LAGRANGIAN POINTS
- SCI & TECH
News: ISRO’s Aditya-L1
successfully placed in a halo orbit around L1 point
What's in the
news?
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The Indian Space Research Organisation
(ISRO) has placed the Aditya-L1 spacecraft in a halo orbit around the
Lagrangian point (L1).
Key takeaways:
●
India’s maiden solar mission Aditya-L1 reached the L1 point on January 6, 127 days after it was
launched on September 2, 2023.
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The point is located roughly 1.5 million
km from earth and enables the spacecraft to view the sun continuously.
Lagrangian Point:
●
These are specific locations in space
where the gravitational forces of two
large bodies, such as the Earth and the Moon or the Earth and the Sun, balance
the centrifugal force experienced by a smaller object, such as a satellite.
5 Lagrangian
Points:
●
There are five Lagrangian points, labelled L1 to L5, in the
three-dimensional space surrounding two large bodies in orbit around each
other.
○
L1, L2, and L3 are
located on a line that connects the two
large bodies and are unstable equilibrium points, meaning an object placed
there will not stay in that position without continuous propulsion.
○
L4 and L5, on
the other hand, are located at the third
corners of a tetrahedron formed by the two large bodies and their barycenter,
and are stable equilibrium points, meaning an object placed there will
remain in that position without propulsion.
L1 Point:
●
The
L1 point of the Earth-Sun system
affords an uninterrupted view of the sun and is currently home to the Solar and Heliospheric Observatory Satellite (SOHO).
L2 Point:
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The L2 point in the Earth-Sun system is a strategic location for spacecraft like WMAP, Planck, and the James Webb Space
Telescope.
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It offers advantages for astronomy, as it
allows for easy communication with Earth, provides uninterrupted solar power,
and offers a clear view of deep space.
Other Key
Features:
●
The L1 and L2 points are unstable on a time scale of
approximately 23 days, which requires satellites orbiting
these positions to undergo regular course and attitude corrections.
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Stable orbits at L4 and L5 Lagrange points require a mass
ratio greater than 24.96, seen in
Earth-Sun and Earth-Moon systems, as well as elsewhere in the solar system.
●
Objects found orbiting at the L4 and L5 points are often called Trojans after the three large asteroids
Agamemnon, Achilles and Hector that orbit in the L4 and L5 points of the
Jupiter-Sun system.