atmosphere and corona for observations eruptions in the sun and study the properties of energetic particles in the solar wind.
What is the position L1 of the sun?
L1 represents the first Lagrangian point — there are five such points from L1 to L5, associated with another celestial body, in the case of the Sun these points theoretically related to the Earth and the Sun a Discovered in the 19th century by Swiss mathematician Leonard Euler, Italian and French mathematician Joseph Louis Lagrange, we are particularly concerned with points L1 and L2 here because of their relevance to space missions.
When a spacecraft orbits the earth, it is affected by the gravitational pull exerted by the planet on which it is located. However, it does not hit the Earth’s surface because the Earth’s gravitational pull is normally balanced by the gravitational force created by the spacecraft’s orbit around the Earth.
Earth's gravity weakens as it moves away from the planet. Eventually, there comes a point where the earth's gravitational pull is comparable to that of the sun. If the spacecraft goes farther, it can be pulled into orbit around the sun, or eventually crash, depending on its speed.
L1 is the sweet spot between the Earth and the Sun, where the gravity and gravity exerted by the two celestial bodies on the spacecraft cancel each other out and consequently comes to pass that once it is placed exactly at L1, the Sun would always be there without wasting money energy.
Does this mean that the sun is in a fixed position in space?
Unlike Figure 1 , L1 is located on the line connecting the Sun and Earth. Just as the earth rotates around the sun, L1 rotates around the sun, always staying in the same direction. Thus, instead of moving in one direction in space, the sun remains in the same position relative to the sun and the earth.
Why L1 ?
If the sun were orbited around the earth, the task would be much easier. But it would also mean that the Earth would obscure the sun's view of the sun for some time. While choosing the right cycle can reduce the duration of such eclipses, they can’t completely eliminate them. Because the sun is meant to act as an early warning system for solar radiation and coronal mass emissions, it’s important to see the sun unobstructed
When the sun is L1, it always has the earth on one side and the sun on the other. Thus, the spacecraft's instruments can be pointed at the sun for a completely unobstructed view. While building a spacecraft around L1 is complicated, the benefit of a constant, unobstructed view of the sun is well worth the effort, risk and expense.
Several space missions have already been closed around the L1 site, including LISA Pathfinder, and the Solar and Heliospheric Observatory (SOHO), also a NASA-European Space Agency collaboration project
And what is L2?
L1 is ideal for observing the Sun, but L2 is a very useful base for spacecraft observing the outer universe. As you can see in Figure 1, L2 is also on the path connecting the Sun and Earth, but on the opposite side of the Earth, about 1.5 million kilometers away
Thus, all of the spacecraft's instruments in a halo orbit around L2 can point away from Earth, giving you an unobstructed view of deep space. The James Webb Space Telescope (JWST), Gaia, and Euclid are some of the most important astronomical observations currently orbiting L2.
