Lagrange points are minor equilibrium points under the influence of two big masses. It’s like a parking lot for space masses to easily and effortlessly float in the space. Satellites and spacecraft would require significantly less energy to be stable in a Lagrange Point than the satellites, which are openly going into the fabric of space. The only confusion with Lagrange Points is how they occur and their mechanics?
Lagrange points became a hot topic when NASA sent the James Webb Telescope to the L2 point. But the Lagrange Points were discovered way back in 1772 by a French mathematician Joseph Louis Lagrange. Astronomers discovered real-life examples of Lagrange Points in 1906. For the first time, astronomers discovered Trojan asteroids moving under the influence of Jupiter and the Sun. In the modern-day, with all the technologies, still, we are confused about these points and their mechanics. We have only used L1 and L2 points, but think about the French Mathematician Joseph Lagrange who discovered the Lagrange Points in 1772; with such limited resources and technologies, Joseph Lagrange deserves tremendous respect from modern-day astronomers.
What Are Lagrange Points?
Lagrange Points are positions/places in the space where an object tends to stay without any extra effort or energy requirements. When two large mass objects precisely equal the centripetal force, it creates a unique place for small objects to stay without the required energy to balance themselves, these points are called the Lagrange point.
How many Lagrange Points Do We Have?
We have five Lagrange points between the two large masses, The Earth and the Sun. These five points are unique because of the Earth and Sun’s gravitational force, which creates a special place where the centripetal force becomes equal. These five Lagrange points are:
The L1 Point
The L1 is the most known and most used Lagrange point of all. It lies 1.5 million kilometers inside the Earth’s orbit and occurs because of Earth and Sun’s gravitational forces.
The Solar and Heliospheric Observatory (SOHO), The Advanced Composition Explorer (ACE), WIND (At L1 since 2004), The Deep Space Climate Observatory (DSCOVR), and The ESA/NASA solar watchdog spacecraft are still operating in the L1 section of the space.
The L1 point is perhaps the most crucial section for spacecraft to study and explore the solar system. It has its unique benefits, and most importantly, it is the nearest Lagrange point to us.
The L2 Point
The L2 point is where NASA recently parked the James Webb Telescope. The L2 point is ideal for astronomers to study deep space because it is far from the sun and behind the earth, almost a million miles away from us. The place is primarily cold and in deep space, making it a perfect spot for space telescopes like James Webb. The temperature in deep space, especially in the L2 section, is around -230 degrees Celsius.
Currently, the L2 section is the home of The ESA Gaia probe, the joint Russian-German high-energy astrophysics observatory Spektr-RG, and the joint NASA, ESA, and CSA James Webb Space Telescope (JWST).
The L1 and L2 are the unstable Lagrange Points. After every 23 days, the spacecraft needs to correct its altitudes manually.
The L3 Point
The L3 point is the untouched point. We have not found any use for the L3 point yet. It’s the farthest Lagrange point and is located behind the sun, making it challenging to explore.
The L4 and L5 Points
The L4 and L5 points are the most stable Lagrange points. Spacecrafts in L4 or L5 don’t need altitude correction if the mass is less than 24.96. Due to the perfect natural stability, the L4 and L5 are home to many natural objects, such as Trojan Asteroids. But there are multiple spacecraft that are orbiting these points too.
L4 Space Missions
STEREO A (Solar TErrestrial RElations Observatory – Ahead) made its closest pass to L4 in September 2009, on its orbit around the Sun, slightly faster than Earth, OSIRIS-REx passed near the L4 point and performed a survey for asteroids between 9 and 20 February 2017.
L5 Space Missions
The Spitzer Space Telescope is in an Earth-trailing heliocentric orbit drifting away c. 0.1 AU per year. In c. 2013–15 it has passed L5 in its orbit, Hayabusa2 passed near L5 during the spring of 2017 and imaged the surrounding area to search for Earth trojans on 18 April 2018.
The Lagrange Points are magnificent because it makes space exploration possible. The name Lagrange or L1,2,3,4,5 honors the Franch Mathematician Joseph Louis Lagrange who discovered the Lagrange points in 1772. Some of the media, formulas, and links are taken from educational sites such as Wikipedia. The article’s purpose was to spread educational awareness about the Lagrange Points to the everyday reader. If you want to study the Lagrange points deeply, we recommend you go through Wikipedia’s resources.
GMISR-Space (Educational Awareness For Curios Minds)