<p>From <a href="http://www.astronomy.com/magazine/ask-astro/2013/10/lagrangian-points" rel="nofollow noreferrer">this source</a> I get: </p>

<blockquote>
  <p>The size of these islands varies. Each planet in the solar system has
  its own Lagrangian points. The islands of stability get bigger farther
  from the Sun and also for more massive planets. The ones associated
  with Earth are roughly 500,000 miles (800,000 kilometers) wide. The
  biggest zones (at least in the solar system) are Neptune’s; they are
  about 2 billion miles (3.2 billion km) across.</p>
</blockquote>

<p>L1, L2, and L3 are unstable. If a Sattelite ventures too far from the Lagrangian area it will fall towards the sun. As you can see from the image below. This image came from the source linked above.</p>

<p><a href="https://i.sstatic.net/LAEoR.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/LAEoR.jpg" alt="enter image description here"></a> </p>

CC BY-SA 4.0
2019-10-03T21:49:23.250Z
But L1 has a 800000 km diameter?
Ghost
CC BY-SA 4.0
2019-09-25T20:40:43.403Z
2019-09-25T20:40:43.403Z
Natsfan
<p>I'm not sure how much this will add, but the points are exactly that - just points.   Gravitational bodies are often reduced to points for the purpose of calculations, such as, centers of mass and barycenters are also points.   The Lagrange points are the same - mathematically calculated points based on the two objects in orbit around their mutual barycenter.   The article @jmh <a href="http://www.astronomy.com/magazine/ask-astro/2013/10/lagrangian-points" rel="nofollow noreferrer">posted says exactly that</a>.</p>

<p>The L4 and L5 gravitational saddles where objects can have long term stable orbits and they can be very large, elongated regions generally in the same orbit ahead of or behind the orbiting planet, thought the size depends on a variety of factors.   Jupiter's L4 and L5 saddle regions are enormous, for example.  Larger across than the Earth's orbit around the Sun.</p>

<p>The L1-L3 points are different because there's no gravitational saddle where objects can remain in stable orbit.   They still generate a region of low adjustment that I'm sure the size of those regions of low adjustment are pretty well understood by some at NASA.   Satellites or telescopes that are put in L1 or L2 orbits require adjustment, but considerably less adjustment than a region in empty space away from a Lagrange point.  They also remain in the same position relative to Earth, which has advantages.</p>

<p>The satellite region around L1/L2 that NASA uses could be defined as a kind of area of influence, but there's no exact measurement for where it ends as it gradually tapers off.  Image below is not to scale.</p>

<p><a href="https://i.sstatic.net/wD2zc.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/wD2zc.jpg" alt="enter image description here"></a></p>

<p><a href="https://jwst.nasa.gov/content/about/orbit.html" rel="nofollow noreferrer">Source</a></p>

<p>The size also varies depending on which Lagrange point you're discussing.   To my knowledge, we've only parked objects in the Earth-Sun L1 and L2 points.   Moon-Earth Lagrange points have been discussed as parking spots for satellites, but never used to my knowledge.</p>

CC BY-SA 4.0
2019-09-25T23:14:49.980Z
2019-09-25T23:14:49.980Z
userLTK
<p>Like in cubic kilometers, what is the size of L1 "area of influence"? being unstable I guess that size can vary?</p>

CC BY-SA 4.0
2019-09-25T06:09:01.010Z
No matter how you define the degree of relative stability at $L_1$, you would naturally expect the volume of that region to depend on the masses of the two bodies and the distance between them. Which two-body system did you have in mind? E.g. Sun-Earth, Earth-Moon, Sun-Jupiter? Alternatively, you might like to reframe your question to ask about the general stability of the $L_1$ point for any two-body system. Please [edit] your question to provide further detail so that we can answer it.
Chappo Hasn't Forgotten
<gravity><earth><lagrange-point>
Does the Lagrange L1 point have a 'size'?
Ghost
# Does the Lagrange L1 point have a 'size'?

(Asked by: username_0 on 2019-09-25)

Like in cubic kilometers, what is the size of L1 "area of influence"? being unstable I guess that size can vary?

**Tags:** gravity, earth, lagrange-point
> **Comments:**
> **username_1**: No matter how you define the degree of relative stability at $L_1$, you would naturally expect the volume of that region to depend on the masses of the two bodies and the distance between them. Which two-body system did you have in mind? E.g. Sun-Earth, Earth-Moon, Sun-Jupiter? Alternatively, you might like to reframe your question to ask about the general stability of the $L_1$ point for any two-body system. Please [edit] your question to provide further detail so that we can answer it.  

---

## 2 answers

### Answer by username_2 on 2019-09-25. Score: 4

From [this source](http://www.astronomy.com/magazine/ask-astro/2013/10/lagrangian-points) I get:

> The size of these islands varies. Each planet in the solar system has
> its own Lagrangian points. The islands of stability get bigger farther
> from the Sun and also for more massive planets. The ones associated
> with Earth are roughly 500,000 miles (800,000 kilometers) wide. The
> biggest zones (at least in the solar system) are Neptune’s; they are
> about 2 billion miles (3.2 billion km) across.

L1, L2, and L3 are unstable. If a Sattelite ventures too far from the Lagrangian area it will fall towards the sun. As you can see from the image below. This image came from the source linked above.

[![enter image description here](https://i.sstatic.net/LAEoR.jpg)](https://i.sstatic.net/LAEoR.jpg)

> **Comments:**
> **username_0**: But L1 has a 800000 km diameter?  

---

### Answer by username_3 on 2019-09-25. Score: 2

I'm not sure how much this will add, but the points are exactly that - just points. Gravitational bodies are often reduced to points for the purpose of calculations, such as, centers of mass and barycenters are also points. The Lagrange points are the same - mathematically calculated points based on the two objects in orbit around their mutual barycenter. The article @jmh [posted says exactly that](http://www.astronomy.com/magazine/ask-astro/2013/10/lagrangian-points).

The L4 and L5 gravitational saddles where objects can have long term stable orbits and they can be very large, elongated regions generally in the same orbit ahead of or behind the orbiting planet, thought the size depends on a variety of factors. Jupiter's L4 and L5 saddle regions are enormous, for example. Larger across than the Earth's orbit around the Sun.

The L1-L3 points are different because there's no gravitational saddle where objects can remain in stable orbit. They still generate a region of low adjustment that I'm sure the size of those regions of low adjustment are pretty well understood by some at NASA. Satellites or telescopes that are put in L1 or L2 orbits require adjustment, but considerably less adjustment than a region in empty space away from a Lagrange point. They also remain in the same position relative to Earth, which has advantages.

The satellite region around L1/L2 that NASA uses could be defined as a kind of area of influence, but there's no exact measurement for where it ends as it gradually tapers off. Image below is not to scale.

[![enter image description here](https://i.sstatic.net/wD2zc.jpg)](https://i.sstatic.net/wD2zc.jpg)

[Source](https://jwst.nasa.gov/content/about/orbit.html)

The size also varies depending on which Lagrange point you're discussing. To my knowledge, we've only parked objects in the Earth-Sun L1 and L2 points. Moon-Earth Lagrange points have been discussed as parking spots for satellites, but never used to my knowledge.


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