<p>The suspected theory of a giant impact most likely happened during the formation of our Solar System around 3 - 4 billion years ago. It is assumed that an Earth-size or larger proto-planet collided with Uranus.</p>

<p>If not all, most of the moons of Uranus were formed after that impact, since such an impact would release a tremendous amount of material into Uranus's orbit (just like the case with our Moon).</p>

<p>Any other moons that had formed before then would have been disrupted by the recent debris and been eliminated in time, possibly creating new smaller moons or the rings.</p>

<p>So far we know too little about Uranus.</p>

CC BY-SA 4.0
2020-05-15T07:38:30.367Z
So we need to fund more missions to go explore Uranus and Neptune! :)
usernumber
CC BY-SA 4.0
2020-05-15T13:01:43.467Z
Indeed. Most of the information we have is through Voyager 2, and that was back in 1986. If we have a new mission for Uranus, we would definitely lear much much more about it.
H.Aziz Kayıhan
CC BY-SA 4.0
2020-05-15T15:58:25.767Z
Hence the push and planning to get new Ice Giants missions such as this recent [Royal Society meeting](https://ice-giants.github.io/) and the [Ice Giants Mission Study](https://www.lpi.usra.edu/icegiants/mission_study/)
astrosnapper
CC BY-SA 4.0
2020-05-20T20:26:09.043Z
3-4 billion years ago??
ProfRob
CC BY-SA 4.0
2020-05-21T08:16:47.003Z
It is hard to tell when such an impact occurred, and no one source points to an exact timeline on this. It is believed that Uranus, just like Neptune, formed more inwards in the Solar System. So majority estimates that such a collision occurred somewhere between 3 to 4 billion years ago.
H.Aziz Kayıhan
CC BY-SA 4.0
2020-05-15T05:13:09.470Z
2020-05-20T06:57:34.103Z
2020-05-20T06:57:34.103Z
H.Aziz Kayıhan
<p>So the most accepted explanation for Uranus' axial tilt is that it once had a normal tilt like the other planets bar Venus (0° to 30°), but then a certain massive object collided with it and flipped it on its side.</p>

<p>But by that logic then shouldn't Uranus' moons be orbiting 0° to 30° relative to the orbital plane? (or whatever mild axial tilt Uranus had before the impact)</p>

<p>If they were formed before when Uranus still had a mild axial tilt then it makes no sense for them to be orbiting directly over present-day Uranus' equator. </p>

<uranus>
If the axial tilt of Uranus (97°) was caused by a giant impact, then why do its moons orbit around its equator at the same tilt (≈97°)?
user177107
# If the axial tilt of Uranus (97°) was caused by a giant impact, then why do its moons orbit around its equator at the same tilt (≈97°)?

(Asked by: username_0 on 2020-05-15)

So the most accepted explanation for Uranus' axial tilt is that it once had a normal tilt like the other planets bar Venus (0° to 30°), but then a certain massive object collided with it and flipped it on its side.

But by that logic then shouldn't Uranus' moons be orbiting 0° to 30° relative to the orbital plane? (or whatever mild axial tilt Uranus had before the impact)

If they were formed before when Uranus still had a mild axial tilt then it makes no sense for them to be orbiting directly over present-day Uranus' equator.

**Tags:** uranus


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## 1 answers

### Answer by username_1 on 2020-05-15. Score: 6

The suspected theory of a giant impact most likely happened during the formation of our Solar System around 3 - 4 billion years ago. It is assumed that an Earth-size or larger proto-planet collided with Uranus.

If not all, most of the moons of Uranus were formed after that impact, since such an impact would release a tremendous amount of material into Uranus's orbit (just like the case with our Moon).

Any other moons that had formed before then would have been disrupted by the recent debris and been eliminated in time, possibly creating new smaller moons or the rings.

So far we know too little about Uranus.

> **Comments:**
> **username_2**: So we need to fund more missions to go explore Uranus and Neptune! :)  
> **username_1**: Indeed. Most of the information we have is through Voyager 2, and that was back in 1986. If we have a new mission for Uranus, we would definitely lear much much more about it.  
> **username_3**: Hence the push and planning to get new Ice Giants missions such as this recent [Royal Society meeting](https://ice-giants.github.io/) and the [Ice Giants Mission Study](https://www.lpi.usra.edu/icegiants/mission_study/)  
> **username_4**: 3-4 billion years ago??  
> **username_1**: It is hard to tell when such an impact occurred, and no one source points to an exact timeline on this. It is believed that Uranus, just like Neptune, formed more inwards in the Solar System. So majority estimates that such a collision occurred somewhere between 3 to 4 billion years ago.  

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