<p>You asked</p>

<blockquote>
  <p>L3 is obscured by the Sun, so is that true for our viewpoint of the other planets?</p>
</blockquote>

<p>No. Each planet orbits with it's own <a href="http://en.wikipedia.org/wiki/Orbital_period" rel="nofollow">period</a> because each planet is at a different distance from the sun. So most of the time we can see the L3 point of each planet's orbit from Earth. Occasionally it goes behind the sun from our point of view.</p>

<blockquote>
  <p>For the Hilda's of Jupiter have we observed them in that position or is it that we have calculated their coordinates to be in the L3 position?</p>
</blockquote>

<p>The <a href="http://en.wikipedia.org/wiki/Hilda_family" rel="nofollow">Hilda family</a> do not occupy the Jupiter L3 point. They generally orbit closer to the sun than Jupiter, and orbit three times for every two orbits of Jupiter. Their orbits are interesting; they have eccentric orbits (up to 0.3) that in some cases cross the orbit of some of the <a href="http://en.wikipedia.org/wiki/Trojan_%28astronomy%29#Trojan_asteroids" rel="nofollow">Trojans</a>. You may have noticed that some of the Hildas also approach the Jupiter L3 point. At that point, and when other members of the family approach the Tojans at L4 and l5, the Hildas are moving more slowly. So the Sun's gravity gradually accelerates them, pulling them back to the lower, faster part of their orbits.</p>

<p>I have linked to the Wikipedia <a href="http://en.wikipedia.org/wiki/Hilda_family" rel="nofollow">Hilda family</a> page. The <a href="http://en.wikipedia.org/wiki/Lagrangian_point" rel="nofollow">Lagrangian point</a> page is also helpful.</p>

CC BY-SA 3.0
2015-04-06T02:45:34.533Z
I appreciate the clarification about the position of one of the groups of Hildas, and their interaction with the Trojans, the links are great, and that we can see L3!
AOC
CC BY-SA 3.0
2015-04-03T22:26:41.710Z
2015-04-03T23:17:21.687Z
2015-04-03T23:17:21.687Z
andy256
<p>From what I understand Earth's L3 is obscured by the Sun, so is that true for our viewpoint of the other planets? Or, are there times when other planets are on the other side of the Sun from Earth and we can see their L3 position? For the Hilda's of Jupiter have we observed them in that position or is it that we have calculated their coordinates to be in the L3 position?</p>

CC BY-SA 3.0
2015-04-04T02:38:57.337Z
L3, unlike L4 and L5, is not particularly stable; I wouldn't expect to find much there.
Keith Thompson
<lagrange-point>
Can we observe what objects exist at the L3 positiion of planets of our solar system?
AOC
# Can we observe what objects exist at the L3 positiion of planets of our solar system?

(Asked by: username_0 on 2015-04-03)

From what I understand Earth's L3 is obscured by the Sun, so is that true for our viewpoint of the other planets? Or, are there times when other planets are on the other side of the Sun from Earth and we can see their L3 position? For the Hilda's of Jupiter have we observed them in that position or is it that we have calculated their coordinates to be in the L3 position?

**Tags:** lagrange-point
> **Comments:**
> **username_1**: L3, unlike L4 and L5, is not particularly stable; I wouldn't expect to find much there.  

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## 1 answers

### Answer by username_2 on 2015-04-03. Score: 2 | Accepted answer

You asked

> L3 is obscured by the Sun, so is that true for our viewpoint of the other planets?

No. Each planet orbits with it's own [period](http://en.wikipedia.org/wiki/Orbital_period) because each planet is at a different distance from the sun. So most of the time we can see the L3 point of each planet's orbit from Earth. Occasionally it goes behind the sun from our point of view.

> For the Hilda's of Jupiter have we observed them in that position or is it that we have calculated their coordinates to be in the L3 position?

The [Hilda family](http://en.wikipedia.org/wiki/Hilda_family) do not occupy the Jupiter L3 point. They generally orbit closer to the sun than Jupiter, and orbit three times for every two orbits of Jupiter. Their orbits are interesting; they have eccentric orbits (up to 0.3) that in some cases cross the orbit of some of the [Trojans](http://en.wikipedia.org/wiki/Trojan_%28astronomy%29#Trojan_asteroids). You may have noticed that some of the Hildas also approach the Jupiter L3 point. At that point, and when other members of the family approach the Tojans at L4 and l5, the Hildas are moving more slowly. So the Sun's gravity gradually accelerates them, pulling them back to the lower, faster part of their orbits.

I have linked to the Wikipedia [Hilda family](http://en.wikipedia.org/wiki/Hilda_family) page. The [Lagrangian point](http://en.wikipedia.org/wiki/Lagrangian_point) page is also helpful.

> **Comments:**
> **username_0**: I appreciate the clarification about the position of one of the groups of Hildas, and their interaction with the Trojans, the links are great, and that we can see L3!  

---

