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What is Lagrange point, where ISRO's Aditya-L1 will be positioned to study Sun?
Aditya-L1 spacecraft is designed to provide remote observations of the solar corona and in situ observations of the solar wind at Lagrange point 1.
ISRO chairman S Somanath on Saturday said that Aditya L-1, India's first space-based mission to study the Sun, has reached Sriharikota and is ready to be launched in the first week of September. Somanath said the final date of launch would be announced in two days. The spacecraft is planned to be placed in a halo orbit around the Lagrange point 1 (L1) of the Sun-Earth system, which is about 1.5 million km from the Earth. Putting Aditya-L1 in the halo orbit around the Lagrange point 1 would allow the satellite to continuously view the Sun without any occultation or eclipses.
"After the launch, it will take 125 days from the earth to reach Lagrange point 1 (L1). We have to wait till then," Somnath said.
The Aditya-L1 mission, aimed at studying the Sun from an orbit around the L1, would carry seven payloads to observe the photosphere, chromosphere and the outermost layers of the Sun, the corona, in different wavebands.
What is Lagrange point 1?
Lagrange Point 1, often abbreviated as L1, is one of the five Lagrange points in the Earth-Sun system where the gravitational forces of the two bodies balance the centrifugal force felt by a smaller object, allowing that object to effectively "hover" in a stable position relative to the two larger bodies.
In the case of the Earth-Sun system, Lagrange Point 1 (L1) is located between the Earth and the Sun, about 1.5 million kilometers (about 930,000 miles) away from Earth, in the direction of the Sun. This point is on the line connecting the two bodies and is situated in the Earth's orbital path around the Sun.
L1 is a particularly interesting point because any object placed there will remain relatively stable with respect to the Earth-Sun system. This stability arises from the way gravitational forces interact at this point, making it a prime location for various scientific observations and space missions. For example, the Solar and Heliospheric Observatory (SOHO) has been positioned near L1 to have a continuous view of the Sun or the cosmos without being affected by Earth's atmosphere or the day-night cycle.
Using the special vantage point L1, four payloads directly view the Sun and the remaining three payloads carry out in-situ studies of particles and fields at the L1, thus providing important scientific studies of the propagatory effect of solar dynamics in the interplanetary medium, reported PTI.
